Re: [PATCH] signal: remove the wrong signal_pending() check in restore_user_sigmask()

From: Deepa Dinamani
Date: Tue Jun 04 2019 - 14:18:38 EST


> On Tue, Jun 4, 2019 at 3:41 PM Oleg Nesterov <oleg@xxxxxxxxxx> wrote:
> >
> > This is the minimal fix for stable, I'll send cleanups later.
> >
> > The commit 854a6ed56839a40f6b5d02a2962f48841482eec4 ("signal: Add
> > restore_user_sigmask()") introduced the visible change which breaks
> > user-space: a signal temporary unblocked by set_user_sigmask() can
> > be delivered even if the caller returns success or timeout.
> >
> > Change restore_user_sigmask() to accept the additional "interrupted"
> > argument which should be used instead of signal_pending() check, and
> > update the callers.
> >
> > Reported-by: Eric Wong <e@xxxxxxxxx>
> > Fixes: 854a6ed56839a40f6b5d02a2962f48841482eec4 ("signal: Add restore_user_sigmask()")
> > cc: stable@xxxxxxxxxxxxxxx (v5.0+)
> > Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>
>

Acked-by: Deepa Dinamani <deepa.kernel@xxxxxxxxx>

The original fix posted:
https://lore.kernel.org/patchwork/patch/1077355/ would also have been
a correct fix for this problem. But, given the cleanups that are in
the pipeline, this is a better fix.

-Deepa