static void cdev_default_release(struct kobject *kobj)
{
	struct cdev *p = container_of(kobj, struct cdev, kobj);
	struct kobject *parent = kobj->parent;

	cdev_purge(p);
	kobject_put(parent);
}


static inline int major_to_index(unsigned major)
{
	return major % CHRDEV_MAJOR_HASH_SIZE;
}

chardev: Avoid potential use-after-free in 'chrdev_open()'

'chrdev_open()' calls 'cdev_get()' to obtain a reference to the
'struct cdev *' stashed in the 'i_cdev' field of the target inode
structure. If the pointer is NULL, then it is initialised lazily by
looking up the kobject in the 'cdev_map' and so the whole procedure is
protected by the 'cdev_lock' spinlock to serialise initialisation of
the shared pointer.

Unfortunately, it is possible for the initialising thread to fail *after*
installing the new pointer, for example if the subsequent '->open()' call
on the file fails. In this case, 'cdev_put()' is called, the reference
count on the kobject is dropped and, if nobody else has taken a reference,
the release function is called which finally clears 'inode->i_cdev' from
'cdev_purge()' before potentially freeing the object. The problem here
is that a racing thread can happily take the 'cdev_lock' and see the
non-NULL pointer in the inode, which can result in a refcount increment
from zero and a warning:

  |  ------------[ cut here ]------------
  |  refcount_t: addition on 0; use-after-free.
  |  WARNING: CPU: 2 PID: 6385 at lib/refcount.c:25 refcount_warn_saturate+0x6d/0xf0
  |  Modules linked in:
  |  CPU: 2 PID: 6385 Comm: repro Not tainted 5.5.0-rc2+ #22
  |  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
  |  RIP: 0010:refcount_warn_saturate+0x6d/0xf0
  |  Code: 05 55 9a 15 01 01 e8 9d aa c8 ff 0f 0b c3 80 3d 45 9a 15 01 00 75 ce 48 c7 c7 00 9c 62 b3 c6 08
  |  RSP: 0018:ffffb524c1b9bc70 EFLAGS: 00010282
  |  RAX: 0000000000000000 RBX: ffff9e9da1f71390 RCX: 0000000000000000
  |  RDX: ffff9e9dbbd27618 RSI: ffff9e9dbbd18798 RDI: ffff9e9dbbd18798
  |  RBP: 0000000000000000 R08: 000000000000095f R09: 0000000000000039
  |  R10: 0000000000000000 R11: ffffb524c1b9bb20 R12: ffff9e9da1e8c700
  |  R13: ffffffffb25ee8b0 R14: 0000000000000000 R15: ffff9e9da1e8c700
  |  FS:  00007f3b87d26700(0000) GS:ffff9e9dbbd00000(0000) knlGS:0000000000000000
  |  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  |  CR2: 00007fc16909c000 CR3: 000000012df9c000 CR4: 00000000000006e0
  |  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  |  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  |  Call Trace:
  |   kobject_get+0x5c/0x60
  |   cdev_get+0x2b/0x60
  |   chrdev_open+0x55/0x220
  |   ? cdev_put.part.3+0x20/0x20
  |   do_dentry_open+0x13a/0x390
  |   path_openat+0x2c8/0x1470
  |   do_filp_open+0x93/0x100
  |   ? selinux_file_ioctl+0x17f/0x220
  |   do_sys_open+0x186/0x220
  |   do_syscall_64+0x48/0x150
  |   entry_SYSCALL_64_after_hwframe+0x44/0xa9
  |  RIP: 0033:0x7f3b87efcd0e
  |  Code: 89 54 24 08 e8 a3 f4 ff ff 8b 74 24 0c 48 8b 3c 24 41 89 c0 44 8b 54 24 08 b8 01 01 00 00 89 f4
  |  RSP: 002b:00007f3b87d259f0 EFLAGS: 00000293 ORIG_RAX: 0000000000000101
  |  RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f3b87efcd0e
  |  RDX: 0000000000000000 RSI: 00007f3b87d25a80 RDI: 00000000ffffff9c
  |  RBP: 00007f3b87d25e90 R08: 0000000000000000 R09: 0000000000000000
  |  R10: 0000000000000000 R11: 0000000000000293 R12: 00007ffe188f504e
  |  R13: 00007ffe188f504f R14: 00007f3b87d26700 R15: 0000000000000000
  |  ---[ end trace 24f53ca58db8180a ]---

Since 'cdev_get()' can already fail to obtain a reference, simply move
it over to use 'kobject_get_unless_zero()' instead of 'kobject_get()',
which will cause the racing thread to return -ENXIO if the initialising
thread fails unexpectedly.

Cc: Hillf Danton <hdanton@sina.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Reported-by: syzbot+82defefbbd8527e1c2cb@syzkaller.appspotmail.com
Signed-off-by: Will Deacon <will@kernel.org>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20191219120203.32691-1-will@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


void cdev_put(struct cdev *p)
{
	if (p) {
		struct module *owner = p->owner;
		kobject_put(&p->kobj);
		module_put(owner);
	}
}


static struct kobject *cdev_get(struct cdev *p)
{
	struct module *owner = p->owner;
	struct kobject *kobj;

	if (owner && !try_module_get(owner))
		return NULL;
	kobj = kobject_get_unless_zero(&p->kobj);
	if (!kobj)
		module_put(owner);
	return kobj;
}


static int find_dynamic_major(void)
{
	int i;
	struct char_device_struct *cd;

	for (i = ARRAY_SIZE(chrdevs)-1; i >= CHRDEV_MAJOR_DYN_END; i--) {
		if (chrdevs[i] == NULL)
			return i;
	}

	for (i = CHRDEV_MAJOR_DYN_EXT_START;
	     i >= CHRDEV_MAJOR_DYN_EXT_END; i--) {
		for (cd = chrdevs[major_to_index(i)]; cd; cd = cd->next)
			if (cd->major == i)
				break;

		if (cd == NULL)
			return i;
	}

	return -EBUSY;
}


void cdev_del(struct cdev *p)
{
	cdev_unmap(p->dev, p->count);
	kobject_put(&p->kobj);
}


void chrdev_show(struct seq_file *f, off_t offset)
{
	struct char_device_struct *cd;

	mutex_lock(&chrdevs_lock);
	for (cd = chrdevs[major_to_index(offset)]; cd; cd = cd->next) {
		if (cd->major == offset)
			seq_printf(f, "%3d %s\n", cd->major, cd->name);
	}
	mutex_unlock(&chrdevs_lock);
}


void unregister_chrdev_region(dev_t from, unsigned count)
{
	dev_t to = from + count;
	dev_t n, next;

	for (n = from; n < to; n = next) {
		next = MKDEV(MAJOR(n)+1, 0);
		if (next > to)
			next = to;
		kfree(__unregister_chrdev_region(MAJOR(n), MINOR(n), next - n));
	}
}


static MagickBooleanType WriteTIFFImage(const ImageInfo *image_info,
  Image *image,ExceptionInfo *exception)
{
  const char
    *mode,
    *option;

  CompressionType
    compression;

  EndianType
    endian_type;

  MagickBooleanType
    adjoin,
    debug,
    preserve_compression,
    status;

  MagickOffsetType
    scene;

  QuantumInfo
    *quantum_info;

  QuantumType
    quantum_type;

  register ssize_t
    i;

  size_t
    imageListLength,
    length;

  ssize_t
    y;

  TIFF
    *tiff;

  TIFFInfo
    tiff_info;

  uint16
    bits_per_sample,
    compress_tag,
    endian,
    photometric,
    predictor;

  unsigned char
    *pixels;

  void
    *sans[2] = { NULL, NULL };

  /*
    Open TIFF file.
  */
  assert(image_info != (const ImageInfo *) NULL);
  assert(image_info->signature == MagickCoreSignature);
  assert(image != (Image *) NULL);
  assert(image->signature == MagickCoreSignature);
  if (image->debug != MagickFalse)
    (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
  assert(exception != (ExceptionInfo *) NULL);
  assert(exception->signature == MagickCoreSignature);
  status=OpenBlob(image_info,image,WriteBinaryBlobMode,exception);
  if (status == MagickFalse)
    return(status);
  (void) SetMagickThreadValue(tiff_exception,exception);
  endian_type=(HOST_FILLORDER == FILLORDER_LSB2MSB) ? LSBEndian : MSBEndian;
  option=GetImageOption(image_info,"tiff:endian");
  if (option != (const char *) NULL)
    {
      if (LocaleNCompare(option,"msb",3) == 0)
        endian_type=MSBEndian;
      if (LocaleNCompare(option,"lsb",3) == 0)
        endian_type=LSBEndian;
    }
  mode=endian_type == LSBEndian ? "wl" : "wb";
#if defined(TIFF_VERSION_BIG)
  if (LocaleCompare(image_info->magick,"TIFF64") == 0)
    mode=endian_type == LSBEndian ? "wl8" : "wb8";
#endif
  tiff=TIFFClientOpen(image->filename,mode,(thandle_t) image,TIFFReadBlob,
    TIFFWriteBlob,TIFFSeekBlob,TIFFCloseBlob,TIFFGetBlobSize,TIFFMapBlob,
    TIFFUnmapBlob);
  if (tiff == (TIFF *) NULL)
    return(MagickFalse);
  if (exception->severity > ErrorException)
    {
      TIFFClose(tiff);
      return(MagickFalse);
    }
  (void) DeleteImageProfile(image,"tiff:37724");
  scene=0;
  debug=IsEventLogging();
  (void) debug;
  adjoin=image_info->adjoin;
  imageListLength=GetImageListLength(image);
  option=GetImageOption(image_info,"tiff:preserve-compression");
  preserve_compression=IsStringTrue(option);
  do
  {
    /*
      Initialize TIFF fields.
    */
    (void) IsImageMonochrome(image);
    if ((image_info->type != UndefinedType) &&
        (image_info->type != OptimizeType))
      (void) SetImageType(image,image_info->type,exception);
    compression=image_info->compression;
    if (preserve_compression != MagickFalse)
      compression=image->compression;
    switch (compression)
    {
      case FaxCompression:
      case Group4Compression:
      {
        if (IsImageMonochrome(image) == MagickFalse)
          {
            if (IsImageGray(image) == MagickFalse)
              (void) SetImageType(image,BilevelType,exception);
            else
              (void) SetImageDepth(image,1,exception);
          }
        image->depth=1;
        break;
      }
      case JPEGCompression:
      {
        (void) SetImageStorageClass(image,DirectClass,exception);
        (void) SetImageDepth(image,8,exception);
        break;
      }
      default:
        break;
    }
    quantum_info=AcquireQuantumInfo(image_info,image);
    if (quantum_info == (QuantumInfo *) NULL)
      ThrowWriterException(ResourceLimitError,"MemoryAllocationFailed");
    if ((image->storage_class != PseudoClass) && (image->depth >= 32) &&
        (quantum_info->format == UndefinedQuantumFormat) &&
        (IsHighDynamicRangeImage(image,exception) != MagickFalse))
      {
        status=SetQuantumFormat(image,quantum_info,FloatingPointQuantumFormat);
        if (status == MagickFalse)
          {
            quantum_info=DestroyQuantumInfo(quantum_info);
            ThrowWriterException(ResourceLimitError,"MemoryAllocationFailed");
          }
      }
    if ((LocaleCompare(image_info->magick,"PTIF") == 0) &&
        (GetPreviousImageInList(image) != (Image *) NULL))
      (void) TIFFSetField(tiff,TIFFTAG_SUBFILETYPE,FILETYPE_REDUCEDIMAGE);
    if ((image->columns != (uint32) image->columns) ||
        (image->rows != (uint32) image->rows))
      ThrowWriterException(ImageError,"WidthOrHeightExceedsLimit");
    (void) TIFFSetField(tiff,TIFFTAG_IMAGELENGTH,(uint32) image->rows);
    (void) TIFFSetField(tiff,TIFFTAG_IMAGEWIDTH,(uint32) image->columns);
    switch (compression)
    {
      case FaxCompression:
      {
        compress_tag=COMPRESSION_CCITTFAX3;
        option=GetImageOption(image_info,"quantum:polarity");
        if (option == (const char *) NULL)
          SetQuantumMinIsWhite(quantum_info,MagickTrue);
        break;
      }
      case Group4Compression:
      {
        compress_tag=COMPRESSION_CCITTFAX4;
        option=GetImageOption(image_info,"quantum:polarity");
        if (option == (const char *) NULL)
          SetQuantumMinIsWhite(quantum_info,MagickTrue);
        break;
      }
#if defined(COMPRESSION_JBIG)
      case JBIG1Compression:
      {
        compress_tag=COMPRESSION_JBIG;
        break;
      }
#endif
      case JPEGCompression:
      {
        compress_tag=COMPRESSION_JPEG;
        break;
      }
#if defined(COMPRESSION_LZMA)
      case LZMACompression:
      {
        compress_tag=COMPRESSION_LZMA;
        break;
      }
#endif
      case LZWCompression:
      {
        compress_tag=COMPRESSION_LZW;
        break;
      }
      case RLECompression:
      {
        compress_tag=COMPRESSION_PACKBITS;
        break;
      }
      case ZipCompression:
      {
        compress_tag=COMPRESSION_ADOBE_DEFLATE;
        break;
      }
#if defined(COMPRESSION_ZSTD)
      case ZstdCompression:
      {
        compress_tag=COMPRESSION_ZSTD;
        break;
      }
#endif
      case NoCompression:
      default:
      {
        compress_tag=COMPRESSION_NONE;
        break;
      }
    }
#if defined(MAGICKCORE_HAVE_TIFFISCODECCONFIGURED) || (TIFFLIB_VERSION > 20040919)
    if ((compress_tag != COMPRESSION_NONE) &&
        (TIFFIsCODECConfigured(compress_tag) == 0))
      {
        (void) ThrowMagickException(exception,GetMagickModule(),CoderError,
          "CompressionNotSupported","`%s'",CommandOptionToMnemonic(
          MagickCompressOptions,(ssize_t) compression));
        compress_tag=COMPRESSION_NONE;
        compression=NoCompression;
      }
#else
      switch (compress_tag)
      {
#if defined(CCITT_SUPPORT)
        case COMPRESSION_CCITTFAX3:
        case COMPRESSION_CCITTFAX4:
#endif
#if defined(YCBCR_SUPPORT) && defined(JPEG_SUPPORT)
        case COMPRESSION_JPEG:
#endif
#if defined(LZMA_SUPPORT) && defined(COMPRESSION_LZMA)
        case COMPRESSION_LZMA:
#endif
#if defined(LZW_SUPPORT)
        case COMPRESSION_LZW:
#endif
#if defined(PACKBITS_SUPPORT)
        case COMPRESSION_PACKBITS:
#endif
#if defined(ZIP_SUPPORT)
        case COMPRESSION_ADOBE_DEFLATE:
#endif
        case COMPRESSION_NONE:
          break;
        default:
        {
          (void) ThrowMagickException(exception,GetMagickModule(),CoderError,
            "CompressionNotSupported","`%s'",CommandOptionToMnemonic(
            MagickCompressOptions,(ssize_t) compression));
          compress_tag=COMPRESSION_NONE;
          compression=NoCompression;
          break;
        }
      }
#endif
    if (image->colorspace == CMYKColorspace)
      {
        photometric=PHOTOMETRIC_SEPARATED;
        (void) TIFFSetField(tiff,TIFFTAG_SAMPLESPERPIXEL,4);
        (void) TIFFSetField(tiff,TIFFTAG_INKSET,INKSET_CMYK);
      }
    else
      {
        /*
          Full color TIFF raster.
        */
        if (image->colorspace == LabColorspace)
          {
            photometric=PHOTOMETRIC_CIELAB;
            EncodeLabImage(image,exception);
          }
        else
          if (IsYCbCrCompatibleColorspace(image->colorspace) != MagickFalse)
            {
              photometric=PHOTOMETRIC_YCBCR;
              (void) TIFFSetField(tiff,TIFFTAG_YCBCRSUBSAMPLING,1,1);
              (void) SetImageStorageClass(image,DirectClass,exception);
              status=SetQuantumDepth(image,quantum_info,8);
              if (status == MagickFalse)
                ThrowWriterException(ResourceLimitError,
                  "MemoryAllocationFailed");
            }
          else
            photometric=PHOTOMETRIC_RGB;
        (void) TIFFSetField(tiff,TIFFTAG_SAMPLESPERPIXEL,3);
        if ((image_info->type != TrueColorType) &&
            (image_info->type != TrueColorAlphaType))
          {
            if ((image_info->type != PaletteType) &&
                (SetImageGray(image,exception) != MagickFalse))
              {
                photometric=(uint16) (quantum_info->min_is_white !=
                  MagickFalse ? PHOTOMETRIC_MINISWHITE :
                  PHOTOMETRIC_MINISBLACK);
                (void) TIFFSetField(tiff,TIFFTAG_SAMPLESPERPIXEL,1);
                if ((image->depth == 1) &&
                    (image->alpha_trait == UndefinedPixelTrait))
                  SetImageMonochrome(image,exception);
              }
            else
              if (image->storage_class == PseudoClass)
                {
                  size_t
                    depth;

