From c7c1a0e3537b692196c15ea764b789f601b15850 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Matej=20Mu=C5=BEila?= Date: Wed, 28 Jun 2023 14:05:50 +0200 Subject: [PATCH] (CVE-2023-26965) 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 (cherry picked from commit ec8ef90c1f573c9eb1f17d6a056aa0015f184acf) --- tools/tiffcrop.c | 45 ++++++++++++++------------------------------- 1 file changed, 14 insertions(+), 31 deletions(-) diff --git a/tools/tiffcrop.c b/tools/tiffcrop.c index c2688883..d9b91e4e 100644 --- a/tools/tiffcrop.c +++ b/tools/tiffcrop.c @@ -6103,9 +6103,7 @@ 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); @@ -6404,41 +6402,27 @@ 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) + /* +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) { - if( buffsize > 0xFFFFFFFFU - 3 ) - { - TIFFError("loadImage", "Unable to allocate/reallocate read buffer"); - return (-1); - } - read_buff = (unsigned char *)limitMalloc(buffsize + NUM_BUFF_OVERSIZE_BYTES); + _TIFFfree(read_buff); } - 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); } + read_buff = (unsigned char *)limitMalloc(buffsize + NUM_BUFF_OVERSIZE_BYTES); + if (!read_buff) { - TIFFError("loadImage", "Unable to allocate/reallocate read buffer"); + TIFFError("loadImage", "Unable to allocate read buffer" ); return (-1); } @@ -6446,7 +6430,6 @@ loadImage(TIFF* in, struct image_data *image, struct dump_opts *dump, unsigned c 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