[FFmpeg-devel] [PATCH] avformat/iamf_parse: increase PutBytes buffer when writing AAC extradata

James Almer jamrial at gmail.com
Sat May 10 18:51:09 EEST 2025


We may write up to 43 bits, so 5 bytes is not enough.

Fixes: Assertion n>=0 && n<=32 failed at ./libavcodec/get_bits.h:406
Fixes: 398527871/clusterfuzz-testcase-minimized-ffmpeg_dem_IAMF_fuzzer-6602025714647040

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: James Almer <jamrial at gmail.com>
---
 libavformat/iamf_parse.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavformat/iamf_parse.c b/libavformat/iamf_parse.c
index abedfdb066..14b69855c9 100644
--- a/libavformat/iamf_parse.c
+++ b/libavformat/iamf_parse.c
@@ -285,7 +285,7 @@ static int update_extradata(AVCodecParameters *codecpar)
         AV_WL16A(codecpar->extradata + 16, AV_RB16A(codecpar->extradata + 16)); // Byte swap Output Gain
         break;
     case AV_CODEC_ID_AAC: {
-        uint8_t buf[5];
+        uint8_t buf[6];
 
         init_put_bits(&pb, buf, sizeof(buf));
         ret = init_get_bits8(&gb, codecpar->extradata, codecpar->extradata_size);
-- 
2.49.0



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