                  /*
                    Colormapped TIFF raster.
                  */
                  (void) TIFFSetField(tiff,TIFFTAG_SAMPLESPERPIXEL,1);
                  photometric=PHOTOMETRIC_PALETTE;
                  depth=1;
                  while ((GetQuantumRange(depth)+1) < image->colors)
                    depth<<=1;
                  status=SetQuantumDepth(image,quantum_info,depth);
                  if (status == MagickFalse)
                    ThrowWriterException(ResourceLimitError,
                      "MemoryAllocationFailed");
                }
          }
      }
    (void) TIFFGetFieldDefaulted(tiff,TIFFTAG_FILLORDER,&endian,sans);
    if ((compress_tag == COMPRESSION_CCITTFAX3) ||
        (compress_tag == COMPRESSION_CCITTFAX4))
      {
         if ((photometric != PHOTOMETRIC_MINISWHITE) &&
             (photometric != PHOTOMETRIC_MINISBLACK))
          {
            compress_tag=COMPRESSION_NONE;
            endian=FILLORDER_MSB2LSB;
          }
      }
    option=GetImageOption(image_info,"tiff:fill-order");
    if (option != (const char *) NULL)
      {
        if (LocaleNCompare(option,"msb",3) == 0)
          endian=FILLORDER_MSB2LSB;
        if (LocaleNCompare(option,"lsb",3) == 0)
          endian=FILLORDER_LSB2MSB;
      }
    (void) TIFFSetField(tiff,TIFFTAG_COMPRESSION,compress_tag);
    (void) TIFFSetField(tiff,TIFFTAG_FILLORDER,endian);
    (void) TIFFSetField(tiff,TIFFTAG_BITSPERSAMPLE,quantum_info->depth);
    if (image->alpha_trait != UndefinedPixelTrait)
      {
        uint16
          extra_samples,
          sample_info[1],
          samples_per_pixel;

        /*
          TIFF has a matte channel.
        */
        extra_samples=1;
        sample_info[0]=EXTRASAMPLE_UNASSALPHA;
        option=GetImageOption(image_info,"tiff:alpha");
        if (option != (const char *) NULL)
          {
            if (LocaleCompare(option,"associated") == 0)
              sample_info[0]=EXTRASAMPLE_ASSOCALPHA;
            else
              if (LocaleCompare(option,"unspecified") == 0)
                sample_info[0]=EXTRASAMPLE_UNSPECIFIED;
          }
        (void) TIFFGetFieldDefaulted(tiff,TIFFTAG_SAMPLESPERPIXEL,
          &samples_per_pixel,sans);
        (void) TIFFSetField(tiff,TIFFTAG_SAMPLESPERPIXEL,samples_per_pixel+1);
        (void) TIFFSetField(tiff,TIFFTAG_EXTRASAMPLES,extra_samples,
          &sample_info);
        if (sample_info[0] == EXTRASAMPLE_ASSOCALPHA)
          SetQuantumAlphaType(quantum_info,AssociatedQuantumAlpha);
      }
    (void) TIFFSetField(tiff,TIFFTAG_PHOTOMETRIC,photometric);
    switch (quantum_info->format)
    {
      case FloatingPointQuantumFormat:
      {
        (void) TIFFSetField(tiff,TIFFTAG_SAMPLEFORMAT,SAMPLEFORMAT_IEEEFP);
        (void) TIFFSetField(tiff,TIFFTAG_SMINSAMPLEVALUE,quantum_info->minimum);
        (void) TIFFSetField(tiff,TIFFTAG_SMAXSAMPLEVALUE,quantum_info->maximum);
        break;
      }
      case SignedQuantumFormat:
      {
        (void) TIFFSetField(tiff,TIFFTAG_SAMPLEFORMAT,SAMPLEFORMAT_INT);
        break;
      }
      case UnsignedQuantumFormat:
      {
        (void) TIFFSetField(tiff,TIFFTAG_SAMPLEFORMAT,SAMPLEFORMAT_UINT);
        break;
      }
      default:
        break;
    }
    (void) TIFFSetField(tiff,TIFFTAG_PLANARCONFIG,PLANARCONFIG_CONTIG);
    if (photometric == PHOTOMETRIC_RGB)
      if ((image_info->interlace == PlaneInterlace) ||
          (image_info->interlace == PartitionInterlace))
        (void) TIFFSetField(tiff,TIFFTAG_PLANARCONFIG,PLANARCONFIG_SEPARATE);
    predictor=0;
    switch (compress_tag)
    {
      case COMPRESSION_JPEG:
      {
#if defined(JPEG_SUPPORT)
        if (image_info->quality != UndefinedCompressionQuality)
          (void) TIFFSetField(tiff,TIFFTAG_JPEGQUALITY,image_info->quality);
        (void) TIFFSetField(tiff,TIFFTAG_JPEGCOLORMODE,JPEGCOLORMODE_RAW);
        if (IssRGBCompatibleColorspace(image->colorspace) != MagickFalse)
          {
            const char
              *value;

            (void) TIFFSetField(tiff,TIFFTAG_JPEGCOLORMODE,JPEGCOLORMODE_RGB);
            if (IsYCbCrCompatibleColorspace(image->colorspace) != MagickFalse)
              {
                const char
                  *sampling_factor;

                GeometryInfo
                  geometry_info;

                MagickStatusType
                  flags;

                sampling_factor=(const char *) NULL;
                value=GetImageProperty(image,"jpeg:sampling-factor",exception);
                if (value != (char *) NULL)
                  {
                    sampling_factor=value;
                    if (image->debug != MagickFalse)
                      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                        "  Input sampling-factors=%s",sampling_factor);
                  }
                if (image_info->sampling_factor != (char *) NULL)
                  sampling_factor=image_info->sampling_factor;
                if (sampling_factor != (const char *) NULL)
                  {
                    flags=ParseGeometry(sampling_factor,&geometry_info);
                    if ((flags & SigmaValue) == 0)
                      geometry_info.sigma=geometry_info.rho;
                    (void) TIFFSetField(tiff,TIFFTAG_YCBCRSUBSAMPLING,(uint16)
                      geometry_info.rho,(uint16) geometry_info.sigma);
                  }
                }
          }
        (void) TIFFGetFieldDefaulted(tiff,TIFFTAG_BITSPERSAMPLE,
          &bits_per_sample,sans);
        if (bits_per_sample == 12)
          (void) TIFFSetField(tiff,TIFFTAG_JPEGTABLESMODE,JPEGTABLESMODE_QUANT);
#endif
        break;
      }
      case COMPRESSION_ADOBE_DEFLATE:
      {
        (void) TIFFGetFieldDefaulted(tiff,TIFFTAG_BITSPERSAMPLE,
          &bits_per_sample,sans);
        if (((photometric == PHOTOMETRIC_RGB) ||
             (photometric == PHOTOMETRIC_SEPARATED) ||
             (photometric == PHOTOMETRIC_MINISBLACK)) &&
            ((bits_per_sample == 8) || (bits_per_sample == 16)))
          predictor=PREDICTOR_HORIZONTAL;
        (void) TIFFSetField(tiff,TIFFTAG_ZIPQUALITY,(long) (
          image_info->quality == UndefinedCompressionQuality ? 7 :
          MagickMin((ssize_t) image_info->quality/10,9)));
        break;
      }
      case COMPRESSION_CCITTFAX3:
      {
        /*
          Byte-aligned EOL.
        */
        (void) TIFFSetField(tiff,TIFFTAG_GROUP3OPTIONS,4);
        break;
      }
      case COMPRESSION_CCITTFAX4:
        break;
#if defined(LZMA_SUPPORT) && defined(COMPRESSION_LZMA)
      case COMPRESSION_LZMA:
      {
        if (((photometric == PHOTOMETRIC_RGB) ||
             (photometric == PHOTOMETRIC_SEPARATED) ||
             (photometric == PHOTOMETRIC_MINISBLACK)) &&
            ((bits_per_sample == 8) || (bits_per_sample == 16)))
          predictor=PREDICTOR_HORIZONTAL;
        (void) TIFFSetField(tiff,TIFFTAG_LZMAPRESET,(long) (
          image_info->quality == UndefinedCompressionQuality ? 7 :
          MagickMin((ssize_t) image_info->quality/10,9)));
        break;
      }
#endif
      case COMPRESSION_LZW:
      {
        (void) TIFFGetFieldDefaulted(tiff,TIFFTAG_BITSPERSAMPLE,
          &bits_per_sample,sans);
        if (((photometric == PHOTOMETRIC_RGB) ||
             (photometric == PHOTOMETRIC_SEPARATED) ||
             (photometric == PHOTOMETRIC_MINISBLACK)) &&
            ((bits_per_sample == 8) || (bits_per_sample == 16)))
          predictor=PREDICTOR_HORIZONTAL;
        break;
      }
#if defined(WEBP_SUPPORT) && defined(COMPRESSION_WEBP)
      case COMPRESSION_WEBP:
      {
        (void) TIFFGetFieldDefaulted(tiff,TIFFTAG_BITSPERSAMPLE,
          &bits_per_sample,sans);
        if (((photometric == PHOTOMETRIC_RGB) ||
             (photometric == PHOTOMETRIC_SEPARATED) ||
             (photometric == PHOTOMETRIC_MINISBLACK)) &&
            ((bits_per_sample == 8) || (bits_per_sample == 16)))
          predictor=PREDICTOR_HORIZONTAL;
        (void) TIFFSetField(tiff,TIFFTAG_WEBP_LEVEL,image_info->quality);
        if (image_info->quality >= 100)
          (void) TIFFSetField(tiff,TIFFTAG_WEBP_LOSSLESS,1);
        break;
      }
#endif
#if defined(ZSTD_SUPPORT) && defined(COMPRESSION_ZSTD)
      case COMPRESSION_ZSTD:
      {
        (void) TIFFGetFieldDefaulted(tiff,TIFFTAG_BITSPERSAMPLE,
          &bits_per_sample,sans);
        if (((photometric == PHOTOMETRIC_RGB) ||
             (photometric == PHOTOMETRIC_SEPARATED) ||
             (photometric == PHOTOMETRIC_MINISBLACK)) &&
            ((bits_per_sample == 8) || (bits_per_sample == 16)))
          predictor=PREDICTOR_HORIZONTAL;
        (void) TIFFSetField(tiff,TIFFTAG_ZSTD_LEVEL,22*image_info->quality/
          100.0);
        break;
      }
#endif
      default:
        break;
    }
    if (quantum_info->format == FloatingPointQuantumFormat)
      predictor=PREDICTOR_FLOATINGPOINT;
    option=GetImageOption(image_info,"tiff:predictor");
    if (option != (const char * ) NULL)
      predictor=(uint16) strtol(option,(char **) NULL,10);
    if (predictor != 0)
      (void) TIFFSetField(tiff,TIFFTAG_PREDICTOR,predictor);
    if ((image->resolution.x != 0.0) && (image->resolution.y != 0.0))
      {
        unsigned short
          units;

