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avformat/westwood_vqa: Check chunk size

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the type is also changed to int as it is interpreted as int in av_get_packet()

Fixes: signed integer overflow: 2147483647 + 1 cannot be represented in type 'int'
Fixes: 50993/clusterfuzz-testcase-minimized-ffmpeg_dem_WSVQA_fuzzer-6593408795279360
Fixes: 51896/clusterfuzz-testcase-minimized-ffmpeg_dem_WSVQA_fuzzer-4613908817903616

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Reviewed-by: Anton Khirnov <anton@khirnov.net>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This commit is contained in:
Michael Niedermayer 2022-09-22 20:08:52 +02:00
parent a9137110ed
commit 5c0df3da0b
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GPG Key ID: B18E8928B3948D64
1 changed files with 6 additions and 4 deletions
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libavformat/westwood_vqa.c
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@ -178,13 +178,15 @@ static int wsvqa_read_packet(AVFormatContext *s,
int ret = -1;
uint8_t preamble[VQA_PREAMBLE_SIZE];
uint32_t chunk_type;
uint32_t chunk_size;
int skip_byte;
int chunk_size;
unsigned skip_byte;
while (avio_read(pb, preamble, VQA_PREAMBLE_SIZE) == VQA_PREAMBLE_SIZE) {
chunk_type = AV_RB32(&preamble[0]);
chunk_size = AV_RB32(&preamble[4]);
if (chunk_size < 0)
return AVERROR_INVALIDDATA;
skip_byte = chunk_size & 0x01;
if (chunk_type == VQFL_TAG) {
@ -193,9 +195,9 @@ static int wsvqa_read_packet(AVFormatContext *s,
* so it can be combined with the next VQFR packet. This way each packet
* includes a whole frame as expected. */
wsvqa->vqfl_chunk_pos = avio_tell(pb);
wsvqa->vqfl_chunk_size = (int)(chunk_size);
if (wsvqa->vqfl_chunk_size < 0 || wsvqa->vqfl_chunk_size > 3 * (1 << 20))
if (chunk_size > 3 * (1 << 20))
return AVERROR_INVALIDDATA;
wsvqa->vqfl_chunk_size = chunk_size;
/* We need a big seekback buffer because there can be SNxx, VIEW and ZBUF
* chunks (<512 KiB total) in the stream before we read VQFR (<256 KiB) and
* seek back here. */