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

[Arnd Bergmann]

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: Arnd Bergmann <arnd@xxxxxxxx>

I hope Eric can test this with the original reproducer, or maybe someone
could create a test case that can be added into LTP.

      Arnd