        /*
          Set image resolution.
        */
        units=RESUNIT_NONE;
        if (image->units == PixelsPerInchResolution)
          units=RESUNIT_INCH;
        if (image->units == PixelsPerCentimeterResolution)
          units=RESUNIT_CENTIMETER;
        (void) TIFFSetField(tiff,TIFFTAG_RESOLUTIONUNIT,(uint16) units);
        (void) TIFFSetField(tiff,TIFFTAG_XRESOLUTION,image->resolution.x);
        (void) TIFFSetField(tiff,TIFFTAG_YRESOLUTION,image->resolution.y);
        if ((image->page.x < 0) || (image->page.y < 0))
          (void) ThrowMagickException(exception,GetMagickModule(),CoderError,
            "TIFF: negative image positions unsupported","%s",image->filename);
        if ((image->page.x > 0) && (image->resolution.x > 0.0))
          {
            /*
              Set horizontal image position.
            */
            (void) TIFFSetField(tiff,TIFFTAG_XPOSITION,(float) image->page.x/
              image->resolution.x);
          }
        if ((image->page.y > 0) && (image->resolution.y > 0.0))
          {
            /*
              Set vertical image position.
            */
            (void) TIFFSetField(tiff,TIFFTAG_YPOSITION,(float) image->page.y/
              image->resolution.y);
          }
      }
    if (image->chromaticity.white_point.x != 0.0)
      {
        float
          chromaticity[6];

        /*
          Set image chromaticity.
        */
        chromaticity[0]=(float) image->chromaticity.red_primary.x;
        chromaticity[1]=(float) image->chromaticity.red_primary.y;
        chromaticity[2]=(float) image->chromaticity.green_primary.x;
        chromaticity[3]=(float) image->chromaticity.green_primary.y;
        chromaticity[4]=(float) image->chromaticity.blue_primary.x;
        chromaticity[5]=(float) image->chromaticity.blue_primary.y;
        (void) TIFFSetField(tiff,TIFFTAG_PRIMARYCHROMATICITIES,chromaticity);
        chromaticity[0]=(float) image->chromaticity.white_point.x;
        chromaticity[1]=(float) image->chromaticity.white_point.y;
        (void) TIFFSetField(tiff,TIFFTAG_WHITEPOINT,chromaticity);
      }
    option=GetImageOption(image_info,"tiff:write-layers");
    if (IsStringTrue(option) != MagickFalse)
      {
        (void) TIFFWritePhotoshopLayers(image,image_info,endian_type,exception);
        adjoin=MagickFalse;
      }
    if ((LocaleCompare(image_info->magick,"PTIF") != 0) &&
        (adjoin != MagickFalse) && (imageListLength > 1))
      {
        (void) TIFFSetField(tiff,TIFFTAG_SUBFILETYPE,FILETYPE_PAGE);
        if (image->scene != 0)
          (void) TIFFSetField(tiff,TIFFTAG_PAGENUMBER,(uint16) image->scene,
            imageListLength);
      }
    if (image->orientation != UndefinedOrientation)
      (void) TIFFSetField(tiff,TIFFTAG_ORIENTATION,(uint16) image->orientation);
    else
      (void) TIFFSetField(tiff,TIFFTAG_ORIENTATION,ORIENTATION_TOPLEFT);
    TIFFSetProfiles(tiff,image);
    {
      uint16
        page,
        pages;

      page=(uint16) scene;
      pages=(uint16) imageListLength;
      if ((LocaleCompare(image_info->magick,"PTIF") != 0) &&
          (adjoin != MagickFalse) && (pages > 1))
        (void) TIFFSetField(tiff,TIFFTAG_SUBFILETYPE,FILETYPE_PAGE);
      (void) TIFFSetField(tiff,TIFFTAG_PAGENUMBER,page,pages);
    }
    (void) TIFFSetProperties(tiff,adjoin,image,exception);
DisableMSCWarning(4127)
    if (0)
RestoreMSCWarning
      (void) TIFFSetEXIFProperties(tiff,image,exception);
    /*
      Write image scanlines.
    */
    if (GetTIFFInfo(image_info,tiff,&tiff_info) == MagickFalse)
      ThrowWriterException(ResourceLimitError,"MemoryAllocationFailed");
    if (compress_tag == COMPRESSION_CCITTFAX4)
      (void) TIFFSetField(tiff,TIFFTAG_ROWSPERSTRIP,(uint32) image->rows);
    quantum_info->endian=LSBEndian;
    pixels=(unsigned char *) GetQuantumPixels(quantum_info);
    tiff_info.scanline=(unsigned char *) GetQuantumPixels(quantum_info);
    switch (photometric)
    {
      case PHOTOMETRIC_CIELAB:
      case PHOTOMETRIC_YCBCR:
      case PHOTOMETRIC_RGB:
      {
        /*
          RGB TIFF image.
        */
        switch (image_info->interlace)
        {
          case NoInterlace:
          default:
          {
            quantum_type=RGBQuantum;
            if (image->alpha_trait != UndefinedPixelTrait)
              quantum_type=RGBAQuantum;
            for (y=0; y < (ssize_t) image->rows; y++)
            {
              register const Quantum
                *magick_restrict p;

              p=GetVirtualPixels(image,0,y,image->columns,1,exception);
              if (p == (const Quantum *) NULL)
                break;
              length=ExportQuantumPixels(image,(CacheView *) NULL,quantum_info,
                quantum_type,pixels,exception);
              (void) length;
              if (TIFFWritePixels(tiff,&tiff_info,y,0,image) == -1)
                break;
              if (image->previous == (Image *) NULL)
                {
                  status=SetImageProgress(image,SaveImageTag,(MagickOffsetType)
                    y,image->rows);
                  if (status == MagickFalse)
                    break;
                }
            }
            break;
          }
          case PlaneInterlace:
          case PartitionInterlace:
          {
            /*
              Plane interlacing:  RRRRRR...GGGGGG...BBBBBB...
            */
            for (y=0; y < (ssize_t) image->rows; y++)
            {
              register const Quantum
                *magick_restrict p;

              p=GetVirtualPixels(image,0,y,image->columns,1,exception);
              if (p == (const Quantum *) NULL)
                break;
              length=ExportQuantumPixels(image,(CacheView *) NULL,quantum_info,
                RedQuantum,pixels,exception);
              if (TIFFWritePixels(tiff,&tiff_info,y,0,image) == -1)
                break;
            }
            if (image->previous == (Image *) NULL)
              {
                status=SetImageProgress(image,SaveImageTag,100,400);
                if (status == MagickFalse)
                  break;
              }
            for (y=0; y < (ssize_t) image->rows; y++)
            {
              register const Quantum
                *magick_restrict p;

              p=GetVirtualPixels(image,0,y,image->columns,1,exception);
              if (p == (const Quantum *) NULL)
                break;
              length=ExportQuantumPixels(image,(CacheView *) NULL,quantum_info,
                GreenQuantum,pixels,exception);
              if (TIFFWritePixels(tiff,&tiff_info,y,1,image) == -1)
                break;
            }
            if (image->previous == (Image *) NULL)
              {
                status=SetImageProgress(image,SaveImageTag,200,400);
                if (status == MagickFalse)
                  break;
              }
            for (y=0; y < (ssize_t) image->rows; y++)
            {
              register const Quantum
                *magick_restrict p;

              p=GetVirtualPixels(image,0,y,image->columns,1,exception);
              if (p == (const Quantum *) NULL)
                break;
              length=ExportQuantumPixels(image,(CacheView *) NULL,quantum_info,
                BlueQuantum,pixels,exception);
              if (TIFFWritePixels(tiff,&tiff_info,y,2,image) == -1)
                break;
            }
            if (image->previous == (Image *) NULL)
              {
                status=SetImageProgress(image,SaveImageTag,300,400);
                if (status == MagickFalse)
                  break;
              }
            if (image->alpha_trait != UndefinedPixelTrait)
              for (y=0; y < (ssize_t) image->rows; y++)
              {
                register const Quantum
                  *magick_restrict p;

                p=GetVirtualPixels(image,0,y,image->columns,1,exception);
                if (p == (const Quantum *) NULL)
                  break;
                length=ExportQuantumPixels(image,(CacheView *) NULL,
                  quantum_info,AlphaQuantum,pixels,exception);
                if (TIFFWritePixels(tiff,&tiff_info,y,3,image) == -1)
                  break;
              }
            if (image->previous == (Image *) NULL)
              {
                status=SetImageProgress(image,SaveImageTag,400,400);
                if (status == MagickFalse)
                  break;
              }
            break;
          }
        }
        break;
      }
      case PHOTOMETRIC_SEPARATED:
      {
        /*
          CMYK TIFF image.
        */
        quantum_type=CMYKQuantum;
        if (image->alpha_trait != UndefinedPixelTrait)
          quantum_type=CMYKAQuantum;
        if (image->colorspace != CMYKColorspace)
          (void) TransformImageColorspace(image,CMYKColorspace,exception);
        for (y=0; y < (ssize_t) image->rows; y++)
        {
          register const Quantum
            *magick_restrict p;

          p=GetVirtualPixels(image,0,y,image->columns,1,exception);
          if (p == (const Quantum *) NULL)
            break;
          length=ExportQuantumPixels(image,(CacheView *) NULL,quantum_info,
            quantum_type,pixels,exception);
          if (TIFFWritePixels(tiff,&tiff_info,y,0,image) == -1)
            break;
          if (image->previous == (Image *) NULL)
            {
              status=SetImageProgress(image,SaveImageTag,(MagickOffsetType) y,
                image->rows);
              if (status == MagickFalse)
                break;
            }
        }
        break;
      }
      case PHOTOMETRIC_PALETTE:
      {
        uint16
          *blue,
          *green,
          *red;

        /*
          Colormapped TIFF image.
        */
        red=(uint16 *) AcquireQuantumMemory(65536,sizeof(*red));
        green=(uint16 *) AcquireQuantumMemory(65536,sizeof(*green));
        blue=(uint16 *) AcquireQuantumMemory(65536,sizeof(*blue));
        if ((red == (uint16 *) NULL) || (green == (uint16 *) NULL) ||
            (blue == (uint16 *) NULL))
          {
            if (red != (uint16 *) NULL)
              red=(uint16 *) RelinquishMagickMemory(red);
            if (green != (uint16 *) NULL)
              green=(uint16 *) RelinquishMagickMemory(green);
            if (blue != (uint16 *) NULL)
              blue=(uint16 *) RelinquishMagickMemory(blue);
            ThrowWriterException(ResourceLimitError,"MemoryAllocationFailed");
          }
        /*
          Initialize TIFF colormap.
        */
        (void) memset(red,0,65536*sizeof(*red));
        (void) memset(green,0,65536*sizeof(*green));
        (void) memset(blue,0,65536*sizeof(*blue));
        for (i=0; i < (ssize_t) image->colors; i++)
        {
          red[i]=ScaleQuantumToShort(image->colormap[i].red);
          green[i]=ScaleQuantumToShort(image->colormap[i].green);
          blue[i]=ScaleQuantumToShort(image->colormap[i].blue);
        }
        (void) TIFFSetField(tiff,TIFFTAG_COLORMAP,red,green,blue);
        red=(uint16 *) RelinquishMagickMemory(red);
        green=(uint16 *) RelinquishMagickMemory(green);
        blue=(uint16 *) RelinquishMagickMemory(blue);
      }
      default:
      {
        /*
          Convert PseudoClass packets to contiguous grayscale scanlines.
        */
        quantum_type=IndexQuantum;
        if (image->alpha_trait != UndefinedPixelTrait)
          {
            if (photometric != PHOTOMETRIC_PALETTE)
              quantum_type=GrayAlphaQuantum;
            else
              quantum_type=IndexAlphaQuantum;
           }
         else
           if (photometric != PHOTOMETRIC_PALETTE)
             quantum_type=GrayQuantum;
        for (y=0; y < (ssize_t) image->rows; y++)
        {
          register const Quantum
            *magick_restrict p;

          p=GetVirtualPixels(image,0,y,image->columns,1,exception);
          if (p == (const Quantum *) NULL)
            break;
          length=ExportQuantumPixels(image,(CacheView *) NULL,quantum_info,
            quantum_type,pixels,exception);
          if (TIFFWritePixels(tiff,&tiff_info,y,0,image) == -1)
            break;
          if (image->previous == (Image *) NULL)
            {
              status=SetImageProgress(image,SaveImageTag,(MagickOffsetType) y,
                image->rows);
              if (status == MagickFalse)
                break;
            }
        }
        break;
      }
    }
    quantum_info=DestroyQuantumInfo(quantum_info);
    if (image->colorspace == LabColorspace)
      DecodeLabImage(image,exception);
    DestroyTIFFInfo(&tiff_info);
    /* TIFFPrintDirectory(tiff,stdout,MagickFalse); */
    if (TIFFWriteDirectory(tiff) == 0)
      {
        status=MagickFalse;
        break;
      }
    image=SyncNextImageInList(image);
    if (image == (Image *) NULL)
      break;
    status=SetImageProgress(image,SaveImagesTag,scene++,imageListLength);
    if (status == MagickFalse)
      break;
  } while (adjoin != MagickFalse);
  TIFFClose(tiff);
  return(status);
}

possible TIFF related-heap buffer overflow (alert & POC by Hardik Shah)


static MagickBooleanType WriteGROUP4Image(const ImageInfo *image_info,
  Image *image,ExceptionInfo *exception)
{
  char
    filename[MagickPathExtent];

