Thanks for the feedback. Yes, I confirm that I'm the original author
of this patch. Here is the adjusted version. If necessary, I can write
proof-of-concept and attach it here.

пн, 9 авг. 2021 г. в 18:32, Siddhesh Poyarekar <siddhesh@gotplt.org>:
>
> On 8/9/21 6:51 PM, Siddhesh Poyarekar wrote:
> > On 8/9/21 5:55 PM, Никита Попов via Libc-alpha wrote:
> >> Helper thread frees copied attribute on NOTIFY_REMOVED message
> >> received from the OS kernel. Unfortunately, it fails to check whether
> >> copied attribute actually exists (data.attr != NULL). This worked
> >> earlier because free() checks passed pointer before actually
> >> attempting to release corresponding memory. But __pthread_attr_destroy
> >> assumes pointer is not NULL. So passing NULL pointer to
> >> __pthread_attr_destroy will result in segmentation fault. This
> >> scenario is possible if notification->sigev_notify_attributes == NULL
> >> (which means default thread attributes should be used).
> >
> > Thank you, the fix looks good to me.  Do you have a test case to go with
> > it?
>
> Also, I don't know if you have an FSF copyright assignment, but it's no
> longer necessary.  Please confirm that you're the original author and
> are authorized to contribute this patch by adding a DCO, i.e. add a
> Signed-off-by to indicate that.  See also:
>
> https://developercertificate.org/
>
> Thanks,
> Siddhesh