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avcodec/jpegxl_parser: Check get_vlc2() 

Fixes: shift exponent -1 is negative
Fixes: 63889/clusterfuzz-testcase-minimized-ffmpeg_DEMUXER_fuzzer-6009343056936960

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This commit is contained in:
Michael Niedermayer 2023-11-08 01:48:27 +01:00
parent 0ecc1f0e48
commit 850ab8f6da
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GPG Key ID: B18E8928B3948D64
1 changed files with 8 additions and 0 deletions
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8
libavcodec/jpegxl_parser.c
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@ -708,6 +708,10 @@ static int read_vlc_prefix(GetBitContext *gb, JXLEntropyDecoder *dec, JXLSymbolD
level1_codecounts[0] = hskip;
for (int i = hskip; i < 18; i++) {
len = level1_lens[prefix_codelen_map[i]] = get_vlc2(gb, level0_table, 4, 1);
if (len < 0) {
ret = AVERROR_INVALIDDATA;
goto end;
}
level1_codecounts[len]++;
if (len) {
total_code += (32 >> len);
@ -753,6 +757,10 @@ static int read_vlc_prefix(GetBitContext *gb, JXLEntropyDecoder *dec, JXLSymbolD
total_code = 0;
for (int i = 0; i < dist->alphabet_size; i++) {
len = get_vlc2(gb, level1_vlc.table, 5, 1);
if (len < 0) {
ret = AVERROR_INVALIDDATA;
goto end;
}
if (get_bits_left(gb) < 0) {
ret = AVERROR_BUFFER_TOO_SMALL;
goto end;