  FILE
    *file;

  Image
    *huffman_image;

  ImageInfo
    *write_info;

  int
    unique_file;

  MagickBooleanType
    status;

  register ssize_t
    i;

  ssize_t
    count;

  TIFF
    *tiff;

  toff_t
    *byte_count,
    strip_size;

  unsigned char
    *buffer;

  /*
    Write image as CCITT Group4 TIFF image to a temporary file.
  */
  assert(image_info != (const ImageInfo *) NULL);
  assert(image_info->signature == MagickCoreSignature);
  assert(image != (Image *) NULL);
  assert(image->signature == MagickCoreSignature);
  if (image->debug != MagickFalse)
    (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
  assert(exception != (ExceptionInfo *) NULL);
  assert(exception->signature == MagickCoreSignature);
  status=OpenBlob(image_info,image,WriteBinaryBlobMode,exception);
  if (status == MagickFalse)
    return(status);
  huffman_image=CloneImage(image,0,0,MagickTrue,exception);
  if (huffman_image == (Image *) NULL)
    {
      (void) CloseBlob(image);
      return(MagickFalse);
    }
  huffman_image->endian=MSBEndian;
  file=(FILE *) NULL;
  unique_file=AcquireUniqueFileResource(filename);
  if (unique_file != -1)
    file=fdopen(unique_file,"wb");
  if ((unique_file == -1) || (file == (FILE *) NULL))
    {
      ThrowFileException(exception,FileOpenError,"UnableToCreateTemporaryFile",
        filename);
      return(MagickFalse);
    }
  (void) FormatLocaleString(huffman_image->filename,MagickPathExtent,"tiff:%s",
    filename);
  if (IsImageMonochrome(image) == MagickFalse)
    (void) SetImageType(huffman_image,BilevelType,exception);
  write_info=CloneImageInfo((ImageInfo *) NULL);
  SetImageInfoFile(write_info,file);
  if (IsImageMonochrome(image) == MagickFalse)
    (void) SetImageType(image,BilevelType,exception);
  (void) SetImageDepth(image,1,exception);
  write_info->compression=Group4Compression;
  write_info->type=BilevelType;
  status=WriteTIFFImage(write_info,huffman_image,exception);
  (void) fflush(file);
  write_info=DestroyImageInfo(write_info);
  if (status == MagickFalse)
    {
      huffman_image=DestroyImage(huffman_image);
      (void) fclose(file);
      (void) RelinquishUniqueFileResource(filename);
      return(MagickFalse);
    }
  tiff=TIFFOpen(filename,"rb");
  if (tiff == (TIFF *) NULL)
    {
      huffman_image=DestroyImage(huffman_image);
      (void) fclose(file);
      (void) RelinquishUniqueFileResource(filename);
      ThrowFileException(exception,FileOpenError,"UnableToOpenFile",
        image_info->filename);
      return(MagickFalse);
    }
  /*
    Allocate raw strip buffer.
  */
  if (TIFFGetField(tiff,TIFFTAG_STRIPBYTECOUNTS,&byte_count) != 1)
    {
      TIFFClose(tiff);
      huffman_image=DestroyImage(huffman_image);
      (void) fclose(file);
      (void) RelinquishUniqueFileResource(filename);
      return(MagickFalse);
    }
  strip_size=byte_count[0];
  for (i=1; i < (ssize_t) TIFFNumberOfStrips(tiff); i++)
    if (byte_count[i] > strip_size)
      strip_size=byte_count[i];
  buffer=(unsigned char *) AcquireQuantumMemory((size_t) strip_size,
    sizeof(*buffer));
  if (buffer == (unsigned char *) NULL)
    {
      TIFFClose(tiff);
      huffman_image=DestroyImage(huffman_image);
      (void) fclose(file);
      (void) RelinquishUniqueFileResource(filename);
      ThrowBinaryException(ResourceLimitError,"MemoryAllocationFailed",
        image_info->filename);
    }
  /*
    Compress runlength encoded to 2D Huffman pixels.
  */
  for (i=0; i < (ssize_t) TIFFNumberOfStrips(tiff); i++)
  {
    count=(ssize_t) TIFFReadRawStrip(tiff,(uint32) i,buffer,strip_size);
    if (WriteBlob(image,(size_t) count,buffer) != count)
      status=MagickFalse;
  }
  buffer=(unsigned char *) RelinquishMagickMemory(buffer);
  TIFFClose(tiff);
  huffman_image=DestroyImage(huffman_image);
  (void) fclose(file);
  (void) RelinquishUniqueFileResource(filename);
  (void) CloseBlob(image);
  return(status);
}


static Image *ReadTIFFImage(const ImageInfo *image_info,
  ExceptionInfo *exception)
{
#define ThrowTIFFException(severity,message) \
{ \
  if (pixel_info != (MemoryInfo *) NULL) \
    pixel_info=RelinquishVirtualMemory(pixel_info); \
  if (quantum_info != (QuantumInfo *) NULL) \
    quantum_info=DestroyQuantumInfo(quantum_info); \
  TIFFClose(tiff); \
  ThrowReaderException(severity,message); \
}

  const char
    *option;

  float
    *chromaticity,
    x_position,
    y_position,
    x_resolution,
    y_resolution;

  Image
    *image;

  int
    tiff_status;

  MagickBooleanType
    more_frames,
    status;

  MagickSizeType
    number_pixels;

  MemoryInfo
    *pixel_info = (MemoryInfo *) NULL;

  QuantumInfo
    *quantum_info;

  QuantumType
    quantum_type;

  register ssize_t
    i;

  size_t
    pad;

  ssize_t
    y;

  TIFF
    *tiff;

  TIFFMethodType
    method;

  uint16
    compress_tag,
    bits_per_sample,
    endian,
    extra_samples,
    interlace,
    max_sample_value,
    min_sample_value,
    orientation,
    pages,
    photometric,
    *sample_info,
    sample_format,
    samples_per_pixel,
    units,
    value;

  uint32
    height,
    rows_per_strip,
    width;

  unsigned char
    *pixels;

  void
    *sans[2] = { NULL, NULL };

  /*
    Open image.
  */
  assert(image_info != (const ImageInfo *) NULL);
  assert(image_info->signature == MagickCoreSignature);
  if (image_info->debug != MagickFalse)
    (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",
      image_info->filename);
  assert(exception != (ExceptionInfo *) NULL);
  assert(exception->signature == MagickCoreSignature);
  image=AcquireImage(image_info,exception);
  status=OpenBlob(image_info,image,ReadBinaryBlobMode,exception);
  if (status == MagickFalse)
    {
      image=DestroyImageList(image);
      return((Image *) NULL);
    }
  (void) SetMagickThreadValue(tiff_exception,exception);
  tiff=TIFFClientOpen(image->filename,"rb",(thandle_t) image,TIFFReadBlob,
    TIFFWriteBlob,TIFFSeekBlob,TIFFCloseBlob,TIFFGetBlobSize,TIFFMapBlob,
    TIFFUnmapBlob);
  if (tiff == (TIFF *) NULL)
    {
      image=DestroyImageList(image);
      return((Image *) NULL);
    }
  if (exception->severity > ErrorException)
    {
      TIFFClose(tiff);
      image=DestroyImageList(image);
      return((Image *) NULL);
    }
  if (image_info->number_scenes != 0)
    {
      /*
        Generate blank images for subimage specification (e.g. image.tif[4].
        We need to check the number of directores because it is possible that
        the subimage(s) are stored in the photoshop profile.
      */
      if (image_info->scene < (size_t) TIFFNumberOfDirectories(tiff))
        {
          for (i=0; i < (ssize_t) image_info->scene; i++)
          {
            status=TIFFReadDirectory(tiff) != 0 ? MagickTrue : MagickFalse;
            if (status == MagickFalse)
              {
                TIFFClose(tiff);
                image=DestroyImageList(image);
                return((Image *) NULL);
              }
            AcquireNextImage(image_info,image,exception);
            if (GetNextImageInList(image) == (Image *) NULL)
              {
                TIFFClose(tiff);
                image=DestroyImageList(image);
                return((Image *) NULL);
              }
            image=SyncNextImageInList(image);
          }
      }
  }
  more_frames=MagickTrue;
  do
  {
    /* TIFFPrintDirectory(tiff,stdout,MagickFalse); */
    photometric=PHOTOMETRIC_RGB;
    if ((TIFFGetField(tiff,TIFFTAG_IMAGEWIDTH,&width) != 1) ||
        (TIFFGetField(tiff,TIFFTAG_IMAGELENGTH,&height) != 1) ||
        (TIFFGetFieldDefaulted(tiff,TIFFTAG_PHOTOMETRIC,&photometric,sans) != 1) ||
        (TIFFGetFieldDefaulted(tiff,TIFFTAG_COMPRESSION,&compress_tag,sans) != 1) ||
        (TIFFGetFieldDefaulted(tiff,TIFFTAG_FILLORDER,&endian,sans) != 1) ||
        (TIFFGetFieldDefaulted(tiff,TIFFTAG_PLANARCONFIG,&interlace,sans) != 1) ||
        (TIFFGetFieldDefaulted(tiff,TIFFTAG_SAMPLESPERPIXEL,&samples_per_pixel,sans) != 1) ||
        (TIFFGetFieldDefaulted(tiff,TIFFTAG_BITSPERSAMPLE,&bits_per_sample,sans) != 1) ||
        (TIFFGetFieldDefaulted(tiff,TIFFTAG_SAMPLEFORMAT,&sample_format,sans) != 1) ||
        (TIFFGetFieldDefaulted(tiff,TIFFTAG_MINSAMPLEVALUE,&min_sample_value,sans) != 1) ||
        (TIFFGetFieldDefaulted(tiff,TIFFTAG_MAXSAMPLEVALUE,&max_sample_value,sans) != 1))
      {
        TIFFClose(tiff);
        ThrowReaderException(CorruptImageError,"ImproperImageHeader");
      }
    if (((sample_format != SAMPLEFORMAT_IEEEFP) || (bits_per_sample != 64)) &&
        ((bits_per_sample <= 0) || (bits_per_sample > 32)))
      {
        TIFFClose(tiff);
        ThrowReaderException(CorruptImageError,"UnsupportedBitsPerPixel");
      }
    if (sample_format == SAMPLEFORMAT_IEEEFP)
      (void) SetImageProperty(image,"quantum:format","floating-point",
        exception);
    switch (photometric)
    {
      case PHOTOMETRIC_MINISBLACK:
      {
        (void) SetImageProperty(image,"tiff:photometric","min-is-black",
          exception);
        break;
      }
      case PHOTOMETRIC_MINISWHITE:
      {
        (void) SetImageProperty(image,"tiff:photometric","min-is-white",
          exception);
        break;
      }
      case PHOTOMETRIC_PALETTE:
      {
        (void) SetImageProperty(image,"tiff:photometric","palette",exception);
        break;
      }
      case PHOTOMETRIC_RGB:
      {
        (void) SetImageProperty(image,"tiff:photometric","RGB",exception);
        break;
      }
      case PHOTOMETRIC_CIELAB:
      {
        (void) SetImageProperty(image,"tiff:photometric","CIELAB",exception);
        break;
      }
      case PHOTOMETRIC_LOGL:
      {
        (void) SetImageProperty(image,"tiff:photometric","CIE Log2(L)",
          exception);
        break;
      }
      case PHOTOMETRIC_LOGLUV:
      {
        (void) SetImageProperty(image,"tiff:photometric","LOGLUV",exception);
        break;
      }
#if defined(PHOTOMETRIC_MASK)
      case PHOTOMETRIC_MASK:
      {
        (void) SetImageProperty(image,"tiff:photometric","MASK",exception);
        break;
      }
#endif
      case PHOTOMETRIC_SEPARATED:
      {
        (void) SetImageProperty(image,"tiff:photometric","separated",exception);
        break;
      }
      case PHOTOMETRIC_YCBCR:
      {
        (void) SetImageProperty(image,"tiff:photometric","YCBCR",exception);
        break;
      }
      default:
      {
        (void) SetImageProperty(image,"tiff:photometric","unknown",exception);
        break;
      }
    }
    if (image->debug != MagickFalse)
      {
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),"Geometry: %ux%u",
          (unsigned int) width,(unsigned int) height);
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),"Interlace: %u",
          interlace);
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "Bits per sample: %u",bits_per_sample);
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "Min sample value: %u",min_sample_value);
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "Max sample value: %u",max_sample_value);
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),"Photometric "
          "interpretation: %s",GetImageProperty(image,"tiff:photometric",
          exception));
      }
    image->columns=(size_t) width;
    image->rows=(size_t) height;
    image->depth=(size_t) bits_per_sample;
    if (image->debug != MagickFalse)
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),"Image depth: %.20g",
        (double) image->depth);
    image->endian=MSBEndian;
    if (endian == FILLORDER_LSB2MSB)
      image->endian=LSBEndian;
#if defined(MAGICKCORE_HAVE_TIFFISBIGENDIAN)
    if (TIFFIsBigEndian(tiff) == 0)
      {
        (void) SetImageProperty(image,"tiff:endian","lsb",exception);
        image->endian=LSBEndian;
      }
    else
      {
        (void) SetImageProperty(image,"tiff:endian","msb",exception);
        image->endian=MSBEndian;
      }
#endif
    if ((photometric == PHOTOMETRIC_MINISBLACK) ||
        (photometric == PHOTOMETRIC_MINISWHITE))
      image->colorspace=GRAYColorspace;
    if (photometric == PHOTOMETRIC_SEPARATED)
      image->colorspace=CMYKColorspace;
    if (photometric == PHOTOMETRIC_CIELAB)
      image->colorspace=LabColorspace;
    if ((photometric == PHOTOMETRIC_YCBCR) && (compress_tag != COMPRESSION_JPEG))
      image->colorspace=YCbCrColorspace;
    status=TIFFGetProfiles(tiff,image,exception);
    if (status == MagickFalse)
      {
        TIFFClose(tiff);
        return(DestroyImageList(image));
      }
    status=TIFFGetProperties(tiff,image,exception);
    if (status == MagickFalse)
      {
        TIFFClose(tiff);
        return(DestroyImageList(image));
      }
    option=GetImageOption(image_info,"tiff:exif-properties");
    if (IsStringFalse(option) == MagickFalse) /* enabled by default */
      TIFFGetEXIFProperties(tiff,image,exception);
    if ((TIFFGetFieldDefaulted(tiff,TIFFTAG_XRESOLUTION,&x_resolution,sans) == 1) &&
        (TIFFGetFieldDefaulted(tiff,TIFFTAG_YRESOLUTION,&y_resolution,sans) == 1))
      {
        image->resolution.x=x_resolution;
        image->resolution.y=y_resolution;
      }
    if (TIFFGetFieldDefaulted(tiff,TIFFTAG_RESOLUTIONUNIT,&units,sans,sans) == 1)
      {
        if (units == RESUNIT_INCH)
          image->units=PixelsPerInchResolution;
        if (units == RESUNIT_CENTIMETER)
          image->units=PixelsPerCentimeterResolution;
      }
    if ((TIFFGetFieldDefaulted(tiff,TIFFTAG_XPOSITION,&x_position,sans) == 1) &&
        (TIFFGetFieldDefaulted(tiff,TIFFTAG_YPOSITION,&y_position,sans) == 1))
      {
        image->page.x=(ssize_t) ceil(x_position*image->resolution.x-0.5);
        image->page.y=(ssize_t) ceil(y_position*image->resolution.y-0.5);
      }
    if (TIFFGetFieldDefaulted(tiff,TIFFTAG_ORIENTATION,&orientation,sans) == 1)
      image->orientation=(OrientationType) orientation;
    if (TIFFGetField(tiff,TIFFTAG_WHITEPOINT,&chromaticity) == 1)
      {
        if ((chromaticity != (float *) NULL) && (*chromaticity != 0.0))
          {
            image->chromaticity.white_point.x=chromaticity[0];
            image->chromaticity.white_point.y=chromaticity[1];
          }
      }
    if (TIFFGetField(tiff,TIFFTAG_PRIMARYCHROMATICITIES,&chromaticity) == 1)
      {
        if ((chromaticity != (float *) NULL) && (*chromaticity != 0.0))
          {
            image->chromaticity.red_primary.x=chromaticity[0];
            image->chromaticity.red_primary.y=chromaticity[1];
            image->chromaticity.green_primary.x=chromaticity[2];
            image->chromaticity.green_primary.y=chromaticity[3];
            image->chromaticity.blue_primary.x=chromaticity[4];
            image->chromaticity.blue_primary.y=chromaticity[5];
          }
      }
#if defined(MAGICKCORE_HAVE_TIFFISCODECCONFIGURED) || (TIFFLIB_VERSION > 20040919)
    if ((compress_tag != COMPRESSION_NONE) &&
        (TIFFIsCODECConfigured(compress_tag) == 0))
      {
        TIFFClose(tiff);
        ThrowReaderException(CoderError,"CompressNotSupported");
      }
#endif
    switch (compress_tag)
    {
      case COMPRESSION_NONE: image->compression=NoCompression; break;
      case COMPRESSION_CCITTFAX3: image->compression=FaxCompression; break;
      case COMPRESSION_CCITTFAX4: image->compression=Group4Compression; break;
      case COMPRESSION_JPEG:
      {
         image->compression=JPEGCompression;
#if defined(JPEG_SUPPORT)
         {
           char
             sampling_factor[MagickPathExtent];

