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| author | John Brooks <john.brooks@bluecherry.net> | 2012-01-03 23:27:35 -0700 |
|---|---|---|
| committer | Kostya Shishkov <kostya.shishkov@gmail.com> | 2012-01-04 10:32:23 +0100 |
| commit | aacf6b3a2fd8bc8603e3deaa6e612ea03cf08707 (patch) | |
| tree | 4a0298252fe006b4b2442804a63f9dfdb9322b04 /libavcodec/rv34.c | |
| parent | 98f24ecd6cfc9c57a555aae6bfcd3d9a4ce9503d (diff) | |
| download | ffmpeg-aacf6b3a2fd8bc8603e3deaa6e612ea03cf08707.tar.gz | |
rv34: fix invalid memory access for small video dimensions
For small video dimensions calculations of the upper bound for pixel
access may result in negative value. Using an unsigned comparison
works only if the greater operand is non-negative. This is fixed by
doing edge emulation explicitly for such conditions.
Signed-off-by: Kostya Shishkov <kostya.shishkov@gmail.com>
Diffstat (limited to 'libavcodec/rv34.c')
| -rw-r--r-- | libavcodec/rv34.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/libavcodec/rv34.c b/libavcodec/rv34.c index db2e53aaa5..91d678876a 100644 --- a/libavcodec/rv34.c +++ b/libavcodec/rv34.c @@ -680,8 +680,9 @@ static inline void rv34_mc(RV34DecContext *r, const int block_type, srcY += src_y * s->linesize + src_x; srcU += uvsrc_y * s->uvlinesize + uvsrc_x; srcV += uvsrc_y * s->uvlinesize + uvsrc_x; - if( (unsigned)(src_x - !!lx*2) > s->h_edge_pos - !!lx*2 - (width <<3) - 4 - || (unsigned)(src_y - !!ly*2) > s->v_edge_pos - !!ly*2 - (height<<3) - 4){ + if(s->h_edge_pos - (width << 3) < 6 || s->v_edge_pos - (height << 3) < 6 || + (unsigned)(src_x - !!lx*2) > s->h_edge_pos - !!lx*2 - (width <<3) - 4 || + (unsigned)(src_y - !!ly*2) > s->v_edge_pos - !!ly*2 - (height<<3) - 4) { uint8_t *uvbuf = s->edge_emu_buffer + 22 * s->linesize; srcY -= 2 + 2*s->linesize; |