From 6086731299e4d249ddc459e406b2ebb0cb71f6f4 Mon Sep 17 00:00:00 2001 From: David Conrad Date: Fri, 16 Apr 2010 12:21:44 +0000 Subject: vp3: More buffer length checks .5% slower to fix some crashes on invalid streams Originally committed as revision 22893 to svn://svn.ffmpeg.org/ffmpeg/trunk --- libavcodec/vp3.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) (limited to 'libavcodec') diff --git a/libavcodec/vp3.c b/libavcodec/vp3.c index c7c85389a7..e46e6a437a 100644 --- a/libavcodec/vp3.c +++ b/libavcodec/vp3.c @@ -379,7 +379,7 @@ static int unpack_superblocks(Vp3DecodeContext *s, GetBitContext *gb) /* unpack the list of partially-coded superblocks */ bit = get_bits1(gb); - while (current_superblock < s->superblock_count) { + while (current_superblock < s->superblock_count && get_bits_left(gb) > 0) { current_run = get_vlc2(gb, s->superblock_run_length_vlc.table, 6, 2) + 1; if (current_run == 34) @@ -409,7 +409,8 @@ static int unpack_superblocks(Vp3DecodeContext *s, GetBitContext *gb) current_superblock = 0; bit = get_bits1(gb); - while (superblocks_decoded < s->superblock_count - num_partial_superblocks) { + while (superblocks_decoded < s->superblock_count - num_partial_superblocks + && get_bits_left(gb) > 0) { current_run = get_vlc2(gb, s->superblock_run_length_vlc.table, 6, 2) + 1; if (current_run == 34) @@ -458,7 +459,7 @@ static int unpack_superblocks(Vp3DecodeContext *s, GetBitContext *gb) int sb_end = sb_start + (plane ? s->c_superblock_count : s->y_superblock_count); int num_coded_frags = 0; - for (i = sb_start; i < sb_end; i++) { + for (i = sb_start; i < sb_end && get_bits_left(gb) > 0; i++) { /* iterate through all 16 fragments in a superblock */ for (j = 0; j < 16; j++) { @@ -542,6 +543,8 @@ static int unpack_modes(Vp3DecodeContext *s, GetBitContext *gb) * coded fragments */ for (sb_y = 0; sb_y < s->y_superblock_height; sb_y++) { for (sb_x = 0; sb_x < s->y_superblock_width; sb_x++) { + if (get_bits_left(gb) <= 0) + return -1; for (j = 0; j < 4; j++) { int mb_x = 2*sb_x + (j>>1); @@ -636,6 +639,8 @@ static int unpack_vectors(Vp3DecodeContext *s, GetBitContext *gb) * coded fragments */ for (sb_y = 0; sb_y < s->y_superblock_height; sb_y++) { for (sb_x = 0; sb_x < s->y_superblock_width; sb_x++) { + if (get_bits_left(gb) <= 0) + return -1; for (j = 0; j < 4; j++) { int mb_x = 2*sb_x + (j>>1); @@ -820,7 +825,7 @@ static int unpack_block_qpis(Vp3DecodeContext *s, GetBitContext *gb) bit = get_bits1(gb); else bit ^= 1; - } while (blocks_decoded < num_blocks); + } while (blocks_decoded < num_blocks && get_bits_left(gb) > 0); num_blocks -= num_blocks_at_qpi; } -- cgit v1.2.3