           uint16
             horizontal,
             vertical;

           tiff_status=TIFFGetField(tiff,TIFFTAG_YCBCRSUBSAMPLING,&horizontal,
             &vertical);
           if (tiff_status == 1)
             {
               (void) FormatLocaleString(sampling_factor,MagickPathExtent,
                 "%dx%d",horizontal,vertical);
               (void) SetImageProperty(image,"jpeg:sampling-factor",
                 sampling_factor,exception);
               (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                 "Sampling Factors: %s",sampling_factor);
             }
         }
#endif
        break;
      }
      case COMPRESSION_OJPEG: image->compression=JPEGCompression; break;
#if defined(COMPRESSION_LZMA)
      case COMPRESSION_LZMA: image->compression=LZMACompression; break;
#endif
      case COMPRESSION_LZW: image->compression=LZWCompression; break;
      case COMPRESSION_DEFLATE: image->compression=ZipCompression; break;
      case COMPRESSION_ADOBE_DEFLATE: image->compression=ZipCompression; break;
#if defined(COMPRESSION_WEBP)
      case COMPRESSION_WEBP: image->compression=WebPCompression; break;
#endif
#if defined(COMPRESSION_ZSTD)
      case COMPRESSION_ZSTD: image->compression=ZstdCompression; break;
#endif
      default: image->compression=RLECompression; break;
    }
    quantum_info=(QuantumInfo *) NULL;
    if ((photometric == PHOTOMETRIC_PALETTE) &&
        (pow(2.0,1.0*bits_per_sample) <= MaxColormapSize))
      {
        size_t
          colors;

        colors=(size_t) GetQuantumRange(bits_per_sample)+1;
        if (AcquireImageColormap(image,colors,exception) == MagickFalse)
          {
            TIFFClose(tiff);
            ThrowReaderException(ResourceLimitError,"MemoryAllocationFailed");
          }
      }
    value=(unsigned short) image->scene;
    if (TIFFGetFieldDefaulted(tiff,TIFFTAG_PAGENUMBER,&value,&pages,sans) == 1)
      image->scene=value;
    if (image->storage_class == PseudoClass)
      {
        size_t
          range;

        uint16
          *blue_colormap,
          *green_colormap,
          *red_colormap;

        /*
          Initialize colormap.
        */
        tiff_status=TIFFGetField(tiff,TIFFTAG_COLORMAP,&red_colormap,
          &green_colormap,&blue_colormap);
        if (tiff_status == 1)
          {
            if ((red_colormap != (uint16 *) NULL) &&
                (green_colormap != (uint16 *) NULL) &&
                (blue_colormap != (uint16 *) NULL))
              {
                range=255;  /* might be old style 8-bit colormap */
                for (i=0; i < (ssize_t) image->colors; i++)
                  if ((red_colormap[i] >= 256) || (green_colormap[i] >= 256) ||
                      (blue_colormap[i] >= 256))
                    {
                      range=65535;
                      break;
                    }
                for (i=0; i < (ssize_t) image->colors; i++)
                {
                  image->colormap[i].red=ClampToQuantum(((double)
                    QuantumRange*red_colormap[i])/range);
                  image->colormap[i].green=ClampToQuantum(((double)
                    QuantumRange*green_colormap[i])/range);
                  image->colormap[i].blue=ClampToQuantum(((double)
                    QuantumRange*blue_colormap[i])/range);
                }
              }
          }
      }
    if (image_info->ping != MagickFalse)
      {
        if (image_info->number_scenes != 0)
          if (image->scene >= (image_info->scene+image_info->number_scenes-1))
            break;
        goto next_tiff_frame;
      }
    status=SetImageExtent(image,image->columns,image->rows,exception);
    if (status == MagickFalse)
      {
        TIFFClose(tiff);
        return(DestroyImageList(image));
      }
    status=SetImageColorspace(image,image->colorspace,exception);
    status&=ResetImagePixels(image,exception);
    if (status == MagickFalse)
      {
        TIFFClose(tiff);
        return(DestroyImageList(image));
      }
    /*
      Allocate memory for the image and pixel buffer.
    */
    quantum_info=AcquireQuantumInfo(image_info,image);
    if (quantum_info == (QuantumInfo *) NULL)
      ThrowTIFFException(ResourceLimitError,"MemoryAllocationFailed");
    if (sample_format == SAMPLEFORMAT_UINT)
      status=SetQuantumFormat(image,quantum_info,UnsignedQuantumFormat);
    if (sample_format == SAMPLEFORMAT_INT)
      status=SetQuantumFormat(image,quantum_info,SignedQuantumFormat);
    if (sample_format == SAMPLEFORMAT_IEEEFP)
      status=SetQuantumFormat(image,quantum_info,FloatingPointQuantumFormat);
    if (status == MagickFalse)
      ThrowTIFFException(ResourceLimitError,"MemoryAllocationFailed");
    status=MagickTrue;
    switch (photometric)
    {
      case PHOTOMETRIC_MINISBLACK:
      {
        quantum_info->min_is_white=MagickFalse;
        break;
      }
      case PHOTOMETRIC_MINISWHITE:
      {
        quantum_info->min_is_white=MagickTrue;
        break;
      }
      default:
        break;
    }
    extra_samples=0;
    tiff_status=TIFFGetFieldDefaulted(tiff,TIFFTAG_EXTRASAMPLES,&extra_samples,
      &sample_info,sans);
    if (tiff_status == 1)
      {
        (void) SetImageProperty(image,"tiff:alpha","unspecified",exception);
        if (extra_samples == 0)
          {
            if ((samples_per_pixel == 4) && (photometric == PHOTOMETRIC_RGB))
              image->alpha_trait=BlendPixelTrait;
          }
        else
          for (i=0; i < extra_samples; i++)
          {
            image->alpha_trait=BlendPixelTrait;
            if (sample_info[i] == EXTRASAMPLE_ASSOCALPHA)
              {
                SetQuantumAlphaType(quantum_info,AssociatedQuantumAlpha);
                (void) SetImageProperty(image,"tiff:alpha","associated",
                  exception);
              }
            else
              if (sample_info[i] == EXTRASAMPLE_UNASSALPHA)
                {
                  SetQuantumAlphaType(quantum_info,DisassociatedQuantumAlpha);
                  (void) SetImageProperty(image,"tiff:alpha","unassociated",
                    exception);
                }
          }
      }
    if (image->alpha_trait != UndefinedPixelTrait)
      (void) SetImageAlphaChannel(image,OpaqueAlphaChannel,exception);
    if (samples_per_pixel > MaxPixelChannels)
      {
        TIFFClose(tiff);
        ThrowReaderException(CorruptImageError,"MaximumChannelsExceeded");
      }
    method=ReadGenericMethod;
    rows_per_strip=(uint32) image->rows;
    if (TIFFGetField(tiff,TIFFTAG_ROWSPERSTRIP,&rows_per_strip) == 1)
      {
        char
          buffer[MagickPathExtent];

