vp6: Fix illegal read.
Found with Address Sanitizer
Signed-off-by: Alex Converse <alex.converse@gmail.com>
(cherry picked from commit e0966eb140b3569b3d6b5b5008961944ef229c06)
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
(cherry picked from commit 8a63deab15ef41fd439be1b46d8dcb73669ccfc1)
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
diff --git a/libavcodec/vp6.c b/libavcodec/vp6.c
index 5071903..b89ff49 100644
--- a/libavcodec/vp6.c
+++ b/libavcodec/vp6.c
@@ -427,7 +427,8 @@
model1 = model->coeff_dccv[pt];
model2 = model->coeff_dcct[pt][ctx];
- for (coeff_idx=0; coeff_idx<64; ) {
+ coeff_idx = 0;
+ for (;;) {
if ((coeff_idx>1 && ct==0) || vp56_rac_get_prob(c, model2[0])) {
/* parse a coeff */
if (vp56_rac_get_prob(c, model2[2])) {
@@ -468,8 +469,10 @@
run += vp56_rac_get_prob(c, model3[i+8]) << i;
}
}
-
- cg = vp6_coeff_groups[coeff_idx+=run];
+ coeff_idx += run;
+ if (coeff_idx >= 64)
+ break;
+ cg = vp6_coeff_groups[coeff_idx];
model1 = model2 = model->coeff_ract[pt][ct][cg];
}