From: Oleg Nesterov <oleg@redhat.com>
To: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Avi Weiss <thnkslprpt@gmail.com>,
Andrew Morton <akpm@linux-foundation.org>,
Christian Brauner <brauner@kernel.org>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] signal: respect the blocked mask in dequeue_synchronous_signal()
Date: Fri, 23 Oct 2026 12:02:06 +0200 [thread overview]
Message-ID: <atswnpqj8VHJwqu9@redhat.com> (raw)
In-Reply-To: <878q3po5a1.fsf@email.froward.int.ebiederm.org>
On 10/22, Eric W. Biederman wrote:
>
> Oleg Nesterov <oleg@redhat.com> writes:
>
> > And afaics we have another problem. sys_rt_sigqueueinfo() allows to
> > send a SI_FROMKERNEL RT signal to itself.
>
> I don't see where your proposed code is addressing this.
Hmm. It doesn't even try. And yes, I know it is deliberate, I know that
CRIU uses this feature.
> > In this case sigmask(q->info.si_signo) leads to UB on 32-bit.
>
> I presume you are referring to a signal number that exceeds 32
> being put into a 32bit mask. That does seem worth fixing.
Yes. That is all. I just tried to explain why this can happen.
sys_rt_sigqueueinfo() is the reason. The kernel doesn't sent
SI_FROMKERNEL signals with si_signo >= SIGRTMIN.
OK, let me write the changelog and simplify this change...
Oleg.
next prev parent reply other threads:[~2026-10-23 10:02 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-10-22 6:10 Avi Weiss
2026-10-22 11:58 ` Oleg Nesterov
2026-10-22 20:21 ` Eric W. Biederman
2026-10-23 10:02 ` Oleg Nesterov [this message]
2026-10-23 16:28 ` Eric W. Biederman
2026-10-22 20:15 ` Eric W. Biederman
2026-10-23 10:48 ` [PATCH] signal: cleanup the .si_signo checks " Oleg Nesterov
2026-10-23 10:50 ` Oleg Nesterov
2026-10-23 16:46 ` Eric W. Biederman
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