ffmpeg | branch: master | Michael Niedermayer <mich...@niedermayer.cc> | Sat Nov 14 21:11:52 2015 +0100| [a105f52855d08e4ab1ed7306da8e32fc90d6d647] | committer: Michael Niedermayer
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 <mich...@niedermayer.cc> > http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=a105f52855d08e4ab1ed7306da8e32fc90d6d647 --- libavcodec/error_resilience.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/libavcodec/error_resilience.c b/libavcodec/error_resilience.c index 2c741a4..5a75fad 100644 --- a/libavcodec/error_resilience.c +++ b/libavcodec/error_resilience.c @@ -381,14 +381,19 @@ 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]; @@ -413,7 +418,7 @@ 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; @@ -442,7 +447,7 @@ 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 } }; @@ -675,7 +680,7 @@ 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; _______________________________________________ ffmpeg-cvslog mailing list ffmpeg-cvslog@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-cvslog
