PR #21344 opened by Timo Rothenpieler (BtbN) URL: https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/21344 Patch URL: https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/21344.patch (cherry picked from commit f6a95c7eb786f895812adaaa08d2fe91c4d4caf8) From 89b4e464dc8adf5a596738fe339b6d08b20fcf08 Mon Sep 17 00:00:00 2001 From: Timo Rothenpieler <timo@rothenpieler.org> Date: Wed, 31 Dec 2025 03:41:21 +0100 Subject: [PATCH] avformat/img2dec: reject input images too big to fit into a single packet Not entirely sure if it should instead use some entirely different approach here, given that images exceeding 2GB don't seem that crazy to me, but so far processing such images results in a heap overflow, since the size addition overflows and a much too small packet is allocated and its size never checked again when writing into it. Fixes #YWH-PGM40646-32 (cherry picked from commit f6a95c7eb786f895812adaaa08d2fe91c4d4caf8) --- libavformat/img2dec.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) diff --git a/libavformat/img2dec.c b/libavformat/img2dec.c index 7d173d8030..9f42dfdbb0 100644 --- a/libavformat/img2dec.c +++ b/libavformat/img2dec.c @@ -406,8 +406,10 @@ int ff_img_read_packet(AVFormatContext *s1, AVPacket *pkt) char filename_bytes[1024]; char *filename = filename_bytes; int i, res; - int size[3] = { 0 }, ret[3] = { 0 }; - AVIOContext *f[3] = { NULL }; + int ret[3] = { 0 }; + int64_t size[3] = { 0 }; + int64_t total_size; + AVIOContext *f[3] = { NULL }; AVCodecParameters *par = s1->streams[0]->codecpar; if (!s->is_pipe) { @@ -487,7 +489,17 @@ int ff_img_read_packet(AVFormatContext *s1, AVPacket *pkt) } } - res = av_new_packet(pkt, size[0] + size[1] + size[2]); + total_size = size[0]; + if (total_size > INT64_MAX - size[1]) + return AVERROR_INVALIDDATA; + total_size += size[1]; + if (total_size > INT64_MAX - size[2]) + return AVERROR_INVALIDDATA; + total_size += size[2]; + if (total_size > INT_MAX) + return AVERROR_INVALIDDATA; + + res = av_new_packet(pkt, total_size); if (res < 0) { goto fail; } -- 2.49.1