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| author | Andreas Rheinhardt <andreas.rheinhardt@gmail.com> | 2019-09-28 04:26:01 +0200 |
|---|---|---|
| committer | Michael Niedermayer <michael@niedermayer.cc> | 2019-09-28 17:24:32 +0200 |
| commit | f7bc0386d935e541a610a36595476710c036bfae (patch) | |
| tree | 6bf8d3bbb39dbb8e6b8f45e226399f99ee362192 /libavcodec | |
| parent | 736c7c20e7819811dc59f43490563789b192eb6e (diff) | |
| download | ffmpeg-f7bc0386d935e541a610a36595476710c036bfae.tar.gz | |
avcodec/ffv1enc: Fix out-of-bounds-array access
libavcodec/ffv1enc.c accessed an array of uint8_t [32] via array[0][j]
in order to loop over all the uint8_t in this array of arrays. Of course
this implied an out-of-bounds access for array[0] and UBSan complained
about this. So replace this with nested loops; furthermore, factor this
out into a function of its own to easily break out of the nested loops.
This affected the FATE-tests vsynth1-ffv1, vsynth1-ffv1-v3-yuv420p,
vsynth1-ffv1-v3-yuv422p10, vsynth1-ffv1-v3-yuv444p16,
vsynth1-ffv1-v3-bgr0, vsynth1-ffv1-ffv1-v3-rgb48 as well as the
corresponding vsynth2-*, vsynth3-* and the vsynth_lena-* tests.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
Diffstat (limited to 'libavcodec')
| -rw-r--r-- | libavcodec/ffv1enc.c | 17 |
1 files changed, 13 insertions, 4 deletions
diff --git a/libavcodec/ffv1enc.c b/libavcodec/ffv1enc.c index 796d81f7c6..c521b7d445 100644 --- a/libavcodec/ffv1enc.c +++ b/libavcodec/ffv1enc.c @@ -334,6 +334,18 @@ static void write_quant_tables(RangeCoder *c, write_quant_table(c, quant_table[i]); } +static int contains_non_128(uint8_t (*initial_state)[CONTEXT_SIZE], + int nb_contexts) +{ + if (!initial_state) + return 0; + for (int i = 0; i < nb_contexts; i++) + for (int j = 0; j < CONTEXT_SIZE; j++) + if (initial_state[i][j] != 128) + return 1; + return 0; +} + static void write_header(FFV1Context *f) { uint8_t state[CONTEXT_SIZE]; @@ -428,10 +440,7 @@ static int write_extradata(FFV1Context *f) write_quant_tables(c, f->quant_tables[i]); for (i = 0; i < f->quant_table_count; i++) { - for (j = 0; j < f->context_count[i] * CONTEXT_SIZE; j++) - if (f->initial_states[i] && f->initial_states[i][0][j] != 128) - break; - if (j < f->context_count[i] * CONTEXT_SIZE) { + if (contains_non_128(f->initial_states[i], f->context_count[i])) { put_rac(c, state, 1); for (j = 0; j < f->context_count[i]; j++) for (k = 0; k < CONTEXT_SIZE; k++) { |