diff options
| author | Dale Curtis <dalecurtis@chromium.org> | 2017-11-17 16:05:30 -0800 |
|---|---|---|
| committer | Michael Niedermayer <michael@niedermayer.cc> | 2017-11-21 03:13:03 +0100 |
| commit | 7010dd98b575d2e39fca947e609b85be7490b269 (patch) | |
| tree | a1c13f535fae2827a62bd3fd732cc7b4a94fddfa | |
| parent | 753074721bd414874d18c372c491bdc6323fa3bf (diff) | |
| download | ffmpeg-7010dd98b575d2e39fca947e609b85be7490b269.tar.gz | |
Fix undefined shift on assumed 8-bit input.
decode_user_data() attempts to create an integer |build|
value with 8 bits of spacing for 3 components. However
each component is an int32_t, so shifting each component
is undefined for values outside of the 8 bit range.
This patch simply clamps input to 8-bits per component
and prints out a warning that the values were clamped.
Signed-off-by: Dale Curtis <dalecurtis@chromium.org>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
| -rw-r--r-- | libavcodec/mpeg4videodec.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/libavcodec/mpeg4videodec.c b/libavcodec/mpeg4videodec.c index 76247c3b8c..11d4e08986 100644 --- a/libavcodec/mpeg4videodec.c +++ b/libavcodec/mpeg4videodec.c @@ -2153,8 +2153,15 @@ static int decode_user_data(Mpeg4DecContext *ctx, GetBitContext *gb) e = sscanf(buf, "FFmpeg v%d.%d.%d / libavcodec build: %d", &ver, &ver2, &ver3, &build); if (e != 4) { e = sscanf(buf, "Lavc%d.%d.%d", &ver, &ver2, &ver3) + 1; - if (e > 1) - build = (ver << 16) + (ver2 << 8) + ver3; + if (e > 1) { + if (ver > 0xFF || ver2 > 0xFF || ver3 > 0xFF) { + av_log(s->avctx, AV_LOG_WARNING, + "Unknown Lavc version string encountered, %d.%d.%d; " + "clamping sub-version values to 8-bits.\n", + ver, ver2, ver3); + } + build = ((ver & 0xFF) << 16) + ((ver2 & 0xFF) << 8) + (ver3 & 0xFF); + } } if (e != 4) { if (strcmp(buf, "ffmpeg") == 0) |