On Tue, Jul 09, 2024 at 02:41:16PM +0200, epirat07@gmail.com wrote:
> 
> 
> On 6 Jul 2024, at 11:26, Stefano Sabatini wrote:
> 
> > On date Tuesday 2024-07-02 20:38:00 +0200, Marvin Scholz wrote:
> >> An incorrect calculation in ff_perlin_init causes a write to the
> >> stack array at index 256, which is out of bounds.
> >>
> >> Fixes: CID1608711
> >> ---
> >>  libavfilter/perlin.c | 2 +-
> >>  1 file changed, 1 insertion(+), 1 deletion(-)
> >>
> >> diff --git a/libavfilter/perlin.c b/libavfilter/perlin.c
> >> index 09bae7ad33..ffad8c1e4e 100644
> >> --- a/libavfilter/perlin.c
> >> +++ b/libavfilter/perlin.c
> >> @@ -129,7 +129,7 @@ int ff_perlin_init(FFPerlin *perlin, double period, int octaves, double persiste
> >>          for (i = 0; i < 256; i++) {
> >>              unsigned int random_idx = av_lfg_get(&lfg) % (256-i);
> >>              uint8_t random_val = random_permutations[random_idx];
> >> -            random_permutations[random_idx] = random_permutations[256-i];
> >> +            random_permutations[random_idx] = random_permutations[255-i];
> >>
> >>              perlin->permutations[i] = perlin->permutations[i+256] = random_val;
> >>          }
> >
> > Looks good, thanks.
> 
> Please push then, I do not have commit access.

applied

thx

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

Awnsering whenever a program halts or runs forever is
On a turing machine, in general impossible (turings halting problem).
On any real computer, always possible as a real computer has a finite number
of states N, and will either halt in less than N cycles or never halt.