| Message ID | 20190618142547.952-1-michael@niedermayer.cc |
|---|---|
| State | New |
| Headers | show |
On 18.06.2019, at 16:25, Michael Niedermayer <michael@niedermayer.cc> wrote: > Fixes: addition of unsigned offset to 0x7f56fc26a9b6 overflowed to 0x7f56fc26a8be* > Fixes: clusterfuzz-testcase-minimized-mediasource_MP4_AVC1_pipeline_integration_fuzzer-4917949056679936 > > Reported-by: Matt Wolenetz <wolenetz@google.com> > Reviewed-by: Matt Wolenetz <wolenetz@google.com> > Signed-off-by: Michael Niedermayer <michael@niedermayer.cc> > --- > libavcodec/videodsp_template.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/libavcodec/videodsp_template.c b/libavcodec/videodsp_template.c > index 94c1b7188d..eae2f1d51b 100644 > --- a/libavcodec/videodsp_template.c > +++ b/libavcodec/videodsp_template.c > @@ -44,7 +44,7 @@ void FUNC(ff_emulated_edge_mc)(uint8_t *buf, const uint8_t *src, > src_y = 1 - block_h; > } > if (src_x >= w) { > - src += (w - 1 - src_x) * sizeof(pixel); > + src -= (1 + src_x - w) * sizeof(pixel); This is really non-obvious and someone might be tempted to "simplify", especially since the old way matched the code a few lines below. I'd suggest adding a comment. > src_x = w - 1; > } else if (src_x <= -block_w) { > src += (1 - block_w - src_x) * sizeof(pixel);
On Fri, Jun 21, 2019 at 09:07:38AM +0200, Reimar Döffinger wrote: > > > On 18.06.2019, at 16:25, Michael Niedermayer <michael@niedermayer.cc> wrote: > > > Fixes: addition of unsigned offset to 0x7f56fc26a9b6 overflowed to 0x7f56fc26a8be* > > Fixes: clusterfuzz-testcase-minimized-mediasource_MP4_AVC1_pipeline_integration_fuzzer-4917949056679936 > > > > Reported-by: Matt Wolenetz <wolenetz@google.com> > > Reviewed-by: Matt Wolenetz <wolenetz@google.com> > > Signed-off-by: Michael Niedermayer <michael@niedermayer.cc> > > --- > > libavcodec/videodsp_template.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/libavcodec/videodsp_template.c b/libavcodec/videodsp_template.c > > index 94c1b7188d..eae2f1d51b 100644 > > --- a/libavcodec/videodsp_template.c > > +++ b/libavcodec/videodsp_template.c > > @@ -44,7 +44,7 @@ void FUNC(ff_emulated_edge_mc)(uint8_t *buf, const uint8_t *src, > > src_y = 1 - block_h; > > } > > if (src_x >= w) { > > - src += (w - 1 - src_x) * sizeof(pixel); > > + src -= (1 + src_x - w) * sizeof(pixel); > > This is really non-obvious and someone might be tempted to "simplify", especially since the old way matched the code a few lines below. > I'd suggest adding a comment. will apply with a comment thanks [...]
diff --git a/libavcodec/videodsp_template.c b/libavcodec/videodsp_template.c index 94c1b7188d..eae2f1d51b 100644 --- a/libavcodec/videodsp_template.c +++ b/libavcodec/videodsp_template.c @@ -44,7 +44,7 @@ void FUNC(ff_emulated_edge_mc)(uint8_t *buf, const uint8_t *src, src_y = 1 - block_h; } if (src_x >= w) { - src += (w - 1 - src_x) * sizeof(pixel); + src -= (1 + src_x - w) * sizeof(pixel); src_x = w - 1; } else if (src_x <= -block_w) { src += (1 - block_w - src_x) * sizeof(pixel);