FLAC__bool FLAC__bitreader_read_rice_signed_block(FLAC__BitReader *br, int vals[], uint32_t nvals, uint32_t parameter)
{
	/* try and get br->consumed_words and br->consumed_bits into register;
	 * must remember to flush them back to *br before calling other
	 * bitreader functions that use them, and before returning */
	uint32_t cwords, words, lsbs, msbs, x, y;
	uint32_t ucbits; /* keep track of the number of unconsumed bits in word */
	brword b;
	int *val, *end;

	FLAC__ASSERT(0 != br);
	FLAC__ASSERT(0 != br->buffer);
	/* WATCHOUT: code does not work with <32bit words; we can make things much faster with this assertion */
	FLAC__ASSERT(FLAC__BITS_PER_WORD >= 32);
	FLAC__ASSERT(parameter < 32);
	/* the above two asserts also guarantee that the binary part never straddles more than 2 words, so we don't have to loop to read it */

	val = vals;
	end = vals + nvals;

	if(parameter == 0) {
		while(val < end) {
			/* read the unary MSBs and end bit */
			if(!FLAC__bitreader_read_unary_unsigned(br, &msbs))
				return false;

			*val++ = (int)(msbs >> 1) ^ -(int)(msbs & 1);
		}

		return true;
	}

	FLAC__ASSERT(parameter > 0);

	cwords = br->consumed_words;
	words = br->words;

	/* if we've not consumed up to a partial tail word... */
	if(cwords >= words) {
		x = 0;
		goto process_tail;
	}

	ucbits = FLAC__BITS_PER_WORD - br->consumed_bits;
	b = br->buffer[cwords] << br->consumed_bits;  /* keep unconsumed bits aligned to left */

	while(val < end) {
		/* read the unary MSBs and end bit */
		x = y = COUNT_ZERO_MSBS2(b);
		if(x == FLAC__BITS_PER_WORD) {
			x = ucbits;
			do {
				/* didn't find stop bit yet, have to keep going... */
				cwords++;
				if (cwords >= words)
					goto incomplete_msbs;
				b = br->buffer[cwords];
				y = COUNT_ZERO_MSBS2(b);
				x += y;
			} while(y == FLAC__BITS_PER_WORD);
		}
		b <<= y;
		b <<= 1; /* account for stop bit */
		ucbits = (ucbits - x - 1) % FLAC__BITS_PER_WORD;
		msbs = x;

		/* read the binary LSBs */
		x = (FLAC__uint32)(b >> (FLAC__BITS_PER_WORD - parameter)); /* parameter < 32, so we can cast to 32-bit uint32_t */
		if(parameter <= ucbits) {
			ucbits -= parameter;
			b <<= parameter;
		} else {
			/* there are still bits left to read, they will all be in the next word */
			cwords++;
			if (cwords >= words)
				goto incomplete_lsbs;
			b = br->buffer[cwords];
			ucbits += FLAC__BITS_PER_WORD - parameter;
			x |= (FLAC__uint32)(b >> ucbits);
			b <<= FLAC__BITS_PER_WORD - ucbits;
		}
		lsbs = x;

		/* compose the value */
		x = (msbs << parameter) | lsbs;
		*val++ = (int)(x >> 1) ^ -(int)(x & 1);

		continue;

		/* at this point we've eaten up all the whole words */
process_tail:
		do {
			if(0) {
incomplete_msbs:
				br->consumed_bits = 0;
				br->consumed_words = cwords;
			}

			/* read the unary MSBs and end bit */
			if(!FLAC__bitreader_read_unary_unsigned(br, &msbs))
				return false;
			msbs += x;
			x = ucbits = 0;

			if(0) {
incomplete_lsbs:
				br->consumed_bits = 0;
				br->consumed_words = cwords;
			}

			/* read the binary LSBs */
			if(!FLAC__bitreader_read_raw_uint32(br, &lsbs, parameter - ucbits))
				return false;
			lsbs = x | lsbs;

			/* compose the value */
			x = (msbs << parameter) | lsbs;
			*val++ = (int)(x >> 1) ^ -(int)(x & 1);
			x = 0;

			cwords = br->consumed_words;
			words = br->words;
			ucbits = FLAC__BITS_PER_WORD - br->consumed_bits;
			b = cwords < br->capacity ? br->buffer[cwords] << br->consumed_bits : 0;
		} while(cwords >= words && val < end);
	}

	if(ucbits == 0 && cwords < words) {
		/* don't leave the head word with no unconsumed bits */
		cwords++;
		ucbits = FLAC__BITS_PER_WORD;
	}

	br->consumed_bits = FLAC__BITS_PER_WORD - ucbits;
	br->consumed_words = cwords;

	return true;
}


PasswordProcess (
  IN  UI_MENU_OPTION              *MenuOption
  )
{
  CHAR16                          *StringPtr;
  CHAR16                          *TempString;
  UINTN                           Maximum;
  EFI_STATUS                      Status;
  EFI_IFR_PASSWORD                *PasswordInfo;
  FORM_DISPLAY_ENGINE_STATEMENT   *Question;
  EFI_INPUT_KEY                   Key;

  Question     = MenuOption->ThisTag;
  PasswordInfo = (EFI_IFR_PASSWORD *) Question->OpCode;
  Maximum      = PasswordInfo->MaxSize;
  Status       = EFI_SUCCESS;

  StringPtr = AllocateZeroPool ((Maximum + 1) * sizeof (CHAR16));
  ASSERT (StringPtr);

  //
  // Use a NULL password to test whether old password is required
  //
  *StringPtr = 0;
  Status = Question->PasswordCheck (gFormData, Question, StringPtr);
  if (Status == EFI_NOT_AVAILABLE_YET || Status == EFI_UNSUPPORTED) {
    //
    // Password can't be set now.
    //
    if (Status == EFI_UNSUPPORTED) {
      do {
        CreateDialog (&Key, gEmptyString, gPasswordUnsupported, gPressEnter, gEmptyString, NULL);
      } while (Key.UnicodeChar != CHAR_CARRIAGE_RETURN);
    }
    FreePool (StringPtr);
    return EFI_SUCCESS;
  }

  if (EFI_ERROR (Status)) {
    //
    // Old password exist, ask user for the old password
    //
    Status = ReadString (MenuOption, gPromptForPassword, StringPtr);
    if (EFI_ERROR (Status)) {
      FreePool (StringPtr);
      return Status;
    }

    //
    // Check user input old password
    //
    Status = Question->PasswordCheck (gFormData, Question, StringPtr);
    if (EFI_ERROR (Status)) {
      if (Status == EFI_NOT_READY) {
        //
        // Typed in old password incorrect
        //
        PasswordInvalid ();
      } else {
        Status = EFI_SUCCESS;
      }

      FreePool (StringPtr);
      return Status;
    }
  }

  //
  // Ask for new password
  //
  ZeroMem (StringPtr, (Maximum + 1) * sizeof (CHAR16));
  Status = ReadString (MenuOption, gPromptForNewPassword, StringPtr);
  if (EFI_ERROR (Status)) {
    //
    // Reset state machine for password
    //
    Question->PasswordCheck (gFormData, Question, NULL);
    FreePool (StringPtr);
    return Status;
  }

  //
  // Confirm new password
  //
  TempString = AllocateZeroPool ((Maximum + 1) * sizeof (CHAR16));
  ASSERT (TempString);
  Status = ReadString (MenuOption, gConfirmPassword, TempString);
  if (EFI_ERROR (Status)) {
    //
    // Reset state machine for password
    //
    Question->PasswordCheck (gFormData, Question, NULL);
    FreePool (StringPtr);
    FreePool (TempString);
    return Status;
  }

  //
  // Compare two typed-in new passwords
  //
  if (StrCmp (StringPtr, TempString) == 0) {
    gUserInput->InputValue.Buffer = AllocateCopyPool (Question->CurrentValue.BufferLen, StringPtr);
    gUserInput->InputValue.BufferLen = Question->CurrentValue.BufferLen;
    gUserInput->InputValue.Type = Question->CurrentValue.Type;
    gUserInput->InputValue.Value.string = HiiSetString(gFormData->HiiHandle, gUserInput->InputValue.Value.string, StringPtr, NULL);

    Status = EFI_SUCCESS;
  } else {
    //
    // Reset state machine for password
    //
    Question->PasswordCheck (gFormData, Question, NULL);

    //
    // Two password mismatch, prompt error message
    //
    do {
      CreateDialog (&Key, gEmptyString, gConfirmError, gPressEnter, gEmptyString, NULL);
    } while (Key.UnicodeChar != CHAR_CARRIAGE_RETURN);

    Status = EFI_INVALID_PARAMETER;
  }
  ZeroMem (TempString, (Maximum + 1) * sizeof (CHAR16));
  ZeroMem (StringPtr, (Maximum + 1) * sizeof (CHAR16));
  FreePool (TempString);
  FreePool (StringPtr);

  return Status;
}

MdeModulePkg/DisplayEngine: Zero memory before free (CVE-2019-14558)

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=1611

Cc: Liming Gao <liming.gao@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Cc: Jian J Wang <jian.j.wang@intel.com>
Signed-off-by: Dandan Bi <dandan.bi@intel.com>
Reviewed-by: Eric Dong <eric.dong@intel.com>
Reviewed-by: Jian J Wang <jian.j.wang@intel.com>


PasswordProcess (
  IN  UI_MENU_OPTION              *MenuOption
  )
{
  CHAR16                          *StringPtr;
  CHAR16                          *TempString;
  UINTN                           Maximum;
  EFI_STATUS                      Status;
  EFI_IFR_PASSWORD                *PasswordInfo;
  FORM_DISPLAY_ENGINE_STATEMENT   *Question;
  EFI_INPUT_KEY                   Key;

  Question     = MenuOption->ThisTag;
  PasswordInfo = (EFI_IFR_PASSWORD *) Question->OpCode;
  Maximum      = PasswordInfo->MaxSize;
  Status       = EFI_SUCCESS;

  StringPtr = AllocateZeroPool ((Maximum + 1) * sizeof (CHAR16));
  ASSERT (StringPtr);

  //
  // Use a NULL password to test whether old password is required
  //
  *StringPtr = 0;
  Status = Question->PasswordCheck (gFormData, Question, StringPtr);
  if (Status == EFI_NOT_AVAILABLE_YET || Status == EFI_UNSUPPORTED) {
    //
    // Password can't be set now.
    //
    if (Status == EFI_UNSUPPORTED) {
      do {
        CreateDialog (&Key, gEmptyString, gPasswordUnsupported, gPressEnter, gEmptyString, NULL);
      } while (Key.UnicodeChar != CHAR_CARRIAGE_RETURN);
    }
    FreePool (StringPtr);
    return EFI_SUCCESS;
  }

  if (EFI_ERROR (Status)) {
    //
    // Old password exist, ask user for the old password
    //
    Status = ReadString (MenuOption, gPromptForPassword, StringPtr);
    if (EFI_ERROR (Status)) {
      ZeroMem (StringPtr, (Maximum + 1) * sizeof (CHAR16));
      FreePool (StringPtr);
      return Status;
    }

    //
    // Check user input old password
    //
    Status = Question->PasswordCheck (gFormData, Question, StringPtr);
    if (EFI_ERROR (Status)) {
      if (Status == EFI_NOT_READY) {
        //
        // Typed in old password incorrect
        //
        PasswordInvalid ();
      } else {
        Status = EFI_SUCCESS;
      }
      ZeroMem (StringPtr, (Maximum + 1) * sizeof (CHAR16));
      FreePool (StringPtr);
      return Status;
    }
  }

  //
  // Ask for new password
  //
  ZeroMem (StringPtr, (Maximum + 1) * sizeof (CHAR16));
  Status = ReadString (MenuOption, gPromptForNewPassword, StringPtr);
  if (EFI_ERROR (Status)) {
    //
    // Reset state machine for password
    //
    Question->PasswordCheck (gFormData, Question, NULL);
    ZeroMem (StringPtr, (Maximum + 1) * sizeof (CHAR16));
    FreePool (StringPtr);
    return Status;
  }

  //
  // Confirm new password
  //
  TempString = AllocateZeroPool ((Maximum + 1) * sizeof (CHAR16));
  ASSERT (TempString);
  Status = ReadString (MenuOption, gConfirmPassword, TempString);
  if (EFI_ERROR (Status)) {
    //
    // Reset state machine for password
    //
    Question->PasswordCheck (gFormData, Question, NULL);
    ZeroMem (StringPtr, (Maximum + 1) * sizeof (CHAR16));
    ZeroMem (TempString, (Maximum + 1) * sizeof (CHAR16));
    FreePool (StringPtr);
    FreePool (TempString);
    return Status;
  }

  //
  // Compare two typed-in new passwords
  //
  if (StrCmp (StringPtr, TempString) == 0) {
    gUserInput->InputValue.Buffer = AllocateCopyPool (Question->CurrentValue.BufferLen, StringPtr);
    gUserInput->InputValue.BufferLen = Question->CurrentValue.BufferLen;
    gUserInput->InputValue.Type = Question->CurrentValue.Type;
    gUserInput->InputValue.Value.string = HiiSetString(gFormData->HiiHandle, gUserInput->InputValue.Value.string, StringPtr, NULL);

    Status = EFI_SUCCESS;
  } else {
    //
    // Reset state machine for password
    //
    Question->PasswordCheck (gFormData, Question, NULL);

    //
    // Two password mismatch, prompt error message
    //
    do {
      CreateDialog (&Key, gEmptyString, gConfirmError, gPressEnter, gEmptyString, NULL);
    } while (Key.UnicodeChar != CHAR_CARRIAGE_RETURN);

