On Tue, Jun 4, 2019 at 3:41 PM Oleg Nesterov oleg@redhat.com 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@80x24.org Fixes: 854a6ed56839a40f6b5d02a2962f48841482eec4 ("signal: Add restore_user_sigmask()") cc: stable@vger.kernel.org (v5.0+) Signed-off-by: Oleg Nesterov oleg@redhat.com
Acked-by: Deepa Dinamani deepa.kernel@gmail.com
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