[FFmpeg-cvslog] eacmv: fix potential pointer arithmetic overflows

[Laurent Aimar]

ffmpeg | branch: release/0.8 | Laurent Aimar <fenrir at videolan.org> | Fri Sep 30 23:42:32 2011 +0000| [34d6f22a571e230b519223e779e14b93d7e20989] | committer: Reinhard Tartler

eacmv: fix potential pointer arithmetic overflows

Signed-off-by: Janne Grunau <janne-libav at jannau.net>
(cherry picked from commit 8df8a87e3fd5bd0c3dabc676aae8fd84992932dc)

Signed-off-by: Anton Khirnov <anton at khirnov.net>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=34d6f22a571e230b519223e779e14b93d7e20989
---

 libavcodec/eacmv.c |    8 ++++----
 1 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/libavcodec/eacmv.c b/libavcodec/eacmv.c
index c968a3d..d848208 100644
--- a/libavcodec/eacmv.c
+++ b/libavcodec/eacmv.c
@@ -52,7 +52,7 @@ static void cmv_decode_intra(CmvContext * s, const uint8_t *buf, const uint8_t *
     unsigned char *dst = s->frame.data[0];
     int i;
 
-    for (i=0; i < s->avctx->height && buf+s->avctx->width<=buf_end; i++) {
+    for (i=0; i < s->avctx->height && buf_end - buf >= s->avctx->width; i++) {
         memcpy(dst, buf, s->avctx->width);
         dst += s->frame.linesize[0];
         buf += s->avctx->width;
@@ -84,7 +84,7 @@ static void cmv_decode_inter(CmvContext * s, const uint8_t *buf, const uint8_t *
 
     i = 0;
     for(y=0; y<s->avctx->height/4; y++)
-    for(x=0; x<s->avctx->width/4 && buf+i<buf_end; x++) {
+    for(x=0; x<s->avctx->width/4 && buf_end - buf > i; x++) {
         if (buf[i]==0xFF) {
             unsigned char *dst = s->frame.data[0] + (y*4)*s->frame.linesize[0] + x*4;
             if (raw+16<buf_end && *raw==0xFF) { /* intra */
@@ -118,7 +118,7 @@ static void cmv_process_header(CmvContext *s, const uint8_t *buf, const uint8_t
 {
     int pal_start, pal_count, i;
 
-    if(buf+16>=buf_end) {
+    if(buf_end - buf < 16) {
         av_log(s->avctx, AV_LOG_WARNING, "truncated header\n");
         return;
     }
@@ -135,7 +135,7 @@ static void cmv_process_header(CmvContext *s, const uint8_t *buf, const uint8_t
     pal_count = AV_RL16(&buf[14]);
 
     buf += 16;
-    for (i=pal_start; i<pal_start+pal_count && i<AVPALETTE_COUNT && buf+2<buf_end; i++) {
+    for (i=pal_start; i<pal_start+pal_count && i<AVPALETTE_COUNT && buf_end - buf >= 3; i++) {
         s->palette[i] = AV_RB24(buf);
         buf += 3;
     }