linux-kernel - Re: [PATCH] signal: remove the wrong signal_pending() check in restore_user

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CAK8P3a3Dv+hqnQHWU2nG5rB+hGrqbcDC3DUoNGZAzNGJgJwizA@mail.gmail.com>
Date:   Tue, 4 Jun 2019 18:37:26 +0200
From:   Arnd Bergmann <arnd@...db.de>
To:     Oleg Nesterov <oleg@...hat.com>
Cc:     Andrew Morton <akpm@...ux-foundation.org>,
        Deepa Dinamani <deepa.kernel@...il.com>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        dbueso@...e.de, Jens Axboe <axboe@...nel.dk>,
        Davidlohr Bueso <dave@...olabs.net>, e@...24.org,
        Jason Baron <jbaron@...mai.com>,
        Linux FS-devel Mailing List <linux-fsdevel@...r.kernel.org>,
        linux-aio <linux-aio@...ck.org>, omar.kilani@...il.com,
        Thomas Gleixner <tglx@...utronix.de>,
        "# 3.4.x" <stable@...r.kernel.org>,
        Al Viro <viro@...iv.linux.org.uk>,
        "Eric W. Biederman" <ebiederm@...ssion.com>,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        David Laight <David.Laight@...lab.com>
Subject: Re: [PATCH] signal: remove the wrong signal_pending() check in restore_user_sigmask()

On Tue, Jun 4, 2019 at 3:41 PM Oleg Nesterov <oleg@...hat.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@...24.org>
> Fixes: 854a6ed56839a40f6b5d02a2962f48841482eec4 ("signal: Add restore_user_sigmask()")
> cc: stable@...r.kernel.org (v5.0+)
> Signed-off-by: Oleg Nesterov <oleg@...hat.com>

Acked-by: Arnd Bergmann <arnd@...db.de>

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