    Status = EFI_INVALID_PARAMETER;
  }
  ZeroMem (TempString, (Maximum + 1) * sizeof (CHAR16));
  ZeroMem (StringPtr, (Maximum + 1) * sizeof (CHAR16));
  FreePool (TempString);
  FreePool (StringPtr);

  return Status;
}


void stralgoLCS(client *c) {
    uint32_t i, j;
    long long minmatchlen = 0;
    sds a = NULL, b = NULL;
    int getlen = 0, getidx = 0, withmatchlen = 0;
    robj *obja = NULL, *objb = NULL;

    for (j = 2; j < (uint32_t)c->argc; j++) {
        char *opt = c->argv[j]->ptr;
        int moreargs = (c->argc-1) - j;

        if (!strcasecmp(opt,"IDX")) {
            getidx = 1;
        } else if (!strcasecmp(opt,"LEN")) {
            getlen = 1;
        } else if (!strcasecmp(opt,"WITHMATCHLEN")) {
            withmatchlen = 1;
        } else if (!strcasecmp(opt,"MINMATCHLEN") && moreargs) {
            if (getLongLongFromObjectOrReply(c,c->argv[j+1],&minmatchlen,NULL)
                != C_OK) goto cleanup;
            if (minmatchlen < 0) minmatchlen = 0;
            j++;
        } else if (!strcasecmp(opt,"STRINGS") && moreargs > 1) {
            if (a != NULL) {
                addReplyError(c,"Either use STRINGS or KEYS");
                goto cleanup;
            }
            a = c->argv[j+1]->ptr;
            b = c->argv[j+2]->ptr;
            j += 2;
        } else if (!strcasecmp(opt,"KEYS") && moreargs > 1) {
            if (a != NULL) {
                addReplyError(c,"Either use STRINGS or KEYS");
                goto cleanup;
            }
            obja = lookupKeyRead(c->db,c->argv[j+1]);
            objb = lookupKeyRead(c->db,c->argv[j+2]);
            if ((obja && obja->type != OBJ_STRING) ||
                (objb && objb->type != OBJ_STRING))
            {
                addReplyError(c,
                    "The specified keys must contain string values");
                /* Don't cleanup the objects, we need to do that
                 * only after calling getDecodedObject(). */
                obja = NULL;
                objb = NULL;
                goto cleanup;
            }
            obja = obja ? getDecodedObject(obja) : createStringObject("",0);
            objb = objb ? getDecodedObject(objb) : createStringObject("",0);
            a = obja->ptr;
            b = objb->ptr;
            j += 2;
        } else {
            addReplyErrorObject(c,shared.syntaxerr);
            goto cleanup;
        }
    }

    /* Complain if the user passed ambiguous parameters. */
    if (a == NULL) {
        addReplyError(c,"Please specify two strings: "
                        "STRINGS or KEYS options are mandatory");
        goto cleanup;
    } else if (getlen && getidx) {
        addReplyError(c,
            "If you want both the length and indexes, please "
            "just use IDX.");
        goto cleanup;
    }

    /* Compute the LCS using the vanilla dynamic programming technique of
     * building a table of LCS(x,y) substrings. */
    uint32_t alen = sdslen(a);
    uint32_t blen = sdslen(b);

    /* Setup an uint32_t array to store at LCS[i,j] the length of the
     * LCS A0..i-1, B0..j-1. Note that we have a linear array here, so
     * we index it as LCS[j+(blen+1)*j] */
    uint32_t *lcs = zmalloc((alen+1)*(blen+1)*sizeof(uint32_t));
    #define LCS(A,B) lcs[(B)+((A)*(blen+1))]

    /* Start building the LCS table. */
    for (uint32_t i = 0; i <= alen; i++) {
        for (uint32_t j = 0; j <= blen; j++) {
            if (i == 0 || j == 0) {
                /* If one substring has length of zero, the
                 * LCS length is zero. */
                LCS(i,j) = 0;
            } else if (a[i-1] == b[j-1]) {
                /* The len LCS (and the LCS itself) of two
                 * sequences with the same final character, is the
                 * LCS of the two sequences without the last char
                 * plus that last char. */
                LCS(i,j) = LCS(i-1,j-1)+1;
            } else {
                /* If the last character is different, take the longest
                 * between the LCS of the first string and the second
                 * minus the last char, and the reverse. */
                uint32_t lcs1 = LCS(i-1,j);
                uint32_t lcs2 = LCS(i,j-1);
                LCS(i,j) = lcs1 > lcs2 ? lcs1 : lcs2;
            }
        }
    }

    /* Store the actual LCS string in "result" if needed. We create
     * it backward, but the length is already known, we store it into idx. */
    uint32_t idx = LCS(alen,blen);
    sds result = NULL;        /* Resulting LCS string. */
    void *arraylenptr = NULL; /* Deffered length of the array for IDX. */
    uint32_t arange_start = alen, /* alen signals that values are not set. */
             arange_end = 0,
             brange_start = 0,
             brange_end = 0;

    /* Do we need to compute the actual LCS string? Allocate it in that case. */
    int computelcs = getidx || !getlen;
    if (computelcs) result = sdsnewlen(SDS_NOINIT,idx);

    /* Start with a deferred array if we have to emit the ranges. */
    uint32_t arraylen = 0;  /* Number of ranges emitted in the array. */
    if (getidx) {
        addReplyMapLen(c,2);
        addReplyBulkCString(c,"matches");
        arraylenptr = addReplyDeferredLen(c);
    }

    i = alen, j = blen;
    while (computelcs && i > 0 && j > 0) {
        int emit_range = 0;
        if (a[i-1] == b[j-1]) {
            /* If there is a match, store the character and reduce
             * the indexes to look for a new match. */
            result[idx-1] = a[i-1];

            /* Track the current range. */
            if (arange_start == alen) {
                arange_start = i-1;
                arange_end = i-1;
                brange_start = j-1;
                brange_end = j-1;
            } else {
                /* Let's see if we can extend the range backward since
                 * it is contiguous. */
                if (arange_start == i && brange_start == j) {
                    arange_start--;
                    brange_start--;
                } else {
                    emit_range = 1;
                }
            }
            /* Emit the range if we matched with the first byte of
             * one of the two strings. We'll exit the loop ASAP. */
            if (arange_start == 0 || brange_start == 0) emit_range = 1;
            idx--; i--; j--;
        } else {
            /* Otherwise reduce i and j depending on the largest
             * LCS between, to understand what direction we need to go. */
            uint32_t lcs1 = LCS(i-1,j);
            uint32_t lcs2 = LCS(i,j-1);
            if (lcs1 > lcs2)
                i--;
            else
                j--;
            if (arange_start != alen) emit_range = 1;
        }

        /* Emit the current range if needed. */
        uint32_t match_len = arange_end - arange_start + 1;
        if (emit_range) {
            if (minmatchlen == 0 || match_len >= minmatchlen) {
                if (arraylenptr) {
                    addReplyArrayLen(c,2+withmatchlen);
                    addReplyArrayLen(c,2);
                    addReplyLongLong(c,arange_start);
                    addReplyLongLong(c,arange_end);
                    addReplyArrayLen(c,2);
                    addReplyLongLong(c,brange_start);
                    addReplyLongLong(c,brange_end);
                    if (withmatchlen) addReplyLongLong(c,match_len);
                    arraylen++;
                }
            }
            arange_start = alen; /* Restart at the next match. */
        }
    }

    /* Signal modified key, increment dirty, ... */

    /* Reply depending on the given options. */
    if (arraylenptr) {
        addReplyBulkCString(c,"len");
        addReplyLongLong(c,LCS(alen,blen));
        setDeferredArrayLen(c,arraylenptr,arraylen);
    } else if (getlen) {
        addReplyLongLong(c,LCS(alen,blen));
    } else {
        addReplyBulkSds(c,result);
        result = NULL;
    }

    /* Cleanup. */
    sdsfree(result);
    zfree(lcs);

cleanup:
    if (obja) decrRefCount(obja);
    if (objb) decrRefCount(objb);
    return;
}

Fix integer overflow in STRALGO LCS (CVE-2021-29477)

An integer overflow bug in Redis version 6.0 or newer could be exploited using
the STRALGO LCS command to corrupt the heap and potentially result with remote
code execution.

(cherry picked from commit f0c5f920d0f88bd8aa376a2c05af4902789d1ef9)


void stralgoLCS(client *c) {
    uint32_t i, j;
    long long minmatchlen = 0;
    sds a = NULL, b = NULL;
    int getlen = 0, getidx = 0, withmatchlen = 0;
    robj *obja = NULL, *objb = NULL;

    for (j = 2; j < (uint32_t)c->argc; j++) {
        char *opt = c->argv[j]->ptr;
        int moreargs = (c->argc-1) - j;

        if (!strcasecmp(opt,"IDX")) {
            getidx = 1;
        } else if (!strcasecmp(opt,"LEN")) {
            getlen = 1;
        } else if (!strcasecmp(opt,"WITHMATCHLEN")) {
            withmatchlen = 1;
        } else if (!strcasecmp(opt,"MINMATCHLEN") && moreargs) {
            if (getLongLongFromObjectOrReply(c,c->argv[j+1],&minmatchlen,NULL)
                != C_OK) goto cleanup;
            if (minmatchlen < 0) minmatchlen = 0;
            j++;
        } else if (!strcasecmp(opt,"STRINGS") && moreargs > 1) {
            if (a != NULL) {
                addReplyError(c,"Either use STRINGS or KEYS");
                goto cleanup;
            }
            a = c->argv[j+1]->ptr;
            b = c->argv[j+2]->ptr;
            j += 2;
        } else if (!strcasecmp(opt,"KEYS") && moreargs > 1) {
            if (a != NULL) {
                addReplyError(c,"Either use STRINGS or KEYS");
                goto cleanup;
            }
            obja = lookupKeyRead(c->db,c->argv[j+1]);
            objb = lookupKeyRead(c->db,c->argv[j+2]);
            if ((obja && obja->type != OBJ_STRING) ||
                (objb && objb->type != OBJ_STRING))
            {
                addReplyError(c,
                    "The specified keys must contain string values");
                /* Don't cleanup the objects, we need to do that
                 * only after calling getDecodedObject(). */
                obja = NULL;
                objb = NULL;
                goto cleanup;
            }
            obja = obja ? getDecodedObject(obja) : createStringObject("",0);
            objb = objb ? getDecodedObject(objb) : createStringObject("",0);
            a = obja->ptr;
            b = objb->ptr;
            j += 2;
        } else {
            addReplyErrorObject(c,shared.syntaxerr);
            goto cleanup;
        }
    }

    /* Complain if the user passed ambiguous parameters. */
    if (a == NULL) {
        addReplyError(c,"Please specify two strings: "
                        "STRINGS or KEYS options are mandatory");
        goto cleanup;
    } else if (getlen && getidx) {
        addReplyError(c,
            "If you want both the length and indexes, please "
            "just use IDX.");
        goto cleanup;
    }

    /* Compute the LCS using the vanilla dynamic programming technique of
     * building a table of LCS(x,y) substrings. */
    uint32_t alen = sdslen(a);
    uint32_t blen = sdslen(b);

    /* Setup an uint32_t array to store at LCS[i,j] the length of the
     * LCS A0..i-1, B0..j-1. Note that we have a linear array here, so
     * we index it as LCS[j+(blen+1)*j] */
    uint32_t *lcs = zmalloc((size_t)(alen+1)*(blen+1)*sizeof(uint32_t));
    #define LCS(A,B) lcs[(B)+((A)*(blen+1))]

    /* Start building the LCS table. */
    for (uint32_t i = 0; i <= alen; i++) {
        for (uint32_t j = 0; j <= blen; j++) {
            if (i == 0 || j == 0) {
                /* If one substring has length of zero, the
                 * LCS length is zero. */
                LCS(i,j) = 0;
            } else if (a[i-1] == b[j-1]) {
                /* The len LCS (and the LCS itself) of two
                 * sequences with the same final character, is the
                 * LCS of the two sequences without the last char
                 * plus that last char. */
                LCS(i,j) = LCS(i-1,j-1)+1;
            } else {
                /* If the last character is different, take the longest
                 * between the LCS of the first string and the second
                 * minus the last char, and the reverse. */
                uint32_t lcs1 = LCS(i-1,j);
                uint32_t lcs2 = LCS(i,j-1);
                LCS(i,j) = lcs1 > lcs2 ? lcs1 : lcs2;
            }
        }
    }

    /* Store the actual LCS string in "result" if needed. We create
     * it backward, but the length is already known, we store it into idx. */
    uint32_t idx = LCS(alen,blen);
    sds result = NULL;        /* Resulting LCS string. */
    void *arraylenptr = NULL; /* Deffered length of the array for IDX. */
    uint32_t arange_start = alen, /* alen signals that values are not set. */
             arange_end = 0,
             brange_start = 0,
             brange_end = 0;

    /* Do we need to compute the actual LCS string? Allocate it in that case. */
    int computelcs = getidx || !getlen;
    if (computelcs) result = sdsnewlen(SDS_NOINIT,idx);

    /* Start with a deferred array if we have to emit the ranges. */
    uint32_t arraylen = 0;  /* Number of ranges emitted in the array. */
    if (getidx) {
        addReplyMapLen(c,2);
        addReplyBulkCString(c,"matches");
        arraylenptr = addReplyDeferredLen(c);
    }

    i = alen, j = blen;
    while (computelcs && i > 0 && j > 0) {
        int emit_range = 0;
        if (a[i-1] == b[j-1]) {
            /* If there is a match, store the character and reduce
             * the indexes to look for a new match. */
            result[idx-1] = a[i-1];

