diff options
| author | Andreas Rheinhardt <andreas.rheinhardt@outlook.com> | 2020-05-26 20:26:28 +0200 |
|---|---|---|
| committer | Andreas Rheinhardt <andreas.rheinhardt@outlook.com> | 2021-08-20 12:19:12 +0200 |
| commit | c83a7dd25fdf9636e7e5da3fad5e0d82035b9c86 (patch) | |
| tree | 6325e1d4b9b9c742d2e5bd3721c9a0fd6b80ac7c /libavcodec/h264_parser.c | |
| parent | 29bf3fafa0c46b6fbb205bc878fd3bcb6aa0d8cb (diff) | |
avcodec/h264_parser: Fix undefined left shift
Use an uint32_t for the NAL unit size of an AVC H.264 NAL unit instead
of an int as a left shift of a signed value is undefined behaviour
if the result doesn't fit into the target type.
Also make the log message never output negative lengths.
Fixes: left shift of 16711968 by 8 places cannot be represented in type 'int'
Fixes: 36601/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_H264_fuzzer-6581933285965824
Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
Diffstat (limited to 'libavcodec/h264_parser.c')
| -rw-r--r-- | libavcodec/h264_parser.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/libavcodec/h264_parser.c b/libavcodec/h264_parser.c index d3c56cc188..01ea016409 100644 --- a/libavcodec/h264_parser.c +++ b/libavcodec/h264_parser.c @@ -83,12 +83,13 @@ static int h264_find_frame_end(H264ParseContext *p, const uint8_t *buf, for (i = 0; i < buf_size; i++) { if (i >= next_avc) { - int nalsize = 0; + uint32_t nalsize = 0; i = next_avc; for (j = 0; j < p->nal_length_size; j++) nalsize = (nalsize << 8) | buf[i++]; - if (nalsize <= 0 || nalsize > buf_size - i) { - av_log(logctx, AV_LOG_ERROR, "AVC-parser: nal size %d remaining %d\n", nalsize, buf_size - i); + if (!nalsize || nalsize > buf_size - i) { + av_log(logctx, AV_LOG_ERROR, "AVC-parser: nal size %"PRIu32" " + "remaining %d\n", nalsize, buf_size - i); return buf_size; } next_avc = i + nalsize; |