        (void) FormatLocaleString(buffer,MagickPathExtent,"%u",
          (unsigned int) rows_per_strip);
        (void) SetImageProperty(image,"tiff:rows-per-strip",buffer,exception);
        method=ReadStripMethod;
        if (rows_per_strip > (uint32) image->rows)
          rows_per_strip=(uint32) image->rows;
      }
    if (TIFFIsTiled(tiff) != MagickFalse)
      {
        uint32
          columns,
          rows;

        if ((TIFFGetField(tiff,TIFFTAG_TILEWIDTH,&columns) != 1) ||
            (TIFFGetField(tiff,TIFFTAG_TILELENGTH,&rows) != 1))
          ThrowTIFFException(CoderError,"ImageIsNotTiled");
        if ((AcquireMagickResource(WidthResource,columns) == MagickFalse) ||
            (AcquireMagickResource(HeightResource,rows) == MagickFalse))
          ThrowTIFFException(ImageError,"WidthOrHeightExceedsLimit");
        method=ReadTileMethod;
      }
    if (image->compression == JPEGCompression)
      method=GetJPEGMethod(image,tiff,photometric,bits_per_sample,
        samples_per_pixel);
    if (photometric == PHOTOMETRIC_LOGLUV)
      method=ReadGenericMethod;
    quantum_info->endian=LSBEndian;
    quantum_type=RGBQuantum;
    if (TIFFScanlineSize(tiff) <= 0)
      ThrowTIFFException(ResourceLimitError,"MemoryAllocationFailed");
    if ((1.0*TIFFScanlineSize(tiff)) > (2.53*GetBlobSize(image)))
      ThrowTIFFException(CorruptImageError,"InsufficientImageDataInFile");
    number_pixels=MagickMax(TIFFScanlineSize(tiff),MagickMax((ssize_t)
      image->columns*samples_per_pixel*pow(2.0,ceil(log(bits_per_sample)/
      log(2.0))),image->columns*rows_per_strip));
    pixel_info=AcquireVirtualMemory(number_pixels,sizeof(uint32));
    if (pixel_info == (MemoryInfo *) NULL)
      ThrowTIFFException(ResourceLimitError,"MemoryAllocationFailed");
    pixels=(unsigned char *) GetVirtualMemoryBlob(pixel_info);
    (void) memset(pixels,0,number_pixels*sizeof(uint32));
    quantum_type=IndexQuantum;
    pad=(size_t) MagickMax((ssize_t) samples_per_pixel-1,0);
    if (image->alpha_trait != UndefinedPixelTrait)
      {
        if (image->storage_class == PseudoClass)
          quantum_type=IndexAlphaQuantum;
        else
          quantum_type=samples_per_pixel == 1 ? AlphaQuantum : GrayAlphaQuantum;
      }
    else
      if (image->storage_class != PseudoClass)
        quantum_type=GrayQuantum;
    if ((samples_per_pixel > 2) && (interlace != PLANARCONFIG_SEPARATE))
      {
        pad=(size_t) MagickMax((size_t) samples_per_pixel-3,0);
        quantum_type=RGBQuantum;
        if (image->alpha_trait != UndefinedPixelTrait)
          {
            quantum_type=RGBAQuantum;
            pad=(size_t) MagickMax((size_t) samples_per_pixel-4,0);
          }
        if (image->colorspace == CMYKColorspace)
          {
            pad=(size_t) MagickMax((size_t) samples_per_pixel-4,0);
            quantum_type=CMYKQuantum;
            if (image->alpha_trait != UndefinedPixelTrait)
              {
                quantum_type=CMYKAQuantum;
                pad=(size_t) MagickMax((size_t) samples_per_pixel-5,0);
              }
          }
        status=SetQuantumPad(image,quantum_info,pad*((bits_per_sample+7) >> 3));
        if (status == MagickFalse)
          ThrowTIFFException(ResourceLimitError,"MemoryAllocationFailed");
      }
    switch (method)
    {
      case ReadYCCKMethod:
      {
        /*
          Convert YCC TIFF image.
        */
        for (y=0; y < (ssize_t) image->rows; y++)
        {
          register Quantum
            *magick_restrict q;

          register ssize_t
            x;

          unsigned char
            *p;

          tiff_status=TIFFReadPixels(tiff,0,y,(char *) pixels);
          if (tiff_status == -1)
            break;
          q=QueueAuthenticPixels(image,0,y,image->columns,1,exception);
          if (q == (Quantum *) NULL)
            break;
          p=pixels;
          for (x=0; x < (ssize_t) image->columns; x++)
          {
            SetPixelCyan(image,ScaleCharToQuantum(ClampYCC((double) *p+
              (1.402*(double) *(p+2))-179.456)),q);
            SetPixelMagenta(image,ScaleCharToQuantum(ClampYCC((double) *p-
              (0.34414*(double) *(p+1))-(0.71414*(double ) *(p+2))+
              135.45984)),q);
            SetPixelYellow(image,ScaleCharToQuantum(ClampYCC((double) *p+
              (1.772*(double) *(p+1))-226.816)),q);
            SetPixelBlack(image,ScaleCharToQuantum((unsigned char) *(p+3)),q);
            q+=GetPixelChannels(image);
            p+=4;
          }
          if (SyncAuthenticPixels(image,exception) == MagickFalse)
            break;
          if (image->previous == (Image *) NULL)
            {
              status=SetImageProgress(image,LoadImageTag,(MagickOffsetType) y,
                image->rows);
              if (status == MagickFalse)
                break;
            }
        }
        break;
      }
      case ReadStripMethod:
      {
        register unsigned char
          *p;

        size_t
          extent;

        ssize_t
          stride,
          strip_id;

        tsize_t
          strip_size;

        unsigned char
          *strip_pixels;

        /*
          Convert stripped TIFF image.
        */
        extent=TIFFStripSize(tiff);
#if defined(TIFF_VERSION_BIG)
        extent+=image->columns*sizeof(uint64);
#else
        extent+=image->columns*sizeof(uint32);
#endif
        strip_pixels=(unsigned char *) AcquireQuantumMemory(extent,
          2*sizeof(*strip_pixels));
        if (strip_pixels == (unsigned char *) NULL)
          ThrowTIFFException(ResourceLimitError,"MemoryAllocationFailed");
        (void) memset(strip_pixels,0,extent*sizeof(*strip_pixels));
        stride=TIFFVStripSize(tiff,1);
        strip_id=0;
        p=strip_pixels;
        for (i=0; i < (ssize_t) samples_per_pixel; i++)
        {
          size_t
            rows_remaining;

          switch (i)
          {
            case 0: break;
            case 1: quantum_type=GreenQuantum; break;
            case 2: quantum_type=BlueQuantum; break;
            case 3:
            {
              if (image->colorspace == CMYKColorspace)
                quantum_type=BlackQuantum;
              break;
            }
            case 4: quantum_type=AlphaQuantum; break;
          }
          rows_remaining=0;
          for (y=0; y < (ssize_t) image->rows; y++)
          {
            register Quantum
              *magick_restrict q;

            q=GetAuthenticPixels(image,0,y,image->columns,1,exception);
            if (q == (Quantum *) NULL)
              break;
            if (rows_remaining == 0)
              {
                strip_size=TIFFReadEncodedStrip(tiff,strip_id,strip_pixels,
                  TIFFStripSize(tiff));
                if (strip_size == -1)
                  break;
                rows_remaining=rows_per_strip;
                if ((y+rows_per_strip) > image->rows)
                  rows_remaining=(rows_per_strip-(y+rows_per_strip-
                    image->rows));
                p=strip_pixels;
                strip_id++;
              }
            (void) ImportQuantumPixels(image,(CacheView *) NULL,
              quantum_info,quantum_type,p,exception);
            p+=stride;
            rows_remaining--;
            if (SyncAuthenticPixels(image,exception) == MagickFalse)
              break;
            if (image->previous == (Image *) NULL)
              {
                status=SetImageProgress(image,LoadImageTag,(MagickOffsetType) y,
                  image->rows);
                if (status == MagickFalse)
                  break;
              }
          }
          if ((samples_per_pixel > 1) && (interlace != PLANARCONFIG_SEPARATE))
            break;
        }
        strip_pixels=(unsigned char *) RelinquishMagickMemory(strip_pixels);
        break;
      }
      case ReadTileMethod:
      {
        register unsigned char
          *p;

        size_t
          extent;

        uint32
          columns,
          rows;

        unsigned char
          *tile_pixels;

        /*
          Convert tiled TIFF image.
        */
        if ((TIFFGetField(tiff,TIFFTAG_TILEWIDTH,&columns) != 1) ||
            (TIFFGetField(tiff,TIFFTAG_TILELENGTH,&rows) != 1))
          ThrowTIFFException(CoderError,"ImageIsNotTiled");
        number_pixels=(MagickSizeType) columns*rows;
        if (HeapOverflowSanityCheck(rows,sizeof(*tile_pixels)) != MagickFalse)
          ThrowTIFFException(ResourceLimitError,"MemoryAllocationFailed");
        extent=TIFFTileSize(tiff);
#if defined(TIFF_VERSION_BIG)
        extent+=columns*sizeof(uint64);
#else
        extent+=columns*sizeof(uint32);
#endif
        tile_pixels=(unsigned char *) AcquireQuantumMemory(extent,
          sizeof(*tile_pixels));
        if (tile_pixels == (unsigned char *) NULL)
          ThrowTIFFException(ResourceLimitError,"MemoryAllocationFailed");
        (void) memset(tile_pixels,0,extent*sizeof(*tile_pixels));
        for (i=0; i < (ssize_t) samples_per_pixel; i++)
        {
          switch (i)
          {
            case 0: break;
            case 1: quantum_type=GreenQuantum; break;
            case 2: quantum_type=BlueQuantum; break;
            case 3:
            {
              if (image->colorspace == CMYKColorspace)
                quantum_type=BlackQuantum;
              break;
            }
            case 4: quantum_type=AlphaQuantum; break;
          }
          for (y=0; y < (ssize_t) image->rows; y+=rows)
          {
            register ssize_t
              x;

            size_t
              rows_remaining;

            rows_remaining=image->rows-y;
            if ((ssize_t) (y+rows) < (ssize_t) image->rows)
              rows_remaining=rows;
            for (x=0; x < (ssize_t) image->columns; x+=columns)
            {
              size_t
                columns_remaining,
                row;

              columns_remaining=image->columns-x;
              if ((ssize_t) (x+columns) < (ssize_t) image->columns)
                columns_remaining=columns;
              if (TIFFReadTile(tiff,tile_pixels,(uint32) x,(uint32) y,0,i) == 0)
                break;
              p=tile_pixels;
              for (row=0; row < rows_remaining; row++)
              {
                register Quantum
                  *magick_restrict q;

                q=GetAuthenticPixels(image,x,y+row,columns_remaining,1,
                  exception);
                if (q == (Quantum *) NULL)
                  break;
                (void) ImportQuantumPixels(image,(CacheView *) NULL,
                  quantum_info,quantum_type,p,exception);
                p+=TIFFTileRowSize(tiff);
                if (SyncAuthenticPixels(image,exception) == MagickFalse)
                  break;
              }
            }
          }
          if ((samples_per_pixel > 1) && (interlace != PLANARCONFIG_SEPARATE))
            break;
          if (image->previous == (Image *) NULL)
            {
              status=SetImageProgress(image,LoadImageTag,(MagickOffsetType) i,
                samples_per_pixel);
              if (status == MagickFalse)
                break;
            }
        }
        tile_pixels=(unsigned char *) RelinquishMagickMemory(tile_pixels);
        break;
      }
      case ReadGenericMethod:
      default:
      {
        MemoryInfo
          *generic_info = (MemoryInfo * ) NULL;

        register uint32
          *p;

        uint32
          *pixels;

        /*
          Convert generic TIFF image.
        */
        if (HeapOverflowSanityCheck(image->rows,sizeof(*pixels)) != MagickFalse)
          ThrowTIFFException(ResourceLimitError,"MemoryAllocationFailed");
        number_pixels=(MagickSizeType) image->columns*image->rows;
        number_pixels+=image->columns*sizeof(uint32);
        generic_info=AcquireVirtualMemory(number_pixels,sizeof(uint32));
        if (generic_info == (MemoryInfo *) NULL)
          ThrowTIFFException(ResourceLimitError,"MemoryAllocationFailed");
        pixels=(uint32 *) GetVirtualMemoryBlob(generic_info);
        (void) TIFFReadRGBAImage(tiff,(uint32) image->columns,(uint32)
          image->rows,(uint32 *) pixels,0);
        p=pixels+(image->columns*image->rows)-1;
        for (y=0; y < (ssize_t) image->rows; y++)
        {
          register ssize_t
            x;

          register Quantum
            *magick_restrict q;

          q=QueueAuthenticPixels(image,0,y,image->columns,1,exception);
          if (q == (Quantum *) NULL)
            break;
          q+=GetPixelChannels(image)*(image->columns-1);
          for (x=0; x < (ssize_t) image->columns; x++)
          {
            SetPixelRed(image,ScaleCharToQuantum((unsigned char)
              TIFFGetR(*p)),q);
            SetPixelGreen(image,ScaleCharToQuantum((unsigned char)
              TIFFGetG(*p)),q);
            SetPixelBlue(image,ScaleCharToQuantum((unsigned char)
              TIFFGetB(*p)),q);
            if (image->alpha_trait != UndefinedPixelTrait)
              SetPixelAlpha(image,ScaleCharToQuantum((unsigned char)
                TIFFGetA(*p)),q);
            p--;
            q-=GetPixelChannels(image);
          }
          if (SyncAuthenticPixels(image,exception) == MagickFalse)
            break;
          if (image->previous == (Image *) NULL)
            {
              status=SetImageProgress(image,LoadImageTag,(MagickOffsetType) y,
                image->rows);
              if (status == MagickFalse)
                break;
            }
        }
        generic_info=RelinquishVirtualMemory(generic_info);
        break;
      }
    }
    pixel_info=RelinquishVirtualMemory(pixel_info);
    SetQuantumImageType(image,quantum_type);
  next_tiff_frame:
    if (quantum_info != (QuantumInfo *) NULL)
      quantum_info=DestroyQuantumInfo(quantum_info);
    if (photometric == PHOTOMETRIC_CIELAB)
      DecodeLabImage(image,exception);
    if ((photometric == PHOTOMETRIC_LOGL) ||
        (photometric == PHOTOMETRIC_MINISBLACK) ||
        (photometric == PHOTOMETRIC_MINISWHITE))
      {
        image->type=GrayscaleType;
        if (bits_per_sample == 1)
          image->type=BilevelType;
      }
    /*
      Proceed to next image.
    */
    if (image_info->number_scenes != 0)
      if (image->scene >= (image_info->scene+image_info->number_scenes-1))
        break;
    more_frames=TIFFReadDirectory(tiff) != 0 ? MagickTrue : MagickFalse;
    if (more_frames != MagickFalse)
      {
        /*
          Allocate next image structure.
        */
        AcquireNextImage(image_info,image,exception);
        if (GetNextImageInList(image) == (Image *) NULL)
          {
            status=MagickFalse;
            break;
          }
        image=SyncNextImageInList(image);
        status=SetImageProgress(image,LoadImagesTag,image->scene-1,
          image->scene);
        if (status == MagickFalse)
          break;
      }
  } while ((status != MagickFalse) && (more_frames != MagickFalse));
  TIFFClose(tiff);
  if (status != MagickFalse)
    TIFFReadPhotoshopLayers(image_info,image,exception);
  if ((image_info->number_scenes != 0) &&
      (image_info->scene >= GetImageListLength(image)))
    status=MagickFalse;
  if (status == MagickFalse)
    return(DestroyImageList(image));
  return(GetFirstImageInList(image));
}


static TIFFMethodType GetJPEGMethod(Image* image,TIFF *tiff,uint16 photometric,
  uint16 bits_per_sample,uint16 samples_per_pixel)
{
#define BUFFER_SIZE 2048