            /* Track the current range. */
            if (arange_start == alen) {
                arange_start = i-1;
                arange_end = i-1;
                brange_start = j-1;
                brange_end = j-1;
            } else {
                /* Let's see if we can extend the range backward since
                 * it is contiguous. */
                if (arange_start == i && brange_start == j) {
                    arange_start--;
                    brange_start--;
                } else {
                    emit_range = 1;
                }
            }
            /* Emit the range if we matched with the first byte of
             * one of the two strings. We'll exit the loop ASAP. */
            if (arange_start == 0 || brange_start == 0) emit_range = 1;
            idx--; i--; j--;
        } else {
            /* Otherwise reduce i and j depending on the largest
             * LCS between, to understand what direction we need to go. */
            uint32_t lcs1 = LCS(i-1,j);
            uint32_t lcs2 = LCS(i,j-1);
            if (lcs1 > lcs2)
                i--;
            else
                j--;
            if (arange_start != alen) emit_range = 1;
        }

        /* Emit the current range if needed. */
        uint32_t match_len = arange_end - arange_start + 1;
        if (emit_range) {
            if (minmatchlen == 0 || match_len >= minmatchlen) {
                if (arraylenptr) {
                    addReplyArrayLen(c,2+withmatchlen);
                    addReplyArrayLen(c,2);
                    addReplyLongLong(c,arange_start);
                    addReplyLongLong(c,arange_end);
                    addReplyArrayLen(c,2);
                    addReplyLongLong(c,brange_start);
                    addReplyLongLong(c,brange_end);
                    if (withmatchlen) addReplyLongLong(c,match_len);
                    arraylen++;
                }
            }
            arange_start = alen; /* Restart at the next match. */
        }
    }

    /* Signal modified key, increment dirty, ... */

    /* Reply depending on the given options. */
    if (arraylenptr) {
        addReplyBulkCString(c,"len");
        addReplyLongLong(c,LCS(alen,blen));
        setDeferredArrayLen(c,arraylenptr,arraylen);
    } else if (getlen) {
        addReplyLongLong(c,LCS(alen,blen));
    } else {
        addReplyBulkSds(c,result);
        result = NULL;
    }

    /* Cleanup. */
    sdsfree(result);
    zfree(lcs);

cleanup:
    if (obja) decrRefCount(obja);
    if (objb) decrRefCount(objb);
    return;
}


int RGWGetObj_ObjStore_S3::send_response_data(bufferlist& bl, off_t bl_ofs,
					      off_t bl_len)
{
  const char *content_type = NULL;
  string content_type_str;
  map<string, string> response_attrs;
  map<string, string>::iterator riter;
  bufferlist metadata_bl;

  if (sent_header)
    goto send_data;

  if (custom_http_ret) {
    set_req_state_err(s, 0);
    dump_errno(s, custom_http_ret);
  } else {
    set_req_state_err(s, (partial_content && !op_ret) ? STATUS_PARTIAL_CONTENT
                  : op_ret);
    dump_errno(s);
  }

  if (op_ret)
    goto done;

  if (range_str)
    dump_range(s, start, end, s->obj_size);

  if (s->system_request &&
      s->info.args.exists(RGW_SYS_PARAM_PREFIX "prepend-metadata")) {

    dump_header(s, "Rgwx-Object-Size", (long long)total_len);

    if (rgwx_stat) {
      /*
       * in this case, we're not returning the object's content, only the prepended
       * extra metadata
       */
      total_len = 0;
    }

    /* JSON encode object metadata */
    JSONFormatter jf;
    jf.open_object_section("obj_metadata");
    encode_json("attrs", attrs, &jf);
    utime_t ut(lastmod);
    encode_json("mtime", ut, &jf);
    jf.close_section();
    stringstream ss;
    jf.flush(ss);
    metadata_bl.append(ss.str());
    dump_header(s, "Rgwx-Embedded-Metadata-Len", metadata_bl.length());
    total_len += metadata_bl.length();
  }

  if (s->system_request && !real_clock::is_zero(lastmod)) {
    /* we end up dumping mtime in two different methods, a bit redundant */
    dump_epoch_header(s, "Rgwx-Mtime", lastmod);
    uint64_t pg_ver = 0;
    int r = decode_attr_bl_single_value(attrs, RGW_ATTR_PG_VER, &pg_ver, (uint64_t)0);
    if (r < 0) {
      ldout(s->cct, 0) << "ERROR: failed to decode pg ver attr, ignoring" << dendl;
    }
    dump_header(s, "Rgwx-Obj-PG-Ver", pg_ver);

    uint32_t source_zone_short_id = 0;
    r = decode_attr_bl_single_value(attrs, RGW_ATTR_SOURCE_ZONE, &source_zone_short_id, (uint32_t)0);
    if (r < 0) {
      ldout(s->cct, 0) << "ERROR: failed to decode pg ver attr, ignoring" << dendl;
    }
    if (source_zone_short_id != 0) {
      dump_header(s, "Rgwx-Source-Zone-Short-Id", source_zone_short_id);
    }
  }

  for (auto &it : crypt_http_responses)
    dump_header(s, it.first, it.second);

  dump_content_length(s, total_len);
  dump_last_modified(s, lastmod);
  dump_header_if_nonempty(s, "x-amz-version-id", version_id);
  if (attrs.find(RGW_ATTR_APPEND_PART_NUM) != attrs.end()) {
    dump_header(s, "x-rgw-object-type", "Appendable");
    dump_header(s, "x-rgw-next-append-position", s->obj_size);
  } else {
    dump_header(s, "x-rgw-object-type", "Normal");
  }

  if (! op_ret) {
    if (! lo_etag.empty()) {
      /* Handle etag of Swift API's large objects (DLO/SLO). It's entirerly
       * legit to perform GET on them through S3 API. In such situation,
       * a client should receive the composited content with corresponding
       * etag value. */
      dump_etag(s, lo_etag);
    } else {
      auto iter = attrs.find(RGW_ATTR_ETAG);
      if (iter != attrs.end()) {
        dump_etag(s, iter->second.to_str());
      }
    }

    for (struct response_attr_param *p = resp_attr_params; p->param; p++) {
      bool exists;
      string val = s->info.args.get(p->param, &exists);
      if (exists) {
	/* reject unauthenticated response header manipulation, see
	 * https://docs.aws.amazon.com/AmazonS3/latest/API/API_GetObject.html */
	if (s->auth.identity->is_anonymous()) {
	  return -ERR_INVALID_REQUEST;
	}
	if (strcmp(p->param, "response-content-type") != 0) {
	  response_attrs[p->http_attr] = val;
	} else {
	  content_type_str = val;
	  content_type = content_type_str.c_str();
	}
      }
    }

    for (auto iter = attrs.begin(); iter != attrs.end(); ++iter) {
      const char *name = iter->first.c_str();
      map<string, string>::iterator aiter = rgw_to_http_attrs.find(name);
      if (aiter != rgw_to_http_attrs.end()) {
        if (response_attrs.count(aiter->second) == 0) {
          /* Was not already overridden by a response param. */

          size_t len = iter->second.length();
          string s(iter->second.c_str(), len);
          while (len && !s[len - 1]) {
            --len;
            s.resize(len);
          }
          response_attrs[aiter->second] = s;
        }
      } else if (iter->first.compare(RGW_ATTR_CONTENT_TYPE) == 0) {
        /* Special handling for content_type. */
        if (!content_type) {
          content_type_str = rgw_bl_str(iter->second);
          content_type = content_type_str.c_str();
        }
      } else if (strcmp(name, RGW_ATTR_SLO_UINDICATOR) == 0) {
        // this attr has an extra length prefix from encode() in prior versions
        dump_header(s, "X-Object-Meta-Static-Large-Object", "True");
      } else if (strncmp(name, RGW_ATTR_META_PREFIX,
			 sizeof(RGW_ATTR_META_PREFIX)-1) == 0) {
        /* User custom metadata. */
        name += sizeof(RGW_ATTR_PREFIX) - 1;
        dump_header(s, name, iter->second);
      } else if (iter->first.compare(RGW_ATTR_TAGS) == 0) {
        RGWObjTags obj_tags;
        try{
          auto it = iter->second.cbegin();
          obj_tags.decode(it);
        } catch (buffer::error &err) {
          ldout(s->cct,0) << "Error caught buffer::error couldn't decode TagSet " << dendl;
        }
        dump_header(s, RGW_AMZ_TAG_COUNT, obj_tags.count());
      } else if (iter->first.compare(RGW_ATTR_OBJECT_RETENTION) == 0 && get_retention){
        RGWObjectRetention retention;
        try {
          decode(retention, iter->second);
          dump_header(s, "x-amz-object-lock-mode", retention.get_mode());
          dump_time_header(s, "x-amz-object-lock-retain-until-date", retention.get_retain_until_date());
        } catch (buffer::error& err) {
          ldpp_dout(this, 0) << "ERROR: failed to decode RGWObjectRetention" << dendl;
        }
      } else if (iter->first.compare(RGW_ATTR_OBJECT_LEGAL_HOLD) == 0 && get_legal_hold) {
        RGWObjectLegalHold legal_hold;
        try {
          decode(legal_hold, iter->second);
          dump_header(s, "x-amz-object-lock-legal-hold",legal_hold.get_status());
        } catch (buffer::error& err) {
          ldpp_dout(this, 0) << "ERROR: failed to decode RGWObjectLegalHold" << dendl;
        }
      }
    }
  }

done:
  for (riter = response_attrs.begin(); riter != response_attrs.end();
       ++riter) {
    dump_header(s, riter->first, riter->second);
  }

  if (op_ret == -ERR_NOT_MODIFIED) {
      end_header(s, this);
  } else {
      if (!content_type)
          content_type = "binary/octet-stream";

      end_header(s, this, content_type);
  }

  if (metadata_bl.length()) {
    dump_body(s, metadata_bl);
  }
  sent_header = true;

send_data:
  if (get_data && !op_ret) {
    int r = dump_body(s, bl.c_str() + bl_ofs, bl_len);
    if (r < 0)
      return r;
  }

  return 0;
}

rgw: reject control characters in response-header actions

S3 GetObject permits overriding response header values, but those inputs
need to be validated to insure only characters that are valid in an HTTP
header value are present.

Credit: Initial vulnerability discovery by William Bowling (@wcbowling)
Credit: Further vulnerability discovery by Robin H. Johnson <rjohnson@digitalocean.com>
Signed-off-by: Robin H. Johnson <rjohnson@digitalocean.com>


int RGWGetObj_ObjStore_S3::send_response_data(bufferlist& bl, off_t bl_ofs,
					      off_t bl_len)
{
  const char *content_type = NULL;
  string content_type_str;
  map<string, string> response_attrs;
  map<string, string>::iterator riter;
  bufferlist metadata_bl;

  if (sent_header)
    goto send_data;

  if (custom_http_ret) {
    set_req_state_err(s, 0);
    dump_errno(s, custom_http_ret);
  } else {
    set_req_state_err(s, (partial_content && !op_ret) ? STATUS_PARTIAL_CONTENT
                  : op_ret);
    dump_errno(s);
  }

  if (op_ret)
    goto done;

  if (range_str)
    dump_range(s, start, end, s->obj_size);

  if (s->system_request &&
      s->info.args.exists(RGW_SYS_PARAM_PREFIX "prepend-metadata")) {

    dump_header(s, "Rgwx-Object-Size", (long long)total_len);

    if (rgwx_stat) {
      /*
       * in this case, we're not returning the object's content, only the prepended
       * extra metadata
       */
      total_len = 0;
    }

