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authorAndreas Rheinhardt <andreas.rheinhardt@gmail.com>2019-09-28 04:26:01 +0200
committerMichael Niedermayer <michael@niedermayer.cc>2019-09-28 17:24:32 +0200
commitf7bc0386d935e541a610a36595476710c036bfae (patch)
tree6bf8d3bbb39dbb8e6b8f45e226399f99ee362192 /libavcodec/ffv1enc.c
parent736c7c20e7819811dc59f43490563789b192eb6e (diff)
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/ffv1enc.c')
-rw-r--r--libavcodec/ffv1enc.c17
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++) {