PR #20268 opened by michaelni URL: https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/20268 Patch URL: https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/20268.patch
The setup code fow w,h,left,top is complex, the code using it also falls in at least 2 different classes, one using left/top the other not. To ensure no out of array access happens we add this clear check. Fixes: out of array access Fixes: 439261995/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_SANM_fuzzer-5383455572819968 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer <mich...@niedermayer.cc> >From 134fbfd1dcb59441e38d870ddd231772f4e8e127 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer <mich...@niedermayer.cc> Date: Sun, 17 Aug 2025 15:31:48 +0200 Subject: [PATCH] avcodec/sanm: Check w,h,left,top The setup code fow w,h,left,top is complex, the code using it also falls in at least 2 different classes, one using left/top the other not. To ensure no out of array access happens we add this clear check. Fixes: out of array access Fixes: 439261995/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_SANM_fuzzer-5383455572819968 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer <mich...@niedermayer.cc> --- libavcodec/sanm.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/libavcodec/sanm.c b/libavcodec/sanm.c index a066a864eb..9e99aa9dd9 100644 --- a/libavcodec/sanm.c +++ b/libavcodec/sanm.c @@ -1757,6 +1757,11 @@ static int process_frame_obj(SANMVideoContext *ctx, GetByteContext *gb) memset(ctx->fbuf, 0, ctx->frm0_size); } + if (w + FFMAX(left, 0) > ctx->avctx->width || h + FFMAX(top, 0) > ctx->avctx->height) { + avpriv_request_sample(ctx->avctx, "overly large frame\n"); + return AVERROR_PATCHWELCOME; + } + switch (codec) { case 1: case 3: -- 2.49.1 _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