    /* JSON encode object metadata */
    JSONFormatter jf;
    jf.open_object_section("obj_metadata");
    encode_json("attrs", attrs, &jf);
    utime_t ut(lastmod);
    encode_json("mtime", ut, &jf);
    jf.close_section();
    stringstream ss;
    jf.flush(ss);
    metadata_bl.append(ss.str());
    dump_header(s, "Rgwx-Embedded-Metadata-Len", metadata_bl.length());
    total_len += metadata_bl.length();
  }

  if (s->system_request && !real_clock::is_zero(lastmod)) {
    /* we end up dumping mtime in two different methods, a bit redundant */
    dump_epoch_header(s, "Rgwx-Mtime", lastmod);
    uint64_t pg_ver = 0;
    int r = decode_attr_bl_single_value(attrs, RGW_ATTR_PG_VER, &pg_ver, (uint64_t)0);
    if (r < 0) {
      ldout(s->cct, 0) << "ERROR: failed to decode pg ver attr, ignoring" << dendl;
    }
    dump_header(s, "Rgwx-Obj-PG-Ver", pg_ver);

    uint32_t source_zone_short_id = 0;
    r = decode_attr_bl_single_value(attrs, RGW_ATTR_SOURCE_ZONE, &source_zone_short_id, (uint32_t)0);
    if (r < 0) {
      ldout(s->cct, 0) << "ERROR: failed to decode pg ver attr, ignoring" << dendl;
    }
    if (source_zone_short_id != 0) {
      dump_header(s, "Rgwx-Source-Zone-Short-Id", source_zone_short_id);
    }
  }

  for (auto &it : crypt_http_responses)
    dump_header(s, it.first, it.second);

  dump_content_length(s, total_len);
  dump_last_modified(s, lastmod);
  dump_header_if_nonempty(s, "x-amz-version-id", version_id);
  if (attrs.find(RGW_ATTR_APPEND_PART_NUM) != attrs.end()) {
    dump_header(s, "x-rgw-object-type", "Appendable");
    dump_header(s, "x-rgw-next-append-position", s->obj_size);
  } else {
    dump_header(s, "x-rgw-object-type", "Normal");
  }

  if (! op_ret) {
    if (! lo_etag.empty()) {
      /* Handle etag of Swift API's large objects (DLO/SLO). It's entirerly
       * legit to perform GET on them through S3 API. In such situation,
       * a client should receive the composited content with corresponding
       * etag value. */
      dump_etag(s, lo_etag);
    } else {
      auto iter = attrs.find(RGW_ATTR_ETAG);
      if (iter != attrs.end()) {
        dump_etag(s, iter->second.to_str());
      }
    }

    for (struct response_attr_param *p = resp_attr_params; p->param; p++) {
      bool exists;
      string val = s->info.args.get(p->param, &exists);
      if (exists) {
	/* reject unauthenticated response header manipulation, see
	 * https://docs.aws.amazon.com/AmazonS3/latest/API/API_GetObject.html */
	if (s->auth.identity->is_anonymous()) {
	  return -ERR_INVALID_REQUEST;
	}
        /* HTTP specification says no control characters should be present in
         * header values: https://tools.ietf.org/html/rfc7230#section-3.2
         *      field-vchar    = VCHAR / obs-text
         *
         * Failure to validate this permits a CRLF injection in HTTP headers,
         * whereas S3 GetObject only permits specific headers.
         */
        if(str_has_cntrl(val)) {
          /* TODO: return a more distinct error in future;
           * stating what the problem is */
          return -ERR_INVALID_REQUEST;
        }

	if (strcmp(p->param, "response-content-type") != 0) {
	  response_attrs[p->http_attr] = val;
	} else {
	  content_type_str = val;
	  content_type = content_type_str.c_str();
	}
      }
    }

    for (auto iter = attrs.begin(); iter != attrs.end(); ++iter) {
      const char *name = iter->first.c_str();
      map<string, string>::iterator aiter = rgw_to_http_attrs.find(name);
      if (aiter != rgw_to_http_attrs.end()) {
        if (response_attrs.count(aiter->second) == 0) {
          /* Was not already overridden by a response param. */

          size_t len = iter->second.length();
          string s(iter->second.c_str(), len);
          while (len && !s[len - 1]) {
            --len;
            s.resize(len);
          }
          response_attrs[aiter->second] = s;
        }
      } else if (iter->first.compare(RGW_ATTR_CONTENT_TYPE) == 0) {
        /* Special handling for content_type. */
        if (!content_type) {
          content_type_str = rgw_bl_str(iter->second);
          content_type = content_type_str.c_str();
        }
      } else if (strcmp(name, RGW_ATTR_SLO_UINDICATOR) == 0) {
        // this attr has an extra length prefix from encode() in prior versions
        dump_header(s, "X-Object-Meta-Static-Large-Object", "True");
      } else if (strncmp(name, RGW_ATTR_META_PREFIX,
			 sizeof(RGW_ATTR_META_PREFIX)-1) == 0) {
        /* User custom metadata. */
        name += sizeof(RGW_ATTR_PREFIX) - 1;
        dump_header(s, name, iter->second);
      } else if (iter->first.compare(RGW_ATTR_TAGS) == 0) {
        RGWObjTags obj_tags;
        try{
          auto it = iter->second.cbegin();
          obj_tags.decode(it);
        } catch (buffer::error &err) {
          ldout(s->cct,0) << "Error caught buffer::error couldn't decode TagSet " << dendl;
        }
        dump_header(s, RGW_AMZ_TAG_COUNT, obj_tags.count());
      } else if (iter->first.compare(RGW_ATTR_OBJECT_RETENTION) == 0 && get_retention){
        RGWObjectRetention retention;
        try {
          decode(retention, iter->second);
          dump_header(s, "x-amz-object-lock-mode", retention.get_mode());
          dump_time_header(s, "x-amz-object-lock-retain-until-date", retention.get_retain_until_date());
        } catch (buffer::error& err) {
          ldpp_dout(this, 0) << "ERROR: failed to decode RGWObjectRetention" << dendl;
        }
      } else if (iter->first.compare(RGW_ATTR_OBJECT_LEGAL_HOLD) == 0 && get_legal_hold) {
        RGWObjectLegalHold legal_hold;
        try {
          decode(legal_hold, iter->second);
          dump_header(s, "x-amz-object-lock-legal-hold",legal_hold.get_status());
        } catch (buffer::error& err) {
          ldpp_dout(this, 0) << "ERROR: failed to decode RGWObjectLegalHold" << dendl;
        }
      }
    }
  }

done:
  for (riter = response_attrs.begin(); riter != response_attrs.end();
       ++riter) {
    dump_header(s, riter->first, riter->second);
  }

  if (op_ret == -ERR_NOT_MODIFIED) {
      end_header(s, this);
  } else {
      if (!content_type)
          content_type = "binary/octet-stream";

      end_header(s, this, content_type);
  }

  if (metadata_bl.length()) {
    dump_body(s, metadata_bl);
  }
  sent_header = true;

send_data:
  if (get_data && !op_ret) {
    int r = dump_body(s, bl.c_str() + bl_ofs, bl_len);
    if (r < 0)
      return r;
  }

  return 0;
}


gtTileContig(TIFFRGBAImage* img, uint32* raster, uint32 w, uint32 h)
{
    TIFF* tif = img->tif;
    tileContigRoutine put = img->put.contig;
    uint32 col, row, y, rowstoread;
    tmsize_t pos;
    uint32 tw, th;
    unsigned char* buf = NULL;
    int32 fromskew, toskew;
    uint32 nrow;
    int ret = 1, flip;
    uint32 this_tw, tocol;
    int32 this_toskew, leftmost_toskew;
    int32 leftmost_fromskew;
    uint32 leftmost_tw;
    tmsize_t bufsize;

    bufsize = TIFFTileSize(tif);
    if (bufsize == 0) {
        TIFFErrorExt(tif->tif_clientdata, TIFFFileName(tif), "%s", "No space for tile buffer");
        return (0);
    }

    TIFFGetField(tif, TIFFTAG_TILEWIDTH, &tw);
    TIFFGetField(tif, TIFFTAG_TILELENGTH, &th);

    flip = setorientation(img);
    if (flip & FLIP_VERTICALLY) {
	    y = h - 1;
	    toskew = -(int32)(tw + w);
    }
    else {
	    y = 0;
	    toskew = -(int32)(tw - w);
    }

    /*
     *	Leftmost tile is clipped on left side if col_offset > 0.
     */
    leftmost_fromskew = img->col_offset % tw;
    leftmost_tw = tw - leftmost_fromskew;
    leftmost_toskew = toskew + leftmost_fromskew;
    for (row = 0; ret != 0 && row < h; row += nrow)
    {
        rowstoread = th - (row + img->row_offset) % th;
    	nrow = (row + rowstoread > h ? h - row : rowstoread);
	fromskew = leftmost_fromskew;
	this_tw = leftmost_tw;
	this_toskew = leftmost_toskew;
	tocol = 0;
	col = img->col_offset;
	while (tocol < w)
        {
	    if (_TIFFReadTileAndAllocBuffer(tif, (void**) &buf, bufsize, col,
			     row+img->row_offset, 0, 0)==(tmsize_t)(-1) &&
                (buf == NULL || img->stoponerr))
            {
                ret = 0;
                break;
            }
            pos = ((row+img->row_offset) % th) * TIFFTileRowSize(tif) + \
		   ((tmsize_t) fromskew * img->samplesperpixel);
	    if (tocol + this_tw > w)
	    {
		/*
		 * Rightmost tile is clipped on right side.
		 */
		fromskew = tw - (w - tocol);
		this_tw = tw - fromskew;
		this_toskew = toskew + fromskew;
	    }
	    (*put)(img, raster+y*w+tocol, tocol, y, this_tw, nrow, fromskew, this_toskew, buf + pos);
	    tocol += this_tw;
	    col += this_tw;
	    /*
	     * After the leftmost tile, tiles are no longer clipped on left side.
	     */
	    fromskew = 0;
	    this_tw = tw;
	    this_toskew = toskew;
	}

        y += ((flip & FLIP_VERTICALLY) ? -(int32) nrow : (int32) nrow);
    }
    _TIFFfree(buf);

    if (flip & FLIP_HORIZONTALLY) {
	    uint32 line;

	    for (line = 0; line < h; line++) {
		    uint32 *left = raster + (line * w);
		    uint32 *right = left + w - 1;

		    while ( left < right ) {
			    uint32 temp = *left;
			    *left = *right;
			    *right = temp;
			    left++;
				right--;
		    }
	    }
    }

    return (ret);
}

gtTileContig(): check Tile width for overflow

fixes #211


gtTileContig(TIFFRGBAImage* img, uint32* raster, uint32 w, uint32 h)
{
    TIFF* tif = img->tif;
    tileContigRoutine put = img->put.contig;
    uint32 col, row, y, rowstoread;
    tmsize_t pos;
    uint32 tw, th;
    unsigned char* buf = NULL;
    int32 fromskew, toskew;
    uint32 nrow;
    int ret = 1, flip;
    uint32 this_tw, tocol;
    int32 this_toskew, leftmost_toskew;
    int32 leftmost_fromskew;
    uint32 leftmost_tw;
    tmsize_t bufsize;

    bufsize = TIFFTileSize(tif);
    if (bufsize == 0) {
        TIFFErrorExt(tif->tif_clientdata, TIFFFileName(tif), "%s", "No space for tile buffer");
        return (0);
    }

    TIFFGetField(tif, TIFFTAG_TILEWIDTH, &tw);
    TIFFGetField(tif, TIFFTAG_TILELENGTH, &th);

    flip = setorientation(img);
    if (flip & FLIP_VERTICALLY) {
        if ((tw + w) > INT_MAX) {
            TIFFErrorExt(tif->tif_clientdata, TIFFFileName(tif), "%s", "unsupported tile size (too wide)");
            return (0);
        }
        y = h - 1;
        toskew = -(int32)(tw + w);
    }
    else {
        if (tw > (INT_MAX + w)) {
            TIFFErrorExt(tif->tif_clientdata, TIFFFileName(tif), "%s", "unsupported tile size (too wide)");
            return (0);
        }
        y = 0;
        toskew = -(int32)(tw - w);
    }

    /*
     *	Leftmost tile is clipped on left side if col_offset > 0.
     */
    leftmost_fromskew = img->col_offset % tw;
    leftmost_tw = tw - leftmost_fromskew;
    leftmost_toskew = toskew + leftmost_fromskew;
    for (row = 0; ret != 0 && row < h; row += nrow)
    {
        rowstoread = th - (row + img->row_offset) % th;
    	nrow = (row + rowstoread > h ? h - row : rowstoread);
	fromskew = leftmost_fromskew;
	this_tw = leftmost_tw;
	this_toskew = leftmost_toskew;
	tocol = 0;
	col = img->col_offset;
	while (tocol < w)
        {
	    if (_TIFFReadTileAndAllocBuffer(tif, (void**) &buf, bufsize, col,
			     row+img->row_offset, 0, 0)==(tmsize_t)(-1) &&
                (buf == NULL || img->stoponerr))
            {
                ret = 0;
                break;
            }
            pos = ((row+img->row_offset) % th) * TIFFTileRowSize(tif) + \
		   ((tmsize_t) fromskew * img->samplesperpixel);
	    if (tocol + this_tw > w)
	    {
		/*
		 * Rightmost tile is clipped on right side.
		 */
		fromskew = tw - (w - tocol);
		this_tw = tw - fromskew;
		this_toskew = toskew + fromskew;
	    }
	    (*put)(img, raster+y*w+tocol, tocol, y, this_tw, nrow, fromskew, this_toskew, buf + pos);
	    tocol += this_tw;
	    col += this_tw;
	    /*
	     * After the leftmost tile, tiles are no longer clipped on left side.
	     */
	    fromskew = 0;
	    this_tw = tw;
	    this_toskew = toskew;
	}

        y += ((flip & FLIP_VERTICALLY) ? -(int32) nrow : (int32) nrow);
    }
    _TIFFfree(buf);

    if (flip & FLIP_HORIZONTALLY) {
	    uint32 line;

	    for (line = 0; line < h; line++) {
		    uint32 *left = raster + (line * w);
		    uint32 *right = left + w - 1;

		    while ( left < right ) {
			    uint32 temp = *left;
			    *left = *right;
			    *right = temp;
			    left++;
				right--;
		    }
	    }
    }

    return (ret);
}


static void io_async_task_func(struct callback_head *cb)
{
	struct io_kiocb *req = container_of(cb, struct io_kiocb, task_work);
	struct async_poll *apoll = req->apoll;
	struct io_ring_ctx *ctx = req->ctx;

	trace_io_uring_task_run(req->ctx, req->opcode, req->user_data);

	if (io_poll_rewait(req, &apoll->poll)) {
		spin_unlock_irq(&ctx->completion_lock);
		return;
	}

	/* If req is still hashed, it cannot have been canceled. Don't check. */
	if (hash_hashed(&req->hash_node))
		hash_del(&req->hash_node);

	io_poll_remove_double(req, apoll->double_poll);
	spin_unlock_irq(&ctx->completion_lock);

	if (!READ_ONCE(apoll->poll.canceled))
		__io_req_task_submit(req);
	else
		__io_req_task_cancel(req, -ECANCELED);

	kfree(apoll->double_poll);
	kfree(apoll);
}

io_uring: hold 'ctx' reference around task_work queue + execute

We're holding the request reference, but we need to go one higher
to ensure that the ctx remains valid after the request has finished.
If the ring is closed with pending task_work inflight, and the
given io_kiocb finishes sync during issue, then we need a reference
to the ring itself around the task_work execution cycle.

