From ec8ef90c1f573c9eb1f17d6a056aa0015f184acf Mon Sep 17 00:00:00 2001 From: Su_Laus Date: Tue, 14 Feb 2023 20:43:43 +0100 Subject: [PATCH] tiffcrop: Do not reuse input buffer for subsequent images. Fix issue 527 Reuse of read_buff within loadImage() from previous image is quite unsafe, because other functions (like rotateImage() etc.) reallocate that buffer with different size without updating the local prev_readsize value. Closes #527 Upstream-Status: Backport [https://gitlab.com/libtiff/libtiff/-/commit/ec8ef90c1f573c9eb1f17d6a056aa0015f184acf] CVE: CVE-2023-26965 Signed-off-by: Hitendra Prajapati --- tools/tiffcrop.c | 47 +++++++++++++++-------------------------------- 1 file changed, 15 insertions(+), 32 deletions(-) diff --git a/tools/tiffcrop.c b/tools/tiffcrop.c index b811fbb..ce77c74 100644 --- a/tools/tiffcrop.c +++ b/tools/tiffcrop.c @@ -6066,9 +6066,7 @@ loadImage(TIFF* in, struct image_data *image, struct dump_opts *dump, unsigned c uint32_t tw = 0, tl = 0; /* Tile width and length */ tmsize_t tile_rowsize = 0; unsigned char *read_buff = NULL; - unsigned char *new_buff = NULL; int readunit = 0; - static tmsize_t prev_readsize = 0; TIFFGetFieldDefaulted(in, TIFFTAG_BITSPERSAMPLE, &bps); TIFFGetFieldDefaulted(in, TIFFTAG_SAMPLESPERPIXEL, &spp); @@ -6361,47 +6359,32 @@ loadImage(TIFF* in, struct image_data *image, struct dump_opts *dump, unsigned c } read_buff = *read_ptr; - /* +3 : add a few guard bytes since reverseSamples16bits() can read a bit */ - /* outside buffer */ - if (!read_buff) - { - if( buffsize > 0xFFFFFFFFU - 3 ) + /* +3 : add a few guard bytes since reverseSamples16bits() can read a bit + * outside buffer */ + /* Reuse of read_buff from previous image is quite unsafe, because other + * functions (like rotateImage() etc.) reallocate that buffer with different + * size without updating the local prev_readsize value. */ + if (read_buff) { - TIFFError("loadImage", "Unable to allocate/reallocate read buffer"); - return (-1); + _TIFFfree(read_buff); } - read_buff = (unsigned char *)limitMalloc(buffsize + NUM_BUFF_OVERSIZE_BYTES); - } - else + if (buffsize > 0xFFFFFFFFU - 3) { - if (prev_readsize < buffsize) - { - if( buffsize > 0xFFFFFFFFU - 3 ) - { - TIFFError("loadImage", "Unable to allocate/reallocate read buffer"); - return (-1); - } - new_buff = _TIFFrealloc(read_buff, buffsize + NUM_BUFF_OVERSIZE_BYTES); - if (!new_buff) - { - free (read_buff); - read_buff = (unsigned char *)limitMalloc(buffsize + NUM_BUFF_OVERSIZE_BYTES); - } - else - read_buff = new_buff; - } + TIFFError("loadImage", "Required read buffer size too large"); + return (-1); } - if (!read_buff) + read_buff = + (unsigned char *)limitMalloc(buffsize + NUM_BUFF_OVERSIZE_BYTES); + if (!read_buff) { - TIFFError("loadImage", "Unable to allocate/reallocate read buffer"); - return (-1); + TIFFError("loadImage", "Unable to allocate read buffer"); + return (-1); } read_buff[buffsize] = 0; read_buff[buffsize+1] = 0; read_buff[buffsize+2] = 0; - prev_readsize = buffsize; *read_ptr = read_buff; /* N.B. The read functions used copy separate plane data into a buffer as interleaved -- 2.25.1