summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorMichael Niedermayer <[email protected]>2014-10-03 20:15:52 +0200
committerAnton Khirnov <[email protected]>2014-12-20 10:51:41 +0100
commiteac49477aa95cf727d87d2741ee8e60be59d394b (patch)
tree9279809274f90f3c51c86ecaf2e6e6bcbe45e115
parent69a930b988ff4f88ae27e4fc24ff6ed116840b5e (diff)
gifdec: refactor interleave end handling
Fixes invalid writes with very small image heights. CC: [email protected] Bug-ID: CVE-2014-8547 Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind Signed-off-by: Anton Khirnov <[email protected]> (cherry picked from commit 0b39ac6f54505a538c21fe49a626de94c518c903) Signed-off-by: Anton Khirnov <[email protected]>
-rw-r--r--libavcodec/gifdec.c15
1 files changed, 5 insertions, 10 deletions
diff --git a/libavcodec/gifdec.c b/libavcodec/gifdec.c
index cdb7f23fd4..df5ab78aba 100644
--- a/libavcodec/gifdec.c
+++ b/libavcodec/gifdec.c
@@ -125,26 +125,21 @@ static int gif_read_image(GifState *s, AVFrame *frame)
case 1:
y1 += 8;
ptr += linesize * 8;
- if (y1 >= height) {
- y1 = pass ? 2 : 4;
- ptr = ptr1 + linesize * y1;
- pass++;
- }
break;
case 2:
y1 += 4;
ptr += linesize * 4;
- if (y1 >= height) {
- y1 = 1;
- ptr = ptr1 + linesize;
- pass++;
- }
break;
case 3:
y1 += 2;
ptr += linesize * 2;
break;
}
+ while (y1 >= height) {
+ y1 = 4 >> pass;
+ ptr = ptr1 + linesize * y1;
+ pass++;
+ }
} else {
ptr += linesize;
}