Cc: stable@vger.kernel.org # v5.7+
Reported-by: syzbot+9b260fc33297966f5a8e@syzkaller.appspotmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>


static void io_async_task_func(struct callback_head *cb)
{
	struct io_kiocb *req = container_of(cb, struct io_kiocb, task_work);
	struct async_poll *apoll = req->apoll;
	struct io_ring_ctx *ctx = req->ctx;

	trace_io_uring_task_run(req->ctx, req->opcode, req->user_data);

	if (io_poll_rewait(req, &apoll->poll)) {
		spin_unlock_irq(&ctx->completion_lock);
		percpu_ref_put(&ctx->refs);
		return;
	}

	/* If req is still hashed, it cannot have been canceled. Don't check. */
	if (hash_hashed(&req->hash_node))
		hash_del(&req->hash_node);

	io_poll_remove_double(req, apoll->double_poll);
	spin_unlock_irq(&ctx->completion_lock);

	if (!READ_ONCE(apoll->poll.canceled))
		__io_req_task_submit(req);
	else
		__io_req_task_cancel(req, -ECANCELED);

	percpu_ref_put(&ctx->refs);
	kfree(apoll->double_poll);
	kfree(apoll);
}


private int
mget(struct magic_set *ms, const unsigned char *s, struct magic *m,
    size_t nbytes, size_t o, unsigned int cont_level, int mode, int text,
    int flip, int recursion_level, int *printed_something,
    int *need_separator, int *returnval)
{
	uint32_t soffset, offset = ms->offset;
	uint32_t count = m->str_range;
	int rv, oneed_separator;
	char *sbuf, *rbuf;
	union VALUETYPE *p = &ms->ms_value;
	struct mlist ml;

	if (recursion_level >= 20) {
		file_error(ms, 0, "recursion nesting exceeded");
		return -1;
	}

	if (mcopy(ms, p, m->type, m->flag & INDIR, s, (uint32_t)(offset + o),
	    (uint32_t)nbytes, count) == -1)
		return -1;

	if ((ms->flags & MAGIC_DEBUG) != 0) {
		fprintf(stderr, "mget(type=%d, flag=%x, offset=%u, o=%zu, "
		    "nbytes=%zu, count=%u)\n", m->type, m->flag, offset, o,
		    nbytes, count);
		mdebug(offset, (char *)(void *)p, sizeof(union VALUETYPE));
	}

	if (m->flag & INDIR) {
		int off = m->in_offset;
		if (m->in_op & FILE_OPINDIRECT) {
			const union VALUETYPE *q = CAST(const union VALUETYPE *,
			    ((const void *)(s + offset + off)));
			switch (cvt_flip(m->in_type, flip)) {
			case FILE_BYTE:
				off = q->b;
				break;
			case FILE_SHORT:
				off = q->h;
				break;
			case FILE_BESHORT:
				off = (short)((q->hs[0]<<8)|(q->hs[1]));
				break;
			case FILE_LESHORT:
				off = (short)((q->hs[1]<<8)|(q->hs[0]));
				break;
			case FILE_LONG:
				off = q->l;
				break;
			case FILE_BELONG:
			case FILE_BEID3:
				off = (int32_t)((q->hl[0]<<24)|(q->hl[1]<<16)|
						 (q->hl[2]<<8)|(q->hl[3]));
				break;
			case FILE_LEID3:
			case FILE_LELONG:
				off = (int32_t)((q->hl[3]<<24)|(q->hl[2]<<16)|
						 (q->hl[1]<<8)|(q->hl[0]));
				break;
			case FILE_MELONG:
				off = (int32_t)((q->hl[1]<<24)|(q->hl[0]<<16)|
						 (q->hl[3]<<8)|(q->hl[2]));
				break;
			}
			if ((ms->flags & MAGIC_DEBUG) != 0)
				fprintf(stderr, "indirect offs=%u\n", off);
		}
		switch (cvt_flip(m->in_type, flip)) {
		case FILE_BYTE:
			if (nbytes < (offset + 1))
				return 0;
			if (off) {
				switch (m->in_op & FILE_OPS_MASK) {
				case FILE_OPAND:
					offset = p->b & off;
					break;
				case FILE_OPOR:
					offset = p->b | off;
					break;
				case FILE_OPXOR:
					offset = p->b ^ off;
					break;
				case FILE_OPADD:
					offset = p->b + off;
					break;
				case FILE_OPMINUS:
					offset = p->b - off;
					break;
				case FILE_OPMULTIPLY:
					offset = p->b * off;
					break;
				case FILE_OPDIVIDE:
					offset = p->b / off;
					break;
				case FILE_OPMODULO:
					offset = p->b % off;
					break;
				}
			} else
				offset = p->b;
			if (m->in_op & FILE_OPINVERSE)
				offset = ~offset;
			break;
		case FILE_BESHORT:
			if (nbytes < (offset + 2))
				return 0;
			if (off) {
				switch (m->in_op & FILE_OPS_MASK) {
				case FILE_OPAND:
					offset = (short)((p->hs[0]<<8)|
							 (p->hs[1])) &
						 off;
					break;
				case FILE_OPOR:
					offset = (short)((p->hs[0]<<8)|
							 (p->hs[1])) |
						 off;
					break;
				case FILE_OPXOR:
					offset = (short)((p->hs[0]<<8)|
							 (p->hs[1])) ^
						 off;
					break;
				case FILE_OPADD:
					offset = (short)((p->hs[0]<<8)|
							 (p->hs[1])) +
						 off;
					break;
				case FILE_OPMINUS:
					offset = (short)((p->hs[0]<<8)|
							 (p->hs[1])) -
						 off;
					break;
				case FILE_OPMULTIPLY:
					offset = (short)((p->hs[0]<<8)|
							 (p->hs[1])) *
						 off;
					break;
				case FILE_OPDIVIDE:
					offset = (short)((p->hs[0]<<8)|
							 (p->hs[1])) /
						 off;
					break;
				case FILE_OPMODULO:
					offset = (short)((p->hs[0]<<8)|
							 (p->hs[1])) %
						 off;
					break;
				}
			} else
				offset = (short)((p->hs[0]<<8)|
						 (p->hs[1]));
			if (m->in_op & FILE_OPINVERSE)
				offset = ~offset;
			break;
		case FILE_LESHORT:
			if (nbytes < (offset + 2))
				return 0;
			if (off) {
				switch (m->in_op & FILE_OPS_MASK) {
				case FILE_OPAND:
					offset = (short)((p->hs[1]<<8)|
							 (p->hs[0])) &
						 off;
					break;
				case FILE_OPOR:
					offset = (short)((p->hs[1]<<8)|
							 (p->hs[0])) |
						 off;
					break;
				case FILE_OPXOR:
					offset = (short)((p->hs[1]<<8)|
							 (p->hs[0])) ^
						 off;
					break;
				case FILE_OPADD:
					offset = (short)((p->hs[1]<<8)|
							 (p->hs[0])) +
						 off;
					break;
				case FILE_OPMINUS:
					offset = (short)((p->hs[1]<<8)|
							 (p->hs[0])) -
						 off;
					break;
				case FILE_OPMULTIPLY:
					offset = (short)((p->hs[1]<<8)|
							 (p->hs[0])) *
						 off;
					break;
				case FILE_OPDIVIDE:
					offset = (short)((p->hs[1]<<8)|
							 (p->hs[0])) /
						 off;
					break;
				case FILE_OPMODULO:
					offset = (short)((p->hs[1]<<8)|
							 (p->hs[0])) %
						 off;
					break;
				}
			} else
				offset = (short)((p->hs[1]<<8)|
						 (p->hs[0]));
			if (m->in_op & FILE_OPINVERSE)
				offset = ~offset;
			break;
		case FILE_SHORT:
			if (nbytes < (offset + 2))
				return 0;
			if (off) {
				switch (m->in_op & FILE_OPS_MASK) {
				case FILE_OPAND:
					offset = p->h & off;
					break;
				case FILE_OPOR:
					offset = p->h | off;
					break;
				case FILE_OPXOR:
					offset = p->h ^ off;
					break;
				case FILE_OPADD:
					offset = p->h + off;
					break;
				case FILE_OPMINUS:
					offset = p->h - off;
					break;
				case FILE_OPMULTIPLY:
					offset = p->h * off;
					break;
				case FILE_OPDIVIDE:
					offset = p->h / off;
					break;
				case FILE_OPMODULO:
					offset = p->h % off;
					break;
				}
			}
			else
				offset = p->h;
			if (m->in_op & FILE_OPINVERSE)
				offset = ~offset;
			break;
		case FILE_BELONG:
		case FILE_BEID3:
			if (nbytes < (offset + 4))
				return 0;
			if (off) {
				switch (m->in_op & FILE_OPS_MASK) {
				case FILE_OPAND:
					offset = (int32_t)((p->hl[0]<<24)|
							 (p->hl[1]<<16)|
							 (p->hl[2]<<8)|
							 (p->hl[3])) &
						 off;
					break;
				case FILE_OPOR:
					offset = (int32_t)((p->hl[0]<<24)|
							 (p->hl[1]<<16)|
							 (p->hl[2]<<8)|
							 (p->hl[3])) |
						 off;
					break;
				case FILE_OPXOR:
					offset = (int32_t)((p->hl[0]<<24)|
							 (p->hl[1]<<16)|
							 (p->hl[2]<<8)|
							 (p->hl[3])) ^
						 off;
					break;
				case FILE_OPADD:
					offset = (int32_t)((p->hl[0]<<24)|
							 (p->hl[1]<<16)|
							 (p->hl[2]<<8)|
							 (p->hl[3])) +
						 off;
					break;
				case FILE_OPMINUS:
					offset = (int32_t)((p->hl[0]<<24)|
							 (p->hl[1]<<16)|
							 (p->hl[2]<<8)|
							 (p->hl[3])) -
						 off;
					break;
				case FILE_OPMULTIPLY:
					offset = (int32_t)((p->hl[0]<<24)|
							 (p->hl[1]<<16)|
							 (p->hl[2]<<8)|
							 (p->hl[3])) *
						 off;
					break;
				case FILE_OPDIVIDE:
					offset = (int32_t)((p->hl[0]<<24)|
							 (p->hl[1]<<16)|
							 (p->hl[2]<<8)|
							 (p->hl[3])) /
						 off;
					break;
				case FILE_OPMODULO:
					offset = (int32_t)((p->hl[0]<<24)|
							 (p->hl[1]<<16)|
							 (p->hl[2]<<8)|
							 (p->hl[3])) %
						 off;
					break;
				}
			} else
				offset = (int32_t)((p->hl[0]<<24)|
						 (p->hl[1]<<16)|
						 (p->hl[2]<<8)|
						 (p->hl[3]));
			if (m->in_op & FILE_OPINVERSE)
				offset = ~offset;
			break;
		case FILE_LELONG:
		case FILE_LEID3:
			if (nbytes < (offset + 4))
				return 0;
			if (off) {
				switch (m->in_op & FILE_OPS_MASK) {
				case FILE_OPAND:
					offset = (int32_t)((p->hl[3]<<24)|
							 (p->hl[2]<<16)|
							 (p->hl[1]<<8)|
							 (p->hl[0])) &
						 off;
					break;
				case FILE_OPOR:
					offset = (int32_t)((p->hl[3]<<24)|
							 (p->hl[2]<<16)|
							 (p->hl[1]<<8)|
							 (p->hl[0])) |
						 off;
					break;
				case FILE_OPXOR:
					offset = (int32_t)((p->hl[3]<<24)|
							 (p->hl[2]<<16)|
							 (p->hl[1]<<8)|
							 (p->hl[0])) ^
						 off;
					break;
				case FILE_OPADD:
					offset = (int32_t)((p->hl[3]<<24)|
							 (p->hl[2]<<16)|
							 (p->hl[1]<<8)|
							 (p->hl[0])) +
						 off;
					break;
				case FILE_OPMINUS:
					offset = (int32_t)((p->hl[3]<<24)|
							 (p->hl[2]<<16)|
							 (p->hl[1]<<8)|
							 (p->hl[0])) -
						 off;
					break;
				case FILE_OPMULTIPLY:
					offset = (int32_t)((p->hl[3]<<24)|
							 (p->hl[2]<<16)|
							 (p->hl[1]<<8)|
							 (p->hl[0])) *
						 off;
					break;
				case FILE_OPDIVIDE:
					offset = (int32_t)((p->hl[3]<<24)|
							 (p->hl[2]<<16)|
							 (p->hl[1]<<8)|
							 (p->hl[0])) /
						 off;
					break;
				case FILE_OPMODULO:
					offset = (int32_t)((p->hl[3]<<24)|
							 (p->hl[2]<<16)|
							 (p->hl[1]<<8)|
							 (p->hl[0])) %
						 off;
					break;
				}
			} else
				offset = (int32_t)((p->hl[3]<<24)|
						 (p->hl[2]<<16)|
						 (p->hl[1]<<8)|
						 (p->hl[0]));
			if (m->in_op & FILE_OPINVERSE)
				offset = ~offset;
			break;
		case FILE_MELONG:
			if (nbytes < (offset + 4))
				return 0;
			if (off) {
				switch (m->in_op & FILE_OPS_MASK) {
				case FILE_OPAND:
					offset = (int32_t)((p->hl[1]<<24)|
							 (p->hl[0]<<16)|
							 (p->hl[3]<<8)|
							 (p->hl[2])) &
						 off;
					break;
				case FILE_OPOR:
					offset = (int32_t)((p->hl[1]<<24)|
							 (p->hl[0]<<16)|
							 (p->hl[3]<<8)|
							 (p->hl[2])) |
						 off;
					break;
				case FILE_OPXOR:
					offset = (int32_t)((p->hl[1]<<24)|
							 (p->hl[0]<<16)|
							 (p->hl[3]<<8)|
							 (p->hl[2])) ^
						 off;
					break;
				case FILE_OPADD:
					offset = (int32_t)((p->hl[1]<<24)|
							 (p->hl[0]<<16)|
							 (p->hl[3]<<8)|
							 (p->hl[2])) +
						 off;
					break;
				case FILE_OPMINUS:
					offset = (int32_t)((p->hl[1]<<24)|
							 (p->hl[0]<<16)|
							 (p->hl[3]<<8)|
							 (p->hl[2])) -
						 off;
					break;
				case FILE_OPMULTIPLY:
					offset = (int32_t)((p->hl[1]<<24)|
							 (p->hl[0]<<16)|
							 (p->hl[3]<<8)|
							 (p->hl[2])) *
						 off;
					break;
				case FILE_OPDIVIDE:
					offset = (int32_t)((p->hl[1]<<24)|
							 (p->hl[0]<<16)|
							 (p->hl[3]<<8)|
							 (p->hl[2])) /
						 off;
					break;
				case FILE_OPMODULO:
					offset = (int32_t)((p->hl[1]<<24)|
							 (p->hl[0]<<16)|
							 (p->hl[3]<<8)|
							 (p->hl[2])) %
						 off;
					break;
				}
			} else
				offset = (int32_t)((p->hl[1]<<24)|
						 (p->hl[0]<<16)|
						 (p->hl[3]<<8)|
						 (p->hl[2]));
			if (m->in_op & FILE_OPINVERSE)
				offset = ~offset;
			break;
		case FILE_LONG:
			if (nbytes < (offset + 4))
				return 0;
			if (off) {
				switch (m->in_op & FILE_OPS_MASK) {
				case FILE_OPAND:
					offset = p->l & off;
					break;
				case FILE_OPOR:
					offset = p->l | off;
					break;
				case FILE_OPXOR:
					offset = p->l ^ off;
					break;
				case FILE_OPADD:
					offset = p->l + off;
					break;
				case FILE_OPMINUS:
					offset = p->l - off;
					break;
				case FILE_OPMULTIPLY:
					offset = p->l * off;
					break;
				case FILE_OPDIVIDE:
					offset = p->l / off;
					break;
				case FILE_OPMODULO:
					offset = p->l % off;
					break;
				}
			} else
				offset = p->l;
			if (m->in_op & FILE_OPINVERSE)
				offset = ~offset;
			break;
		}

