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[FFmpeg-devel,1/2] avcodec/h264_slice: Fix overflow in slice offset

Message ID 20170804020525.870-1-michael@niedermayer.cc
State Accepted
Commit 1f53bde6d817ae13a47748f321adbdfa79e15982
Headers show

Commit Message

Michael Niedermayer Aug. 4, 2017, 2:05 a.m. UTC 
Fixes: runtime error: signed integer overflow: 1610612736 * 2 cannot be represented in type 'int'
Fixes: 2817/clusterfuzz-testcase-minimized-5289691240726528

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
---
 libavcodec/h264_slice.c | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

Comments

Michael Niedermayer Aug. 5, 2017, 10:02 p.m. UTC | #1 
On Fri, Aug 04, 2017 at 04:05:24AM +0200, Michael Niedermayer wrote:
> Fixes: runtime error: signed integer overflow: 1610612736 * 2 cannot be represented in type 'int'
> Fixes: 2817/clusterfuzz-testcase-minimized-5289691240726528
> 
> Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
> Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
> ---
>  libavcodec/h264_slice.c | 16 +++++++++-------
>  1 file changed, 9 insertions(+), 7 deletions(-)

patchset applied

[...]
diff mbox

Patch

diff --git a/libavcodec/h264_slice.c b/libavcodec/h264_slice.c
index 2fb89b189d..4e7eba4adb 100644
--- a/libavcodec/h264_slice.c
+++ b/libavcodec/h264_slice.c
@@ -1854,17 +1854,19 @@  static int h264_slice_header_parse(const H264Context *h, H264SliceContext *sl,
             sl->deblocking_filter ^= 1;  // 1<->0
 
         if (sl->deblocking_filter) {
-            sl->slice_alpha_c0_offset = get_se_golomb(&sl->gb) * 2;
-            sl->slice_beta_offset     = get_se_golomb(&sl->gb) * 2;
-            if (sl->slice_alpha_c0_offset >  12 ||
-                sl->slice_alpha_c0_offset < -12 ||
-                sl->slice_beta_offset >  12     ||
-                sl->slice_beta_offset < -12) {
+            int slice_alpha_c0_offset_div2 = get_se_golomb(&sl->gb);
+            int slice_beta_offset_div2     = get_se_golomb(&sl->gb);
+            if (slice_alpha_c0_offset_div2 >  6 ||
+                slice_alpha_c0_offset_div2 < -6 ||
+                slice_beta_offset_div2 >  6     ||
+                slice_beta_offset_div2 < -6) {
                 av_log(h->avctx, AV_LOG_ERROR,
                        "deblocking filter parameters %d %d out of range\n",
-                       sl->slice_alpha_c0_offset, sl->slice_beta_offset);
+                       slice_alpha_c0_offset_div2, slice_beta_offset_div2);
                 return AVERROR_INVALIDDATA;
             }
+            sl->slice_alpha_c0_offset = slice_alpha_c0_offset_div2 * 2;
+            sl->slice_beta_offset     = slice_beta_offset_div2 * 2;
         }
     }