  MagickOffsetType
    position,
    offset;

  register size_t
    i;

  TIFFMethodType
    method;

#if defined(TIFF_VERSION_BIG)
  uint64
#else
  uint32
#endif
    *value;

  unsigned char
    buffer[BUFFER_SIZE+32];

  unsigned short
    length;

  /*
    Only support 8 bit for now.
  */
  if ((photometric != PHOTOMETRIC_SEPARATED) || (bits_per_sample != 8) ||
      (samples_per_pixel != 4))
    return(ReadGenericMethod);
  /*
    Search for Adobe APP14 JPEG marker.
  */
  value=NULL;
  if (!TIFFGetField(tiff,TIFFTAG_STRIPOFFSETS,&value) || (value == NULL))
    return(ReadStripMethod);
  position=TellBlob(image);
  offset=(MagickOffsetType) (value[0]);
  if (SeekBlob(image,offset,SEEK_SET) != offset)
    return(ReadStripMethod);
  method=ReadStripMethod;
  if (ReadBlob(image,BUFFER_SIZE,buffer) == BUFFER_SIZE)
    {
      for (i=0; i < BUFFER_SIZE; i++)
      {
        while (i < BUFFER_SIZE)
        {
          if (buffer[i++] == 255)
           break;
        }
        while (i < BUFFER_SIZE)
        {
          if (buffer[++i] != 255)
           break;
        }
        if (buffer[i++] == 216) /* JPEG_MARKER_SOI */
          continue;
        length=(unsigned short) (((unsigned int) (buffer[i] << 8) |
          (unsigned int) buffer[i+1]) & 0xffff);
        if (i+(size_t) length >= BUFFER_SIZE)
          break;
        if (buffer[i-1] == 238) /* JPEG_MARKER_APP0+14 */
          {
            if (length != 14)
              break;
            /* 0 == CMYK, 1 == YCbCr, 2 = YCCK */
            if (buffer[i+13] == 2)
              method=ReadYCCKMethod;
            break;
          }
        i+=(size_t) length;
      }
    }
  (void) SeekBlob(image,position,SEEK_SET);
  return(method);
}


static int oidc_delete_oldest_state_cookies(request_rec *r,
		int number_of_valid_state_cookies, int max_number_of_state_cookies,
		oidc_state_cookies_t *first) {
	oidc_state_cookies_t *cur = NULL, *prev = NULL, *prev_oldest = NULL,
			*oldest = NULL;
	while (number_of_valid_state_cookies >= max_number_of_state_cookies) {
		oldest = first;
		prev_oldest = NULL;
		prev = first;
		cur = first->next;
		while (cur) {
			if ((cur->timestamp < oldest->timestamp)) {
				oldest = cur;
				prev_oldest = prev;
			}
			prev = cur;
			cur = cur->next;
		}
		oidc_warn(r,
				"deleting oldest state cookie: %s (time until expiry %" APR_TIME_T_FMT " seconds)",
				oldest->name, apr_time_sec(oldest->timestamp - apr_time_now()));
		oidc_util_set_cookie(r, oldest->name, "", 0, NULL);
		if (prev_oldest)
			prev_oldest->next = oldest->next;
		else
			first = first->next;
		number_of_valid_state_cookies--;
	}
	return number_of_valid_state_cookies;
}

2.4.0.2 oops

Signed-off-by: Hans Zandbelt <hans.zandbelt@zmartzone.eu>


static void oidc_scrub_request_headers(request_rec *r, const char *claim_prefix,
		apr_hash_t *scrub) {

	const int prefix_len = claim_prefix ? strlen(claim_prefix) : 0;

	/* get an array representation of the incoming HTTP headers */
	const apr_array_header_t * const h = apr_table_elts(r->headers_in);

	/* table to keep the non-suspicious headers */
	apr_table_t *clean_headers = apr_table_make(r->pool, h->nelts);

	/* loop over the incoming HTTP headers */
	const apr_table_entry_t * const e = (const apr_table_entry_t *) h->elts;
	int i;
	for (i = 0; i < h->nelts; i++) {
		const char * const k = e[i].key;

		/* is this header's name equivalent to a header that needs scrubbing? */
		const char *hdr =
				(k != NULL) && (scrub != NULL) ?
						apr_hash_get(scrub, k, APR_HASH_KEY_STRING) : NULL;
		const int header_matches = (hdr != NULL)
						&& (oidc_strnenvcmp(k, hdr, -1) == 0);

		/*
		 * would this header be interpreted as a mod_auth_openidc attribute? Note
		 * that prefix_len will be zero if no attr_prefix is defined,
		 * so this will always be false. Also note that we do not
		 * scrub headers if the prefix is empty because every header
		 * would match.
		 */
		const int prefix_matches = (k != NULL) && prefix_len
				&& (oidc_strnenvcmp(k, claim_prefix, prefix_len) == 0);

		/* add to the clean_headers if non-suspicious, skip and report otherwise */
		if (!prefix_matches && !header_matches) {
			apr_table_addn(clean_headers, k, e[i].val);
		} else {
			oidc_warn(r, "scrubbed suspicious request header (%s: %.32s)", k,
					e[i].val);
		}
	}

	/* overwrite the incoming headers with the cleaned result */
	r->headers_in = clean_headers;
}


static int oidc_handle_logout(request_rec *r, oidc_cfg *c,
		oidc_session_t *session) {

	oidc_provider_t *provider = NULL;
	/* pickup the command or URL where the user wants to go after logout */
	char *url = NULL;
	char *error_str = NULL;
	char *error_description = NULL;

	oidc_util_get_request_parameter(r, OIDC_REDIRECT_URI_REQUEST_LOGOUT, &url);

	oidc_debug(r, "enter (url=%s)", url);

	if (oidc_is_front_channel_logout(url)) {
		return oidc_handle_logout_request(r, c, session, url);
	} else if (oidc_is_back_channel_logout(url)) {
		return oidc_handle_logout_backchannel(r, c);
	}

	if ((url == NULL) || (apr_strnatcmp(url, "") == 0)) {

		url = c->default_slo_url;

	} else {

		/* do input validation on the logout parameter value */
		if (oidc_validate_post_logout_url(r, url, &error_str,
				&error_description) == FALSE) {
			return oidc_util_html_send_error(r, c->error_template, error_str,
					error_description,
					HTTP_BAD_REQUEST);
		}
	}

	oidc_get_provider_from_session(r, c, session, &provider);

	if ((provider != NULL) && (provider->end_session_endpoint != NULL)) {

		const char *id_token_hint = oidc_session_get_idtoken(r, session);

		char *logout_request = apr_pstrdup(r->pool,
				provider->end_session_endpoint);
		if (id_token_hint != NULL) {
			logout_request = apr_psprintf(r->pool, "%s%sid_token_hint=%s",
					logout_request, strchr(logout_request ? logout_request : "",
							OIDC_CHAR_QUERY) != NULL ?
									OIDC_STR_AMP :
									OIDC_STR_QUERY,
									oidc_util_escape_string(r, id_token_hint));
		}

		if (url != NULL) {
			logout_request = apr_psprintf(r->pool,
					"%s%spost_logout_redirect_uri=%s", logout_request,
					strchr(logout_request ? logout_request : "",
							OIDC_CHAR_QUERY) != NULL ?
									OIDC_STR_AMP :
									OIDC_STR_QUERY,
									oidc_util_escape_string(r, url));
		}
		url = logout_request;
	}

	return oidc_handle_logout_request(r, c, session, url);
}


static int oidc_handle_discovery_response(request_rec *r, oidc_cfg *c) {

	/* variables to hold the values returned in the response */
	char *issuer = NULL, *target_link_uri = NULL, *login_hint = NULL,
			*auth_request_params = NULL, *csrf_cookie, *csrf_query = NULL,
			*user = NULL, *path_scopes;
	oidc_provider_t *provider = NULL;

	oidc_util_get_request_parameter(r, OIDC_DISC_OP_PARAM, &issuer);
	oidc_util_get_request_parameter(r, OIDC_DISC_USER_PARAM, &user);
	oidc_util_get_request_parameter(r, OIDC_DISC_RT_PARAM, &target_link_uri);
	oidc_util_get_request_parameter(r, OIDC_DISC_LH_PARAM, &login_hint);
	oidc_util_get_request_parameter(r, OIDC_DISC_SC_PARAM, &path_scopes);
	oidc_util_get_request_parameter(r, OIDC_DISC_AR_PARAM,
			&auth_request_params);
	oidc_util_get_request_parameter(r, OIDC_CSRF_NAME, &csrf_query);
	csrf_cookie = oidc_util_get_cookie(r, OIDC_CSRF_NAME);

	/* do CSRF protection if not 3rd party initiated SSO */
	if (csrf_cookie) {

		/* clean CSRF cookie */
		oidc_util_set_cookie(r, OIDC_CSRF_NAME, "", 0, NULL);

		/* compare CSRF cookie value with query parameter value */
		if ((csrf_query == NULL)
				|| apr_strnatcmp(csrf_query, csrf_cookie) != 0) {
			oidc_warn(r,
					"CSRF protection failed, no Discovery and dynamic client registration will be allowed");
			csrf_cookie = NULL;
		}
	}

	// TODO: trim issuer/accountname/domain input and do more input validation

	oidc_debug(r,
			"issuer=\"%s\", target_link_uri=\"%s\", login_hint=\"%s\", user=\"%s\"",
			issuer, target_link_uri, login_hint, user);

	if (target_link_uri == NULL) {
		if (c->default_sso_url == NULL) {
			return oidc_util_html_send_error(r, c->error_template,
					"Invalid Request",
					"SSO to this module without specifying a \"target_link_uri\" parameter is not possible because " OIDCDefaultURL " is not set.",
					HTTP_INTERNAL_SERVER_ERROR);
		}
		target_link_uri = c->default_sso_url;
	}

	/* do open redirect prevention */
	if (oidc_target_link_uri_matches_configuration(r, c,
			target_link_uri) == FALSE) {
		return oidc_util_html_send_error(r, c->error_template,
				"Invalid Request",
				"\"target_link_uri\" parameter does not match configuration settings, aborting to prevent an open redirect.",
				HTTP_UNAUTHORIZED);
	}

	/* see if this is a static setup */
	if (c->metadata_dir == NULL) {
		if ((oidc_provider_static_config(r, c, &provider) == TRUE)
				&& (issuer != NULL)) {
			if (apr_strnatcmp(provider->issuer, issuer) != 0) {
				return oidc_util_html_send_error(r, c->error_template,
						"Invalid Request",
						apr_psprintf(r->pool,
								"The \"iss\" value must match the configured providers' one (%s != %s).",
								issuer, c->provider.issuer),
								HTTP_INTERNAL_SERVER_ERROR);
			}
		}
		return oidc_authenticate_user(r, c, NULL, target_link_uri, login_hint,
				NULL, NULL, auth_request_params, path_scopes);
	}

	/* find out if the user entered an account name or selected an OP manually */
	if (user != NULL) {

		if (login_hint == NULL)
			login_hint = apr_pstrdup(r->pool, user);

		/* normalize the user identifier */
		if (strstr(user, "https://") != user)
			user = apr_psprintf(r->pool, "https://%s", user);

		/* got an user identifier as input, perform OP discovery with that */
		if (oidc_proto_url_based_discovery(r, c, user, &issuer) == FALSE) {

			/* something did not work out, show a user facing error */
			return oidc_util_html_send_error(r, c->error_template,
					"Invalid Request",
					"Could not resolve the provided user identifier to an OpenID Connect provider; check your syntax.",
					HTTP_NOT_FOUND);
		}

		/* issuer is set now, so let's continue as planned */

	} else if (strstr(issuer, OIDC_STR_AT) != NULL) {

		if (login_hint == NULL) {
			login_hint = apr_pstrdup(r->pool, issuer);
			//char *p = strstr(issuer, OIDC_STR_AT);
			//*p = '\0';
		}

		/* got an account name as input, perform OP discovery with that */
		if (oidc_proto_account_based_discovery(r, c, issuer, &issuer) == FALSE) {

			/* something did not work out, show a user facing error */
			return oidc_util_html_send_error(r, c->error_template,
					"Invalid Request",
					"Could not resolve the provided account name to an OpenID Connect provider; check your syntax.",
					HTTP_NOT_FOUND);
		}

		/* issuer is set now, so let's continue as planned */

	}

	/* strip trailing '/' */
	int n = strlen(issuer);
	if (issuer[n - 1] == OIDC_CHAR_FORWARD_SLASH)
		issuer[n - 1] = '\0';

	/* try and get metadata from the metadata directories for the selected OP */
	if ((oidc_metadata_get(r, c, issuer, &provider, csrf_cookie != NULL) == TRUE)
			&& (provider != NULL)) {

		/* now we've got a selected OP, send the user there to authenticate */
		return oidc_authenticate_user(r, c, provider, target_link_uri,
				login_hint, NULL, NULL, auth_request_params, path_scopes);
	}