		switch (cvt_flip(m->in_type, flip)) {
		case FILE_LEID3:
		case FILE_BEID3:
			offset = ((((offset >>  0) & 0x7f) <<  0) |
				 (((offset >>  8) & 0x7f) <<  7) |
				 (((offset >> 16) & 0x7f) << 14) |
				 (((offset >> 24) & 0x7f) << 21)) + 10;
			break;
		default:
			break;
		}

		if (m->flag & INDIROFFADD) {
			offset += ms->c.li[cont_level-1].off;
			if (offset == 0) {
				if ((ms->flags & MAGIC_DEBUG) != 0)
					fprintf(stderr,
					    "indirect *zero* offset\n");
				return 0;
			}
			if ((ms->flags & MAGIC_DEBUG) != 0)
				fprintf(stderr, "indirect +offs=%u\n", offset);
		}
		if (mcopy(ms, p, m->type, 0, s, offset, nbytes, count) == -1)
			return -1;
		ms->offset = offset;

		if ((ms->flags & MAGIC_DEBUG) != 0) {
			mdebug(offset, (char *)(void *)p,
			    sizeof(union VALUETYPE));
		}
	}

	/* Verify we have enough data to match magic type */
	switch (m->type) {
	case FILE_BYTE:
		if (nbytes < (offset + 1)) /* should alway be true */
			return 0;
		break;

	case FILE_SHORT:
	case FILE_BESHORT:
	case FILE_LESHORT:
		if (nbytes < (offset + 2))
			return 0;
		break;

	case FILE_LONG:
	case FILE_BELONG:
	case FILE_LELONG:
	case FILE_MELONG:
	case FILE_DATE:
	case FILE_BEDATE:
	case FILE_LEDATE:
	case FILE_MEDATE:
	case FILE_LDATE:
	case FILE_BELDATE:
	case FILE_LELDATE:
	case FILE_MELDATE:
	case FILE_FLOAT:
	case FILE_BEFLOAT:
	case FILE_LEFLOAT:
		if (nbytes < (offset + 4))
			return 0;
		break;

	case FILE_DOUBLE:
	case FILE_BEDOUBLE:
	case FILE_LEDOUBLE:
		if (nbytes < (offset + 8))
			return 0;
		break;

	case FILE_STRING:
	case FILE_PSTRING:
	case FILE_SEARCH:
		if (nbytes < (offset + m->vallen))
			return 0;
		break;

	case FILE_REGEX:
		if (nbytes < offset)
			return 0;
		break;

	case FILE_INDIRECT:
		if (nbytes < offset)
			return 0;
		sbuf = ms->o.buf;
		soffset = ms->offset;
		ms->o.buf = NULL;
		ms->offset = 0;
		rv = file_softmagic(ms, s + offset, nbytes - offset,
		    BINTEST, text);
		if ((ms->flags & MAGIC_DEBUG) != 0)
			fprintf(stderr, "indirect @offs=%u[%d]\n", offset, rv);
		rbuf = ms->o.buf;
		ms->o.buf = sbuf;
		ms->offset = soffset;
		if (rv == 1) {
	  	if ((ms->flags & (MAGIC_MIME|MAGIC_APPLE)) == 0 &&
			    file_printf(ms, m->desc, offset) == -1)
			return -1;
			if (file_printf(ms, "%s", rbuf) == -1)
				return -1;
			free(rbuf);
		}
		return rv;

	case FILE_USE:
		if (nbytes < offset)
			return 0;
		sbuf = m->value.s;
		if (*sbuf == '^') {
			sbuf++;
			flip = !flip;
		}
		if (file_magicfind(ms, sbuf, &ml) == -1) {
			file_error(ms, 0, "cannot find entry `%s'", sbuf);
			return -1;
		}

		oneed_separator = *need_separator;
		if (m->flag & NOSPACE)
			*need_separator = 0;
		rv = match(ms, ml.magic, ml.nmagic, s, nbytes, offset + o,
		    mode, text, flip, recursion_level, printed_something,
		    need_separator, returnval);
		if (rv != 1)
		    *need_separator = oneed_separator;
		return rv;

	case FILE_NAME:
		if (file_printf(ms, "%s", m->desc) == -1)
			return -1;
		return 1;
	case FILE_DEFAULT:	/* nothing to check */
	default:
		break;
	}
	if (!mconvert(ms, m, flip))
		return 0;

Fixed bug #64830 mimetype detection segfaults on mp3 file


private int
mget(struct magic_set *ms, const unsigned char *s, struct magic *m,
    size_t nbytes, size_t o, unsigned int cont_level, int mode, int text,
    int flip, int recursion_level, int *printed_something,
    int *need_separator, int *returnval)
{
	uint32_t soffset, offset = ms->offset;
	uint32_t count = m->str_range;
	int rv, oneed_separator;
	char *sbuf, *rbuf;
	union VALUETYPE *p = &ms->ms_value;
	struct mlist ml;

	if (recursion_level >= 20) {
		file_error(ms, 0, "recursion nesting exceeded");
		return -1;
	}

	if (mcopy(ms, p, m->type, m->flag & INDIR, s, (uint32_t)(offset + o),
	    (uint32_t)nbytes, count) == -1)
		return -1;

	if ((ms->flags & MAGIC_DEBUG) != 0) {
		fprintf(stderr, "mget(type=%d, flag=%x, offset=%u, o=%zu, "
		    "nbytes=%zu, count=%u)\n", m->type, m->flag, offset, o,
		    nbytes, count);
		mdebug(offset, (char *)(void *)p, sizeof(union VALUETYPE));
	}

