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| author | James Almer <jamrial@gmail.com> | 2025-06-23 12:31:37 -0300 |
|---|---|---|
| committer | James Almer <jamrial@gmail.com> | 2025-06-24 14:41:43 -0300 |
| commit | a7beac704b1c3ba38c487e2fa367bb7a84a6c382 (patch) | |
| tree | 43efe9f10a30242a51f56f31982b76bc445488e5 | |
| parent | f67ca10f2e1e0c7aa53de12ebcc2c17ed63240a2 (diff) | |
| download | ffmpeg-a7beac704b1c3ba38c487e2fa367bb7a84a6c382.tar.gz | |
avformat/iamf_parse: prevent overreads in update_extradata
Fixes: libavcodec/put_bits.h:232:32: runtime error: shift exponent -19 is negative
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@gmail.com>
| -rw-r--r-- | libavformat/iamf_parse.c | 17 |
1 files changed, 12 insertions, 5 deletions
diff --git a/libavformat/iamf_parse.c b/libavformat/iamf_parse.c index 71497876ac..46a74ea679 100644 --- a/libavformat/iamf_parse.c +++ b/libavformat/iamf_parse.c @@ -288,7 +288,7 @@ static int update_extradata(AVCodecParameters *codecpar) uint8_t buf[6]; int size = FFMIN(codecpar->extradata_size, sizeof(buf)); - init_put_bits(&pb, buf, size); + init_put_bits(&pb, buf, sizeof(buf)); ret = init_get_bits8(&gb, codecpar->extradata, size); if (ret < 0) return ret; @@ -304,7 +304,10 @@ static int update_extradata(AVCodecParameters *codecpar) skip_bits(&gb, 4); put_bits(&pb, 4, codecpar->ch_layout.nb_channels); // set channel config - ret = put_bits_left(&pb); + ret = get_bits_left(&gb); + if (ret < 0) + return AVERROR_INVALIDDATA; + ret = FFMIN(ret, put_bits_left(&pb)); while (ret >= 32) { put_bits32(&pb, get_bits_long(&gb, 32)); ret -= 32; @@ -317,9 +320,10 @@ static int update_extradata(AVCodecParameters *codecpar) } case AV_CODEC_ID_FLAC: { uint8_t buf[13]; + int size = FFMIN(codecpar->extradata_size, sizeof(buf)); init_put_bits(&pb, buf, sizeof(buf)); - ret = init_get_bits8(&gb, codecpar->extradata, codecpar->extradata_size); + ret = init_get_bits8(&gb, codecpar->extradata, size); if (ret < 0) return ret; @@ -328,11 +332,14 @@ static int update_extradata(AVCodecParameters *codecpar) put_bits(&pb, 20, get_bits(&gb, 20)); // samplerate skip_bits(&gb, 3); put_bits(&pb, 3, codecpar->ch_layout.nb_channels - 1); - ret = put_bits_left(&pb); + ret = get_bits_left(&gb); + if (ret < 0) + return AVERROR_INVALIDDATA; + ret = FFMIN(ret, put_bits_left(&pb)); put_bits(&pb, ret, get_bits(&gb, ret)); flush_put_bits(&pb); - memcpy(codecpar->extradata, buf, sizeof(buf)); + memcpy(codecpar->extradata, buf, put_bytes_output(&pb)); break; } } |