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

[Michael Niedermayer]

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 
> ---
>  libavcodec/h264_slice.c | 16 +---
>  1 file changed, 9 insertions(+), 7 deletions(-)

patchset applied

[...]
-- 
Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Democracy is the form of government in which you can choose your dictator


signature.asc
Description: Digital signature
___
ffmpeg-devel mailing list
ffmpeg-devel@ffmpeg.org
http://ffmpeg.org/mailman/listinfo/ffmpeg-devel

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

[Michael Niedermayer]

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 
---
 libavcodec/h264_slice.c | 16 +---
 1 file changed, 9 insertions(+), 7 deletions(-)

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;
 }
 }
 
-- 
2.13.0

___
ffmpeg-devel mailing list
ffmpeg-devel@ffmpeg.org
http://ffmpeg.org/mailman/listinfo/ffmpeg-devel