	if (m->flag & INDIR) {
		int off = m->in_offset;
		if (m->in_op & FILE_OPINDIRECT) {
			const union VALUETYPE *q = CAST(const union VALUETYPE *,
			    ((const void *)(s + offset + off)));
			switch (cvt_flip(m->in_type, flip)) {
			case FILE_BYTE:
				off = q->b;
				break;
			case FILE_SHORT:
				off = q->h;
				break;
			case FILE_BESHORT:
				off = (short)((q->hs[0]<<8)|(q->hs[1]));
				break;
			case FILE_LESHORT:
				off = (short)((q->hs[1]<<8)|(q->hs[0]));
				break;
			case FILE_LONG:
				off = q->l;
				break;
			case FILE_BELONG:
			case FILE_BEID3:
				off = (int32_t)((q->hl[0]<<24)|(q->hl[1]<<16)|
						 (q->hl[2]<<8)|(q->hl[3]));
				break;
			case FILE_LEID3:
			case FILE_LELONG:
				off = (int32_t)((q->hl[3]<<24)|(q->hl[2]<<16)|
						 (q->hl[1]<<8)|(q->hl[0]));
				break;
			case FILE_MELONG:
				off = (int32_t)((q->hl[1]<<24)|(q->hl[0]<<16)|
						 (q->hl[3]<<8)|(q->hl[2]));
				break;
			}
			if ((ms->flags & MAGIC_DEBUG) != 0)
				fprintf(stderr, "indirect offs=%u\n", off);
		}
		switch (cvt_flip(m->in_type, flip)) {
		case FILE_BYTE:
			if (nbytes < (offset + 1))
				return 0;
			if (off) {
				switch (m->in_op & FILE_OPS_MASK) {
				case FILE_OPAND:
					offset = p->b & off;
					break;
				case FILE_OPOR:
					offset = p->b | off;
					break;
				case FILE_OPXOR:
					offset = p->b ^ off;
					break;
				case FILE_OPADD:
					offset = p->b + off;
					break;
				case FILE_OPMINUS:
					offset = p->b - off;
					break;
				case FILE_OPMULTIPLY:
					offset = p->b * off;
					break;
				case FILE_OPDIVIDE:
					offset = p->b / off;
					break;
				case FILE_OPMODULO:
					offset = p->b % off;
					break;
				}
			} else
				offset = p->b;
			if (m->in_op & FILE_OPINVERSE)
				offset = ~offset;
			break;
		case FILE_BESHORT:
			if (nbytes < (offset + 2))
				return 0;
			if (off) {
				switch (m->in_op & FILE_OPS_MASK) {
				case FILE_OPAND:
					offset = (short)((p->hs[0]<<8)|
							 (p->hs[1])) &
						 off;
					break;
				case FILE_OPOR:
					offset = (short)((p->hs[0]<<8)|
							 (p->hs[1])) |
						 off;
					break;
				case FILE_OPXOR:
					offset = (short)((p->hs[0]<<8)|
							 (p->hs[1])) ^
						 off;
					break;
				case FILE_OPADD:
					offset = (short)((p->hs[0]<<8)|
							 (p->hs[1])) +
						 off;
					break;
				case FILE_OPMINUS:
					offset = (short)((p->hs[0]<<8)|
							 (p->hs[1])) -
						 off;
					break;
				case FILE_OPMULTIPLY:
					offset = (short)((p->hs[0]<<8)|
							 (p->hs[1])) *
						 off;
					break;
				case FILE_OPDIVIDE:
					offset = (short)((p->hs[0]<<8)|
							 (p->hs[1])) /
						 off;
					break;
				case FILE_OPMODULO:
					offset = (short)((p->hs[0]<<8)|
							 (p->hs[1])) %
						 off;
					break;
				}
			} else
				offset = (short)((p->hs[0]<<8)|
						 (p->hs[1]));
			if (m->in_op & FILE_OPINVERSE)
				offset = ~offset;
			break;
		case FILE_LESHORT:
			if (nbytes < (offset + 2))
				return 0;
			if (off) {
				switch (m->in_op & FILE_OPS_MASK) {
				case FILE_OPAND:
					offset = (short)((p->hs[1]<<8)|
							 (p->hs[0])) &
						 off;
					break;
				case FILE_OPOR:
					offset = (short)((p->hs[1]<<8)|
							 (p->hs[0])) |
						 off;
					break;
				case FILE_OPXOR:
					offset = (short)((p->hs[1]<<8)|
							 (p->hs[0])) ^
						 off;
					break;
				case FILE_OPADD:
					offset = (short)((p->hs[1]<<8)|
							 (p->hs[0])) +
						 off;
					break;
				case FILE_OPMINUS:
					offset = (short)((p->hs[1]<<8)|
							 (p->hs[0])) -
						 off;
					break;
				case FILE_OPMULTIPLY:
					offset = (short)((p->hs[1]<<8)|
							 (p->hs[0])) *
						 off;
					break;
				case FILE_OPDIVIDE:
					offset = (short)((p->hs[1]<<8)|
							 (p->hs[0])) /
						 off;
					break;
				case FILE_OPMODULO:
					offset = (short)((p->hs[1]<<8)|
							 (p->hs[0])) %
						 off;
					break;
				}
			} else
				offset = (short)((p->hs[1]<<8)|
						 (p->hs[0]));
			if (m->in_op & FILE_OPINVERSE)
				offset = ~offset;
			break;
		case FILE_SHORT:
			if (nbytes < (offset + 2))
				return 0;
			if (off) {
				switch (m->in_op & FILE_OPS_MASK) {
				case FILE_OPAND:
					offset = p->h & off;
					break;
				case FILE_OPOR:
					offset = p->h | off;
					break;
				case FILE_OPXOR:
					offset = p->h ^ off;
					break;
				case FILE_OPADD:
					offset = p->h + off;
					break;
				case FILE_OPMINUS:
					offset = p->h - off;
					break;
				case FILE_OPMULTIPLY:
					offset = p->h * off;
					break;
				case FILE_OPDIVIDE:
					offset = p->h / off;
					break;
				case FILE_OPMODULO:
					offset = p->h % off;
					break;
				}
			}
			else
				offset = p->h;
			if (m->in_op & FILE_OPINVERSE)
				offset = ~offset;
			break;
		case FILE_BELONG:
		case FILE_BEID3:
			if (nbytes < (offset + 4))
				return 0;
			if (off) {
				switch (m->in_op & FILE_OPS_MASK) {
				case FILE_OPAND:
					offset = (int32_t)((p->hl[0]<<24)|
							 (p->hl[1]<<16)|
							 (p->hl[2]<<8)|
							 (p->hl[3])) &
						 off;
					break;
				case FILE_OPOR:
					offset = (int32_t)((p->hl[0]<<24)|
							 (p->hl[1]<<16)|
							 (p->hl[2]<<8)|
							 (p->hl[3])) |
						 off;
					break;
				case FILE_OPXOR:
					offset = (int32_t)((p->hl[0]<<24)|
							 (p->hl[1]<<16)|
							 (p->hl[2]<<8)|
							 (p->hl[3])) ^
						 off;
					break;
				case FILE_OPADD:
					offset = (int32_t)((p->hl[0]<<24)|
							 (p->hl[1]<<16)|
							 (p->hl[2]<<8)|
							 (p->hl[3])) +
						 off;
					break;
				case FILE_OPMINUS:
					offset = (int32_t)((p->hl[0]<<24)|
							 (p->hl[1]<<16)|
							 (p->hl[2]<<8)|
							 (p->hl[3])) -
						 off;
					break;
				case FILE_OPMULTIPLY:
					offset = (int32_t)((p->hl[0]<<24)|
							 (p->hl[1]<<16)|
							 (p->hl[2]<<8)|
							 (p->hl[3])) *
						 off;
					break;
				case FILE_OPDIVIDE:
					offset = (int32_t)((p->hl[0]<<24)|
							 (p->hl[1]<<16)|
							 (p->hl[2]<<8)|
							 (p->hl[3])) /
						 off;
					break;
				case FILE_OPMODULO:
					offset = (int32_t)((p->hl[0]<<24)|
							 (p->hl[1]<<16)|
							 (p->hl[2]<<8)|
							 (p->hl[3])) %
						 off;
					break;
				}
			} else
				offset = (int32_t)((p->hl[0]<<24)|
						 (p->hl[1]<<16)|
						 (p->hl[2]<<8)|
						 (p->hl[3]));
			if (m->in_op & FILE_OPINVERSE)
				offset = ~offset;
			break;
		case FILE_LELONG:
		case FILE_LEID3:
			if (nbytes < (offset + 4))
				return 0;
			if (off) {
				switch (m->in_op & FILE_OPS_MASK) {
				case FILE_OPAND:
					offset = (int32_t)((p->hl[3]<<24)|
							 (p->hl[2]<<16)|
							 (p->hl[1]<<8)|
							 (p->hl[0])) &
						 off;
					break;
				case FILE_OPOR:
					offset = (int32_t)((p->hl[3]<<24)|
							 (p->hl[2]<<16)|
							 (p->hl[1]<<8)|
							 (p->hl[0])) |
						 off;
					break;
				case FILE_OPXOR:
					offset = (int32_t)((p->hl[3]<<24)|
							 (p->hl[2]<<16)|
							 (p->hl[1]<<8)|
							 (p->hl[0])) ^
						 off;
					break;
				case FILE_OPADD:
					offset = (int32_t)((p->hl[3]<<24)|
							 (p->hl[2]<<16)|
							 (p->hl[1]<<8)|
							 (p->hl[0])) +
						 off;
					break;
				case FILE_OPMINUS:
					offset = (int32_t)((p->hl[3]<<24)|
							 (p->hl[2]<<16)|
							 (p->hl[1]<<8)|
							 (p->hl[0])) -
						 off;
					break;
				case FILE_OPMULTIPLY:
					offset = (int32_t)((p->hl[3]<<24)|
							 (p->hl[2]<<16)|
							 (p->hl[1]<<8)|
							 (p->hl[0])) *
						 off;
					break;
				case FILE_OPDIVIDE:
					offset = (int32_t)((p->hl[3]<<24)|
							 (p->hl[2]<<16)|
							 (p->hl[1]<<8)|
							 (p->hl[0])) /
						 off;
					break;
				case FILE_OPMODULO:
					offset = (int32_t)((p->hl[3]<<24)|
							 (p->hl[2]<<16)|
							 (p->hl[1]<<8)|
							 (p->hl[0])) %
						 off;
					break;
				}
			} else
				offset = (int32_t)((p->hl[3]<<24)|
						 (p->hl[2]<<16)|
						 (p->hl[1]<<8)|
						 (p->hl[0]));
			if (m->in_op & FILE_OPINVERSE)
				offset = ~offset;
			break;
		case FILE_MELONG:
			if (nbytes < (offset + 4))
				return 0;
			if (off) {
				switch (m->in_op & FILE_OPS_MASK) {
				case FILE_OPAND:
					offset = (int32_t)((p->hl[1]<<24)|
							 (p->hl[0]<<16)|
							 (p->hl[3]<<8)|
							 (p->hl[2])) &
						 off;
					break;
				case FILE_OPOR:
					offset = (int32_t)((p->hl[1]<<24)|
							 (p->hl[0]<<16)|
							 (p->hl[3]<<8)|
							 (p->hl[2])) |
						 off;
					break;
				case FILE_OPXOR:
					offset = (int32_t)((p->hl[1]<<24)|
							 (p->hl[0]<<16)|
							 (p->hl[3]<<8)|
							 (p->hl[2])) ^
						 off;
					break;
				case FILE_OPADD:
					offset = (int32_t)((p->hl[1]<<24)|
							 (p->hl[0]<<16)|
							 (p->hl[3]<<8)|
							 (p->hl[2])) +
						 off;
					break;
				case FILE_OPMINUS:
					offset = (int32_t)((p->hl[1]<<24)|
							 (p->hl[0]<<16)|
							 (p->hl[3]<<8)|
							 (p->hl[2])) -
						 off;
					break;
				case FILE_OPMULTIPLY:
					offset = (int32_t)((p->hl[1]<<24)|
							 (p->hl[0]<<16)|
							 (p->hl[3]<<8)|
							 (p->hl[2])) *
						 off;
					break;
				case FILE_OPDIVIDE:
					offset = (int32_t)((p->hl[1]<<24)|
							 (p->hl[0]<<16)|
							 (p->hl[3]<<8)|
							 (p->hl[2])) /
						 off;
					break;
				case FILE_OPMODULO:
					offset = (int32_t)((p->hl[1]<<24)|
							 (p->hl[0]<<16)|
							 (p->hl[3]<<8)|
							 (p->hl[2])) %
						 off;
					break;
				}
			} else
				offset = (int32_t)((p->hl[1]<<24)|
						 (p->hl[0]<<16)|
						 (p->hl[3]<<8)|
						 (p->hl[2]));
			if (m->in_op & FILE_OPINVERSE)
				offset = ~offset;
			break;
		case FILE_LONG:
			if (nbytes < (offset + 4))
				return 0;
			if (off) {
				switch (m->in_op & FILE_OPS_MASK) {
				case FILE_OPAND:
					offset = p->l & off;
					break;
				case FILE_OPOR:
					offset = p->l | off;
					break;
				case FILE_OPXOR:
					offset = p->l ^ off;
					break;
				case FILE_OPADD:
					offset = p->l + off;
					break;
				case FILE_OPMINUS:
					offset = p->l - off;
					break;
				case FILE_OPMULTIPLY:
					offset = p->l * off;
					break;
				case FILE_OPDIVIDE:
					offset = p->l / off;
					break;
				case FILE_OPMODULO:
					offset = p->l % off;
					break;
				}
			} else
				offset = p->l;
			if (m->in_op & FILE_OPINVERSE)
				offset = ~offset;
			break;
		}

		switch (cvt_flip(m->in_type, flip)) {
		case FILE_LEID3:
		case FILE_BEID3:
			offset = ((((offset >>  0) & 0x7f) <<  0) |
				 (((offset >>  8) & 0x7f) <<  7) |
				 (((offset >> 16) & 0x7f) << 14) |
				 (((offset >> 24) & 0x7f) << 21)) + 10;
			break;
		default:
			break;
		}

		if (m->flag & INDIROFFADD) {
			offset += ms->c.li[cont_level-1].off;
			if (offset == 0) {
				if ((ms->flags & MAGIC_DEBUG) != 0)
					fprintf(stderr,
					    "indirect *zero* offset\n");
				return 0;
			}
			if ((ms->flags & MAGIC_DEBUG) != 0)
				fprintf(stderr, "indirect +offs=%u\n", offset);
		}
		if (mcopy(ms, p, m->type, 0, s, offset, nbytes, count) == -1)
			return -1;
		ms->offset = offset;

		if ((ms->flags & MAGIC_DEBUG) != 0) {
			mdebug(offset, (char *)(void *)p,
			    sizeof(union VALUETYPE));
		}
	}

	/* Verify we have enough data to match magic type */
	switch (m->type) {
	case FILE_BYTE:
		if (nbytes < (offset + 1)) /* should alway be true */
			return 0;
		break;

	case FILE_SHORT:
	case FILE_BESHORT:
	case FILE_LESHORT:
		if (nbytes < (offset + 2))
			return 0;
		break;

	case FILE_LONG:
	case FILE_BELONG:
	case FILE_LELONG:
	case FILE_MELONG:
	case FILE_DATE:
	case FILE_BEDATE:
	case FILE_LEDATE:
	case FILE_MEDATE:
	case FILE_LDATE:
	case FILE_BELDATE:
	case FILE_LELDATE:
	case FILE_MELDATE:
	case FILE_FLOAT:
	case FILE_BEFLOAT:
	case FILE_LEFLOAT:
		if (nbytes < (offset + 4))
			return 0;
		break;

	case FILE_DOUBLE:
	case FILE_BEDOUBLE:
	case FILE_LEDOUBLE:
		if (nbytes < (offset + 8))
			return 0;
		break;

	case FILE_STRING:
	case FILE_PSTRING:
	case FILE_SEARCH:
		if (nbytes < (offset + m->vallen))
			return 0;
		break;

	case FILE_REGEX:
		if (nbytes < offset)
			return 0;
		break;

	case FILE_INDIRECT:
		if (nbytes < offset)
			return 0;
		sbuf = ms->o.buf;
		soffset = ms->offset;
		ms->o.buf = NULL;
		ms->offset = 0;
		rv = file_softmagic(ms, s + offset, nbytes - offset,
		    BINTEST, text);
		if ((ms->flags & MAGIC_DEBUG) != 0)
			fprintf(stderr, "indirect @offs=%u[%d]\n", offset, rv);
		rbuf = ms->o.buf;
		ms->o.buf = sbuf;
		ms->offset = soffset;
		if (rv == 1) {
	  	if ((ms->flags & (MAGIC_MIME|MAGIC_APPLE)) == 0 &&
			    file_printf(ms, m->desc, offset) == -1)
			return -1;
			if (file_printf(ms, "%s", rbuf) == -1)
				return -1;
			efree(rbuf);
		}
		return rv;

	case FILE_USE:
		if (nbytes < offset)
			return 0;
		sbuf = m->value.s;
		if (*sbuf == '^') {
			sbuf++;
			flip = !flip;
		}
		if (file_magicfind(ms, sbuf, &ml) == -1) {
			file_error(ms, 0, "cannot find entry `%s'", sbuf);
			return -1;
		}

		oneed_separator = *need_separator;
		if (m->flag & NOSPACE)
			*need_separator = 0;
		rv = match(ms, ml.magic, ml.nmagic, s, nbytes, offset + o,
		    mode, text, flip, recursion_level, printed_something,
		    need_separator, returnval);
		if (rv != 1)
		    *need_separator = oneed_separator;
		return rv;

	case FILE_NAME:
		if (file_printf(ms, "%s", m->desc) == -1)
			return -1;
		return 1;
	case FILE_DEFAULT:	/* nothing to check */
	default:
		break;
	}
	if (!mconvert(ms, m, flip))
		return 0;


ImagingFliDecode(Imaging im, ImagingCodecState state, UINT8 *buf, Py_ssize_t bytes) {
    UINT8 *ptr;
    int framesize;
    int c, chunks, advance;
    int l, lines;
    int i, j, x = 0, y, ymax;

