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| author | Michael Niedermayer <michael@niedermayer.cc> | 2015-11-14 21:11:52 +0100 |
|---|---|---|
| committer | Michael Niedermayer <michael@niedermayer.cc> | 2015-11-19 03:51:39 +0100 |
| commit | cb060668f12914fcd834b86c36d3c337eff0f173 (patch) | |
| tree | 24fdfd2671832e5d473e60effdd64490784265a3 | |
| parent | 7ab1f5b0d4b621dbd78bc901d38fcad6e19c375e (diff) | |
| download | ffmpeg-cb060668f12914fcd834b86c36d3c337eff0f173.tar.gz | |
avcodec/error_resilience: avoid accessing previous or next frames tables beyond height
The height of tables can be rounded up for MBAFF but this does not imply that is also true
for the previous frames
Fixes out of array reads
Fixes: c106b36fa36db8ff8f3ed0c82be7bea2/asan_heap-oob_32699f0_6321_467b9a1d7e03d7cfd310b7e65dc53bcc.mov
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit a105f52855d08e4ab1ed7306da8e32fc90d6d647)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
| -rw-r--r-- | libavcodec/error_resilience.c | 15 |
1 files changed, 10 insertions, 5 deletions
diff --git a/libavcodec/error_resilience.c b/libavcodec/error_resilience.c index 4fa7bc4e21..73c3491703 100644 --- a/libavcodec/error_resilience.c +++ b/libavcodec/error_resilience.c @@ -378,14 +378,19 @@ static void guess_mv(ERContext *s) #define MV_UNCHANGED 1 const int mb_stride = s->mb_stride; const int mb_width = s->mb_width; - const int mb_height = s->mb_height; + int mb_height = s->mb_height; int i, depth, num_avail; int mb_x, mb_y, mot_step, mot_stride; + if (s->last_pic.f && s->last_pic.f->data[0]) + mb_height = FFMIN(mb_height, (s->last_pic.f->height+15)>>4); + if (s->next_pic.f && s->next_pic.f->data[0]) + mb_height = FFMIN(mb_height, (s->next_pic.f->height+15)>>4); + set_mv_strides(s, &mot_step, &mot_stride); num_avail = 0; - for (i = 0; i < s->mb_num; i++) { + for (i = 0; i < mb_width * mb_height; i++) { const int mb_xy = s->mb_index2xy[i]; int f = 0; int error = s->error_status_table[mb_xy]; @@ -410,7 +415,7 @@ static void guess_mv(ERContext *s) if ((!(s->avctx->error_concealment&FF_EC_GUESS_MVS)) || num_avail <= mb_width / 2) { - for (mb_y = 0; mb_y < s->mb_height; mb_y++) { + for (mb_y = 0; mb_y < mb_height; mb_y++) { for (mb_x = 0; mb_x < s->mb_width; mb_x++) { const int mb_xy = mb_x + mb_y * s->mb_stride; int mv_dir = (s->last_pic.f && s->last_pic.f->data[0]) ? MV_DIR_FORWARD : MV_DIR_BACKWARD; @@ -439,7 +444,7 @@ static void guess_mv(ERContext *s) int score_sum = 0; changed = 0; - for (mb_y = 0; mb_y < s->mb_height; mb_y++) { + for (mb_y = 0; mb_y < mb_height; mb_y++) { for (mb_x = 0; mb_x < s->mb_width; mb_x++) { const int mb_xy = mb_x + mb_y * s->mb_stride; int mv_predictor[8][2] = { { 0 } }; @@ -672,7 +677,7 @@ skip_last_mv: if (none_left) return; - for (i = 0; i < s->mb_num; i++) { + for (i = 0; i < mb_width * mb_height; i++) { int mb_xy = s->mb_index2xy[i]; if (fixed[mb_xy]) fixed[mb_xy] = MV_FROZEN; |