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| author | Michael Niedermayer <michael@niedermayer.cc> | 2022-09-10 23:49:28 +0200 |
|---|---|---|
| committer | Michael Niedermayer <michael@niedermayer.cc> | 2022-10-09 22:15:52 +0200 |
| commit | c814c2a1ff3c3659ca21488b77e861bb3cba9a59 (patch) | |
| tree | 6430a9f123006c0d593d6fb226fac33f3402fb6d | |
| parent | 056695bf43b04b16c3c9d71cf1d136dca5f48fb4 (diff) | |
| download | ffmpeg-c814c2a1ff3c3659ca21488b77e861bb3cba9a59.tar.gz | |
avcodec/dstdec: Check for overflow in build_filter()
Fixes: signed integer overflow: 1917019860 + 265558963 cannot be represented in type 'int'
Fixes: 48798/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_DST_fuzzer-4833165046317056
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit 8008940da5aa43895fd4574114309c3324249eab)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
| -rw-r--r-- | libavcodec/dstdec.c | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/libavcodec/dstdec.c b/libavcodec/dstdec.c index d7a82f34ec..7a51f6772a 100644 --- a/libavcodec/dstdec.c +++ b/libavcodec/dstdec.c @@ -214,7 +214,7 @@ static uint8_t prob_dst_x_bit(int c) return (ff_reverse[c & 127] >> 1) + 1; } -static void build_filter(int16_t table[DST_MAX_ELEMENTS][16][256], const Table *fsets) +static int build_filter(int16_t table[DST_MAX_ELEMENTS][16][256], const Table *fsets) { int i, j, k, l; @@ -225,14 +225,17 @@ static void build_filter(int16_t table[DST_MAX_ELEMENTS][16][256], const Table * int total = av_clip(length - j * 8, 0, 8); for (k = 0; k < 256; k++) { - int v = 0; + int64_t v = 0; for (l = 0; l < total; l++) v += (((k >> l) & 1) * 2 - 1) * fsets->coeff[i][j * 8 + l]; + if ((int16_t)v != v) + return AVERROR_INVALIDDATA; table[i][j][k] = v; } } } + return 0; } static int decode_frame(AVCodecContext *avctx, void *data, @@ -328,7 +331,9 @@ static int decode_frame(AVCodecContext *avctx, void *data, return AVERROR_INVALIDDATA; ac_init(ac, gb); - build_filter(s->filter, &s->fsets); + ret = build_filter(s->filter, &s->fsets); + if (ret < 0) + return ret; memset(s->status, 0xAA, sizeof(s->status)); memset(dsd, 0, frame->nb_samples * 4 * avctx->channels); |