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[FFmpeg-devel,3/3] avcodec/cdgraphics: limit scrolling to the line

Message ID 20220609213741.18029-3-michael@niedermayer.cc
State Accepted
Commit b7e30a13d4e4557b87f977b76a6bb5e3cbe5ac78
Headers show
Series [FFmpeg-devel,1/3] avcodec/jpeglsdec: fix end check for xfrm | expand

Checks

Context Check Description
andriy/make_x86 success Make finished
andriy/make_fate_x86 success Make fate finished

Commit Message

Michael Niedermayer June 9, 2022, 9:37 p.m. UTC 
Fixes: out of array access
Fixes: 47877/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_CDGRAPHICS_fuzzer-5690504626438144

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
---
 libavcodec/cdgraphics.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Michael Niedermayer June 22, 2022, 12:05 a.m. UTC | #1 
On Thu, Jun 09, 2022 at 11:37:41PM +0200, Michael Niedermayer wrote:
> Fixes: out of array access
> Fixes: 47877/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_CDGRAPHICS_fuzzer-5690504626438144
> 
> Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
> Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
> ---
>  libavcodec/cdgraphics.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

will apply

[...]
diff mbox series

Patch

diff --git a/libavcodec/cdgraphics.c b/libavcodec/cdgraphics.c
index b851ec430b..73654019e6 100644
--- a/libavcodec/cdgraphics.c
+++ b/libavcodec/cdgraphics.c
@@ -240,7 +240,7 @@  static void cdg_scroll(CDGraphicsContext *cc, uint8_t *data,
     for (y = FFMAX(0, vinc); y < FFMIN(CDG_FULL_HEIGHT + vinc, CDG_FULL_HEIGHT); y++)
         memcpy(out + FFMAX(0, hinc) + stride * y,
                in + FFMAX(0, hinc) - hinc + (y - vinc) * stride,
-               FFMIN(stride + hinc, stride));
+               FFABS(stride) - FFABS(hinc));
 
     if (vinc > 0)
         cdg_fill_wrapper(0, 0, out,