[FFmpeg-devel] [PATCH 2/2] avcodec/decode/ff_get_buffer: Check for overflow in FFALIGN()

Michael Niedermayer michael at niedermayer.cc
Wed Oct 14 18:53:08 EEST 2020


Fixes: signed integer overflow: 2147483647 + 64 cannot be represented in type 'int'
Fixes: 26218/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_CRI_fuzzer-5734075396259840

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
---
 libavcodec/decode.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/libavcodec/decode.c b/libavcodec/decode.c
index 3ef1ece25b..a0acfb54c5 100644
--- a/libavcodec/decode.c
+++ b/libavcodec/decode.c
@@ -1876,7 +1876,8 @@ int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
     int ret;
 
     if (avctx->codec_type == AVMEDIA_TYPE_VIDEO) {
-        if ((ret = av_image_check_size2(FFALIGN(avctx->width, STRIDE_ALIGN), avctx->height, avctx->max_pixels, AV_PIX_FMT_NONE, 0, avctx)) < 0 || avctx->pix_fmt<0) {
+        if ((unsigned)avctx->width > INT_MAX - STRIDE_ALIGN ||
+            (ret = av_image_check_size2(FFALIGN(avctx->width, STRIDE_ALIGN), avctx->height, avctx->max_pixels, AV_PIX_FMT_NONE, 0, avctx)) < 0 || avctx->pix_fmt<0) {
             av_log(avctx, AV_LOG_ERROR, "video_get_buffer: image parameters invalid\n");
             ret = AVERROR(EINVAL);
             goto fail;
-- 
2.17.1



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