    /* If not even the chunk size is present, we'd better leave */

    if (bytes < 4) {
        return 0;
    }

    /* We don't decode anything unless we have a full chunk in the
       input buffer */

    ptr = buf;

    framesize = I32(ptr);
    if (framesize < I32(ptr)) {
        return 0;
    }

    /* Make sure this is a frame chunk.  The Python driver takes
       case of other chunk types. */

    if (bytes < 8) {
        state->errcode = IMAGING_CODEC_OVERRUN;
        return -1;
    }
    if (I16(ptr + 4) != 0xF1FA) {
        state->errcode = IMAGING_CODEC_UNKNOWN;
        return -1;
    }

    chunks = I16(ptr + 6);
    ptr += 16;
    bytes -= 16;

    /* Process subchunks */
    for (c = 0; c < chunks; c++) {
        UINT8 *data;
        if (bytes < 10) {
            state->errcode = IMAGING_CODEC_OVERRUN;
            return -1;
        }
        data = ptr + 6;
        switch (I16(ptr + 4)) {
            case 4:
            case 11:
                /* FLI COLOR chunk */
                break; /* ignored; handled by Python code */
            case 7:
                /* FLI SS2 chunk (word delta) */
                /* OOB ok, we've got 4 bytes min on entry */
                lines = I16(data);
                data += 2;
                for (l = y = 0; l < lines && y < state->ysize; l++, y++) {
                    UINT8 *local_buf = (UINT8 *)im->image[y];
                    int p, packets;
                    ERR_IF_DATA_OOB(2)
                    packets = I16(data);
                    data += 2;
                    while (packets & 0x8000) {
                        /* flag word */
                        if (packets & 0x4000) {
                            y += 65536 - packets; /* skip lines */
                            if (y >= state->ysize) {
                                state->errcode = IMAGING_CODEC_OVERRUN;
                                return -1;
                            }
                            local_buf = (UINT8 *)im->image[y];
                        } else {
                            /* store last byte (used if line width is odd) */
                            local_buf[state->xsize - 1] = (UINT8)packets;
                        }
                        ERR_IF_DATA_OOB(2)
                        packets = I16(data);
                        data += 2;
                    }
                    for (p = x = 0; p < packets; p++) {
                        ERR_IF_DATA_OOB(2)
                        x += data[0]; /* pixel skip */
                        if (data[1] >= 128) {
                            ERR_IF_DATA_OOB(4)
                            i = 256 - data[1]; /* run */
                            if (x + i + i > state->xsize) {
                                break;
                            }
                            for (j = 0; j < i; j++) {
                                local_buf[x++] = data[2];
                                local_buf[x++] = data[3];
                            }
                            data += 2 + 2;
                        } else {
                            i = 2 * (int)data[1]; /* chunk */
                            if (x + i > state->xsize) {
                                break;
                            }
                            ERR_IF_DATA_OOB(2 + i)
                            memcpy(local_buf + x, data + 2, i);
                            data += 2 + i;
                            x += i;
                        }
                    }
                    if (p < packets) {
                        break; /* didn't process all packets */
                    }
                }
                if (l < lines) {
                    /* didn't process all lines */
                    state->errcode = IMAGING_CODEC_OVERRUN;
                    return -1;
                }
                break;
            case 12:
                /* FLI LC chunk (byte delta) */
                /* OOB Check ok, we have 4 bytes min here */
                y = I16(data);
                ymax = y + I16(data + 2);
                data += 4;
                for (; y < ymax && y < state->ysize; y++) {
                    UINT8 *out = (UINT8 *)im->image[y];
                    ERR_IF_DATA_OOB(1)
                    int p, packets = *data++;
                    for (p = x = 0; p < packets; p++, x += i) {
                        ERR_IF_DATA_OOB(2)
                        x += data[0]; /* skip pixels */
                        if (data[1] & 0x80) {
                            i = 256 - data[1]; /* run */
                            if (x + i > state->xsize) {
                                break;
                            }
                            ERR_IF_DATA_OOB(3)
                            memset(out + x, data[2], i);
                            data += 3;
                        } else {
                            i = data[1]; /* chunk */
                            if (x + i > state->xsize) {
                                break;
                            }
                            ERR_IF_DATA_OOB(2 + i)
                            memcpy(out + x, data + 2, i);
                            data += i + 2;
                        }
                    }
                    if (p < packets) {
                        break; /* didn't process all packets */
                    }
                }
                if (y < ymax) {
                    /* didn't process all lines */
                    state->errcode = IMAGING_CODEC_OVERRUN;
                    return -1;
                }
                break;
            case 13:
                /* FLI BLACK chunk */
                for (y = 0; y < state->ysize; y++) {
                    memset(im->image[y], 0, state->xsize);
                }
                break;
            case 15:
                /* FLI BRUN chunk */
                /* OOB, ok, we've got 4 bytes min on entry */
                for (y = 0; y < state->ysize; y++) {
                    UINT8 *out = (UINT8 *)im->image[y];
                    data += 1; /* ignore packetcount byte */
                    for (x = 0; x < state->xsize; x += i) {
                        ERR_IF_DATA_OOB(2)
                        if (data[0] & 0x80) {
                            i = 256 - data[0];
                            if (x + i > state->xsize) {
                                break; /* safety first */
                            }
                            ERR_IF_DATA_OOB(i + 1)
                            memcpy(out + x, data + 1, i);
                            data += i + 1;
                        } else {
                            i = data[0];
                            if (x + i > state->xsize) {
                                break; /* safety first */
                            }
                            memset(out + x, data[1], i);
                            data += 2;
                        }
                    }
                    if (x != state->xsize) {
                        /* didn't unpack whole line */
                        state->errcode = IMAGING_CODEC_OVERRUN;
                        return -1;
                    }
                }
                break;
            case 16:
                /* COPY chunk */
                if (state->xsize > bytes / state->ysize) {
                    /* not enough data for frame */
                    return ptr - buf; /* bytes consumed */
                }
                for (y = 0; y < state->ysize; y++) {
                    UINT8 *local_buf = (UINT8 *)im->image[y];
                    memcpy(local_buf, data, state->xsize);
                    data += state->xsize;
                }
                break;
            case 18:
                /* PSTAMP chunk */
                break; /* ignored */
            default:
                /* unknown chunk */
                /* printf("unknown FLI/FLC chunk: %d\n", I16(ptr+4)); */
                state->errcode = IMAGING_CODEC_UNKNOWN;
                return -1;
        }
        advance = I32(ptr);
        if (advance < 0 || advance > bytes) {
            state->errcode = IMAGING_CODEC_OVERRUN;
            return -1;
        }
        ptr += advance;
        bytes -= advance;
    }

    return -1; /* end of frame */
}

Fix FLI DOS -- CVE-2021-28676

* FliDecode did not properly check that the block advance was
  non-zero, potentally leading to an infinite loop on load.
* This dates to the PIL Fork
* Found with oss-fuzz


ImagingFliDecode(Imaging im, ImagingCodecState state, UINT8 *buf, Py_ssize_t bytes) {
    UINT8 *ptr;
    int framesize;
    int c, chunks, advance;
    int l, lines;
    int i, j, x = 0, y, ymax;

    /* If not even the chunk size is present, we'd better leave */

    if (bytes < 4) {
        return 0;
    }

    /* We don't decode anything unless we have a full chunk in the
       input buffer */

    ptr = buf;

    framesize = I32(ptr);
    if (framesize < I32(ptr)) {
        return 0;
    }

    /* Make sure this is a frame chunk.  The Python driver takes
       case of other chunk types. */

    if (bytes < 8) {
        state->errcode = IMAGING_CODEC_OVERRUN;
        return -1;
    }
    if (I16(ptr + 4) != 0xF1FA) {
        state->errcode = IMAGING_CODEC_UNKNOWN;
        return -1;
    }

    chunks = I16(ptr + 6);
    ptr += 16;
    bytes -= 16;

    /* Process subchunks */
    for (c = 0; c < chunks; c++) {
        UINT8 *data;
        if (bytes < 10) {
            state->errcode = IMAGING_CODEC_OVERRUN;
            return -1;
        }
        data = ptr + 6;
        switch (I16(ptr + 4)) {
            case 4:
            case 11:
                /* FLI COLOR chunk */
                break; /* ignored; handled by Python code */
            case 7:
                /* FLI SS2 chunk (word delta) */
                /* OOB ok, we've got 4 bytes min on entry */
                lines = I16(data);
                data += 2;
                for (l = y = 0; l < lines && y < state->ysize; l++, y++) {
                    UINT8 *local_buf = (UINT8 *)im->image[y];
                    int p, packets;
                    ERR_IF_DATA_OOB(2)
                    packets = I16(data);
                    data += 2;
                    while (packets & 0x8000) {
                        /* flag word */
                        if (packets & 0x4000) {
                            y += 65536 - packets; /* skip lines */
                            if (y >= state->ysize) {
                                state->errcode = IMAGING_CODEC_OVERRUN;
                                return -1;
                            }
                            local_buf = (UINT8 *)im->image[y];
                        } else {
                            /* store last byte (used if line width is odd) */
                            local_buf[state->xsize - 1] = (UINT8)packets;
                        }
                        ERR_IF_DATA_OOB(2)
                        packets = I16(data);
                        data += 2;
                    }
                    for (p = x = 0; p < packets; p++) {
                        ERR_IF_DATA_OOB(2)
                        x += data[0]; /* pixel skip */
                        if (data[1] >= 128) {
                            ERR_IF_DATA_OOB(4)
                            i = 256 - data[1]; /* run */
                            if (x + i + i > state->xsize) {
                                break;
                            }
                            for (j = 0; j < i; j++) {
                                local_buf[x++] = data[2];
                                local_buf[x++] = data[3];
                            }
                            data += 2 + 2;
                        } else {
                            i = 2 * (int)data[1]; /* chunk */
                            if (x + i > state->xsize) {
                                break;
                            }
                            ERR_IF_DATA_OOB(2 + i)
                            memcpy(local_buf + x, data + 2, i);
                            data += 2 + i;
                            x += i;
                        }
                    }
                    if (p < packets) {
                        break; /* didn't process all packets */
                    }
                }
                if (l < lines) {
                    /* didn't process all lines */
                    state->errcode = IMAGING_CODEC_OVERRUN;
                    return -1;
                }
                break;
            case 12:
                /* FLI LC chunk (byte delta) */
                /* OOB Check ok, we have 4 bytes min here */
                y = I16(data);
                ymax = y + I16(data + 2);
                data += 4;
                for (; y < ymax && y < state->ysize; y++) {
                    UINT8 *out = (UINT8 *)im->image[y];
                    ERR_IF_DATA_OOB(1)
                    int p, packets = *data++;
                    for (p = x = 0; p < packets; p++, x += i) {
                        ERR_IF_DATA_OOB(2)
                        x += data[0]; /* skip pixels */
                        if (data[1] & 0x80) {
                            i = 256 - data[1]; /* run */
                            if (x + i > state->xsize) {
                                break;
                            }
                            ERR_IF_DATA_OOB(3)
                            memset(out + x, data[2], i);
                            data += 3;
                        } else {
                            i = data[1]; /* chunk */
                            if (x + i > state->xsize) {
                                break;
                            }
                            ERR_IF_DATA_OOB(2 + i)
                            memcpy(out + x, data + 2, i);
                            data += i + 2;
                        }
                    }
                    if (p < packets) {
                        break; /* didn't process all packets */
                    }
                }
                if (y < ymax) {
                    /* didn't process all lines */
                    state->errcode = IMAGING_CODEC_OVERRUN;
                    return -1;
                }
                break;
            case 13:
                /* FLI BLACK chunk */
                for (y = 0; y < state->ysize; y++) {
                    memset(im->image[y], 0, state->xsize);
                }
                break;
            case 15:
                /* FLI BRUN chunk */
                /* OOB, ok, we've got 4 bytes min on entry */
                for (y = 0; y < state->ysize; y++) {
                    UINT8 *out = (UINT8 *)im->image[y];
                    data += 1; /* ignore packetcount byte */
                    for (x = 0; x < state->xsize; x += i) {
                        ERR_IF_DATA_OOB(2)
                        if (data[0] & 0x80) {
                            i = 256 - data[0];
                            if (x + i > state->xsize) {
                                break; /* safety first */
                            }
                            ERR_IF_DATA_OOB(i + 1)
                            memcpy(out + x, data + 1, i);
                            data += i + 1;
                        } else {
                            i = data[0];
                            if (x + i > state->xsize) {
                                break; /* safety first */
                            }
                            memset(out + x, data[1], i);
                            data += 2;
                        }
                    }
                    if (x != state->xsize) {
                        /* didn't unpack whole line */
                        state->errcode = IMAGING_CODEC_OVERRUN;
                        return -1;
                    }
                }
                break;
            case 16:
                /* COPY chunk */
                if (state->xsize > bytes / state->ysize) {
                    /* not enough data for frame */
                    return ptr - buf; /* bytes consumed */
                }
                for (y = 0; y < state->ysize; y++) {
                    UINT8 *local_buf = (UINT8 *)im->image[y];
                    memcpy(local_buf, data, state->xsize);
                    data += state->xsize;
                }
                break;
            case 18:
                /* PSTAMP chunk */
                break; /* ignored */
            default:
                /* unknown chunk */
                /* printf("unknown FLI/FLC chunk: %d\n", I16(ptr+4)); */
                state->errcode = IMAGING_CODEC_UNKNOWN;
                return -1;
        }
        advance = I32(ptr);
        if (advance == 0 ) {
            // If there's no advance, we're in in infinite loop
            state->errcode = IMAGING_CODEC_BROKEN;
            return -1;
        }
        if (advance < 0 || advance > bytes) {
            state->errcode = IMAGING_CODEC_OVERRUN;
            return -1;
        }
        ptr += advance;
        bytes -= advance;
    }

    return -1; /* end of frame */
}