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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>
This commit is contained in:
Andreas Rheinhardt 2019-09-28 04:26:01 +02:00 committed by Michael Niedermayer
parent 736c7c20e7
commit f7bc0386d9
1 changed files with 13 additions and 4 deletions
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17
libavcodec/ffv1enc.c
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@ -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++) {