[FFmpeg-devel] [PATCH 09/11] avformat/pcm: Check block_align

Michael Niedermayer michael at niedermayer.cc
Tue Oct 20 23:56:17 EEST 2020


Fixes: signed integer overflow: 321 * 8746632 cannot be represented in type 'int'
Fixes: 26461/clusterfuzz-testcase-minimized-ffmpeg_dem_PVF_fuzzer-6326427831762944

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
---
 libavformat/pcm.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/libavformat/pcm.c b/libavformat/pcm.c
index 767bbd045a..1effc0b6f8 100644
--- a/libavformat/pcm.c
+++ b/libavformat/pcm.c
@@ -39,7 +39,11 @@ int ff_pcm_read_packet(AVFormatContext *s, AVPacket *pkt)
      * Clamp to RAW_SAMPLES if larger.
      */
     size = FFMAX(par->sample_rate/25, 1);
-    size = FFMIN(size, RAW_SAMPLES) * par->block_align;
+    if (par->block_align <= INT_MAX / RAW_SAMPLES) {
+        size = FFMIN(size, RAW_SAMPLES) * par->block_align;
+    } else {
+        size = par->block_align;
+    }
 
     ret = av_get_packet(s->pb, pkt, size);
 
-- 
2.17.1



More information about the ffmpeg-devel mailing list