	/* something went wrong */
	return oidc_util_html_send_error(r, c->error_template, "Invalid Request",
			"Could not find valid provider metadata for the selected OpenID Connect provider; contact the administrator",
			HTTP_NOT_FOUND);
}


static char *oidc_get_state_cookie_name(request_rec *r, const char *state) {
	return apr_psprintf(r->pool, "%s%s", OIDC_STATE_COOKIE_PREFIX, state);
}


apr_byte_t oidc_enabled(request_rec *r) {
	if (ap_auth_type(r) == NULL)
		return FALSE;

	if (apr_strnatcasecmp((const char *) ap_auth_type(r),
			OIDC_AUTH_TYPE_OPENID_CONNECT) == 0)
		return TRUE;

	if (apr_strnatcasecmp((const char *) ap_auth_type(r),
			OIDC_AUTH_TYPE_OPENID_OAUTH20) == 0)
		return TRUE;

	if (apr_strnatcasecmp((const char *) ap_auth_type(r),
			OIDC_AUTH_TYPE_OPENID_BOTH) == 0)
		return TRUE;

	return FALSE;
}


static int oidc_handle_existing_session(request_rec *r, oidc_cfg *cfg,
		oidc_session_t *session) {

	oidc_debug(r, "enter");

	/* track if the session needs to be updated/saved into the cache */
	apr_byte_t needs_save = FALSE;

	/* set the user in the main request for further (incl. sub-request) processing */
	r->user = apr_pstrdup(r->pool, session->remote_user);
	oidc_debug(r, "set remote_user to \"%s\"", r->user);

	/* get the header name in which the remote user name needs to be passed */
	char *authn_header = oidc_cfg_dir_authn_header(r);
	apr_byte_t pass_headers = oidc_cfg_dir_pass_info_in_headers(r);
	apr_byte_t pass_envvars = oidc_cfg_dir_pass_info_in_envvars(r);

	/* verify current cookie domain against issued cookie domain */
	if (oidc_check_cookie_domain(r, cfg, session) == FALSE)
		return HTTP_UNAUTHORIZED;

	/* check if the maximum session duration was exceeded */
	int rc = oidc_check_max_session_duration(r, cfg, session);
	if (rc != OK)
		return rc;

	/* if needed, refresh the access token */
	needs_save = oidc_refresh_access_token_before_expiry(r, cfg, session,
			oidc_cfg_dir_refresh_access_token_before_expiry(r),
			oidc_cfg_dir_logout_on_error_refresh(r));
	if (needs_save == ERROR)
		return oidc_handle_logout_request(r, cfg, session, cfg->default_slo_url);

	/* if needed, refresh claims from the user info endpoint */
	if (oidc_refresh_claims_from_userinfo_endpoint(r, cfg, session) == TRUE)
		needs_save = TRUE;

	/*
	 * we're going to pass the information that we have to the application,
	 * but first we need to scrub the headers that we're going to use for security reasons
	 */
	oidc_scrub_headers(r);

	/* set the user authentication HTTP header if set and required */
	if ((r->user != NULL) && (authn_header != NULL))
		oidc_util_hdr_in_set(r, authn_header, r->user);

	const char *s_claims = NULL;
	const char *s_id_token = NULL;

	/* copy id_token and claims from session to request state and obtain their values */
	oidc_copy_tokens_to_request_state(r, session, &s_id_token, &s_claims);

	if ((cfg->pass_userinfo_as & OIDC_PASS_USERINFO_AS_CLAIMS)) {
		/* set the userinfo claims in the app headers */
		if (oidc_set_app_claims(r, cfg, session, s_claims) == FALSE)
			return HTTP_INTERNAL_SERVER_ERROR;
	}

	if ((cfg->pass_userinfo_as & OIDC_PASS_USERINFO_AS_JSON_OBJECT)) {
		/* pass the userinfo JSON object to the app in a header or environment variable */
		oidc_util_set_app_info(r, OIDC_APP_INFO_USERINFO_JSON, s_claims,
				OIDC_DEFAULT_HEADER_PREFIX, pass_headers, pass_envvars);
	}

	if ((cfg->pass_userinfo_as & OIDC_PASS_USERINFO_AS_JWT)) {
		if (cfg->session_type != OIDC_SESSION_TYPE_CLIENT_COOKIE) {
			/* get the compact serialized JWT from the session */
			const char *s_userinfo_jwt = oidc_session_get_userinfo_jwt(r,
					session);
			if (s_userinfo_jwt != NULL) {
				/* pass the compact serialized JWT to the app in a header or environment variable */
				oidc_util_set_app_info(r, OIDC_APP_INFO_USERINFO_JWT,
						s_userinfo_jwt,
						OIDC_DEFAULT_HEADER_PREFIX, pass_headers, pass_envvars);
			} else {
				oidc_debug(r,
						"configured to pass userinfo in a JWT, but no such JWT was found in the session (probably no such JWT was returned from the userinfo endpoint)");
			}
		} else {
			oidc_error(r,
					"session type \"client-cookie\" does not allow storing/passing a userinfo JWT; use \"" OIDCSessionType " server-cache\" for that");
		}
	}

	if ((cfg->pass_idtoken_as & OIDC_PASS_IDTOKEN_AS_CLAIMS)) {
		/* set the id_token in the app headers */
		if (oidc_set_app_claims(r, cfg, session, s_id_token) == FALSE)
			return HTTP_INTERNAL_SERVER_ERROR;
	}

	if ((cfg->pass_idtoken_as & OIDC_PASS_IDTOKEN_AS_PAYLOAD)) {
		/* pass the id_token JSON object to the app in a header or environment variable */
		oidc_util_set_app_info(r, OIDC_APP_INFO_ID_TOKEN_PAYLOAD, s_id_token,
				OIDC_DEFAULT_HEADER_PREFIX, pass_headers, pass_envvars);
	}

	if ((cfg->pass_idtoken_as & OIDC_PASS_IDTOKEN_AS_SERIALIZED)) {
		if (cfg->session_type != OIDC_SESSION_TYPE_CLIENT_COOKIE) {
			/* get the compact serialized JWT from the session */
			const char *s_id_token = oidc_session_get_idtoken(r, session);
			/* pass the compact serialized JWT to the app in a header or environment variable */
			oidc_util_set_app_info(r, OIDC_APP_INFO_ID_TOKEN, s_id_token,
					OIDC_DEFAULT_HEADER_PREFIX, pass_headers, pass_envvars);
		} else {
			oidc_error(r,
					"session type \"client-cookie\" does not allow storing/passing the id_token; use \"" OIDCSessionType " server-cache\" for that");
		}
	}

	/* pass the at, rt and at expiry to the application, possibly update the session expiry and save the session */
	if (oidc_session_pass_tokens_and_save(r, cfg, session, needs_save) == FALSE)
		return HTTP_INTERNAL_SERVER_ERROR;

	/* return "user authenticated" status */
	return OK;
}


static int oidc_check_userid_openidc(request_rec *r, oidc_cfg *c) {

	if (oidc_get_redirect_uri(r, c) == NULL) {
		oidc_error(r,
				"configuration error: the authentication type is set to \"" OIDC_AUTH_TYPE_OPENID_CONNECT "\" but " OIDCRedirectURI " has not been set");
		return HTTP_INTERNAL_SERVER_ERROR;
	}

	/* check if this is a sub-request or an initial request */
	if (ap_is_initial_req(r)) {

		int rc = OK;

		/* load the session from the request state; this will be a new "empty" session if no state exists */
		oidc_session_t *session = NULL;
		oidc_session_load(r, &session);

		/* see if the initial request is to the redirect URI; this handles potential logout too */
		if (oidc_util_request_matches_url(r, oidc_get_redirect_uri(r, c))) {

			/* handle request to the redirect_uri */
			rc = oidc_handle_redirect_uri_request(r, c, session);

			/* free resources allocated for the session */
			oidc_session_free(r, session);

			return rc;

			/* initial request to non-redirect URI, check if we have an existing session */
		} else if (session->remote_user != NULL) {

			/* this is initial request and we already have a session */
			rc = oidc_handle_existing_session(r, c, session);

			/* free resources allocated for the session */
			oidc_session_free(r, session);

			/* strip any cookies that we need to */
			oidc_strip_cookies(r);

			return rc;
		}

		/* free resources allocated for the session */
		oidc_session_free(r, session);

		/*
		 * else: initial request, we have no session and it is not an authorization or
		 *       discovery response: just hit the default flow for unauthenticated users
		 */
	} else {

		/* not an initial request, try to recycle what we've already established in the main request */
		if (r->main != NULL)
			r->user = r->main->user;
		else if (r->prev != NULL)
			r->user = r->prev->user;

		if (r->user != NULL) {

			/* this is a sub-request and we have a session (headers will have been scrubbed and set already) */
			oidc_debug(r,
					"recycling user '%s' from initial request for sub-request",
					r->user);

			/*
			 * apparently request state can get lost in sub-requests, so let's see
			 * if we need to restore id_token and/or claims from the session cache
			 */
			const char *s_id_token = oidc_request_state_get(r,
					OIDC_REQUEST_STATE_KEY_IDTOKEN);
			if (s_id_token == NULL) {

				oidc_session_t *session = NULL;
				oidc_session_load(r, &session);

				oidc_copy_tokens_to_request_state(r, session, NULL, NULL);

				/* free resources allocated for the session */
				oidc_session_free(r, session);
			}

			/* strip any cookies that we need to */
			oidc_strip_cookies(r);

			return OK;
		}
		/*
		 * else: not initial request, but we could not find a session, so:
		 * just hit the default flow for unauthenticated users
		 */
	}

	return oidc_handle_unauthenticated_user(r, c);
}


static int oidc_handle_unauthenticated_user(request_rec *r, oidc_cfg *c) {

	/* see if we've configured OIDCUnAuthAction for this path */
	switch (oidc_dir_cfg_unauth_action(r)) {
	case OIDC_UNAUTH_RETURN410:
		return HTTP_GONE;
	case OIDC_UNAUTH_RETURN401:
		return HTTP_UNAUTHORIZED;
	case OIDC_UNAUTH_PASS:
		r->user = "";

		/*
		 * we're not going to pass information about an authenticated user to the application,
		 * but we do need to scrub the headers that mod_auth_openidc would set for security reasons
		 */
		oidc_scrub_headers(r);

		return OK;

	case OIDC_UNAUTH_AUTHENTICATE:

		/*
		 * exception handling: if this looks like a XMLHttpRequest call we
		 * won't redirect the user and thus avoid creating a state cookie
		 * for a non-browser (= Javascript) call that will never return from the OP
		 */
		if (oidc_is_xml_http_request(r) == TRUE)
			return HTTP_UNAUTHORIZED;
	}

	/*
	 * else: no session (regardless of whether it is main or sub-request),
	 * and we need to authenticate the user
	 */
	return oidc_authenticate_user(r, c, NULL, oidc_get_current_url(r), NULL,
			NULL, NULL, oidc_dir_cfg_path_auth_request_params(r),
			oidc_dir_cfg_path_scope(r));
}


static const char *oidc_retrieve_claims_from_userinfo_endpoint(request_rec *r,
		oidc_cfg *c, oidc_provider_t *provider, const char *access_token,
		oidc_session_t *session, char *id_token_sub, char **userinfo_jwt) {

	oidc_debug(r, "enter");

	char *result = NULL;
	char *refreshed_access_token = NULL;

	/* see if a userinfo endpoint is set, otherwise there's nothing to do for us */
	if (provider->userinfo_endpoint_url == NULL) {
		oidc_debug(r,
				"not retrieving userinfo claims because userinfo_endpoint is not set");
		return NULL;
	}

	/* see if there's an access token, otherwise we can't call the userinfo endpoint at all */
	if (access_token == NULL) {
		oidc_debug(r,
				"not retrieving userinfo claims because access_token is not provided");
		return NULL;
	}

	if ((id_token_sub == NULL) && (session != NULL)) {

		// when refreshing claims from the userinfo endpoint
		json_t *id_token_claims = oidc_session_get_idtoken_claims_json(r,
				session);
		if (id_token_claims == NULL) {
			oidc_error(r, "no id_token_claims found in session");
			return NULL;
		}

		oidc_jose_get_string(r->pool, id_token_claims, OIDC_CLAIM_SUB, FALSE,
				&id_token_sub, NULL);
	}

	// TODO: return code should indicate whether the token expired or some other error occurred
	// TODO: long-term: session storage should be JSON (with explicit types and less conversion, using standard routines)

	/* try to get claims from the userinfo endpoint using the provided access token */
	if (oidc_proto_resolve_userinfo(r, c, provider, id_token_sub, access_token,
			&result, userinfo_jwt) == FALSE) {

		/* see if we have an existing session and we are refreshing the user info claims */
		if (session != NULL) {

			/* first call to user info endpoint failed, but the access token may have just expired, so refresh it */
			if (oidc_refresh_access_token(r, c, session, provider,
					&refreshed_access_token) == TRUE) {

				/* try again with the new access token */
				if (oidc_proto_resolve_userinfo(r, c, provider, id_token_sub,
						refreshed_access_token, &result, userinfo_jwt) == FALSE) {

					oidc_error(r,
							"resolving user info claims with the refreshed access token failed, nothing will be stored in the session");
					result = NULL;

				}

			} else {

				oidc_warn(r,
						"refreshing access token failed, claims will not be retrieved/refreshed from the userinfo endpoint");
				result = NULL;

			}

		} else {

			oidc_error(r,
					"resolving user info claims with the existing/provided access token failed, nothing will be stored in the session");
			result = NULL;

		}
	}

	return result;
}