From: Oleg Nesterov <oleg@redhat.com>
To: Kusaram Devineni <kusaram@devineni.in>
Cc: Kees Cook <kees@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Andy Lutomirski <luto@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Thomas Gleixner <tglx@kernel.org>, Will Drewry <wad@chromium.org>,
Max Ver <dudududumaxver@gmail.com>,
linux-kernel@vger.kernel.org
Subject: Re: [RFC PATCH] ptrace: don't report syscall-exit if the tracee was killed by seccomp
Date: Fri, 3 Apr 2026 17:48:59 +0200 [thread overview]
Message-ID: <ac_ha5aHmkZ9fRO-@redhat.com> (raw)
In-Reply-To: <ac0c77c5-4cb0-41c9-9e88-263c1a57a20d@devineni.in>
Thanks Kusaram!
I was travelling, hope to send V2 this weekend. And write a more
detailed reply.
Just one note for now:
On 04/03, Kusaram Devineni wrote:
>
> while tracing the same overall issue locally, we hit another path where the
> forced fatal SIGSYS could be taken off the normal delivery path before
> get_signal() handled it, in our case via signalfd. There,
> force_sig_seccomp(..., true) marks SIGSYS as SA_IMMUTABLE via HANDLER_EXIT,
> but signalfd could still dequeue it before normal fatal delivery.
How?
seccomp does force_sig_seccomp() sends the signal to current, current can't
return to usermode and call signalfd_dequeue(), get_signal() must dequeue
SIGSYS and notice SA_IMMUTABLE.
And since this signal is private, signalfd_dequeue() from another thread can't
dequeue it either.
No?
Oleg.
next prev parent reply other threads:[~2026-04-03 15:49 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-22 13:44 [RFC PATCH] ptrace: don't report syscall-exit if the tracee was killed by seccomp Oleg Nesterov
2026-03-22 14:47 ` Kees Cook
2026-03-22 15:14 ` Oleg Nesterov
2026-03-23 12:09 ` Oleg Nesterov
2026-04-03 15:26 ` Kusaram Devineni
2026-04-03 15:48 ` Oleg Nesterov [this message]
2026-04-03 17:16 ` Kusaram Devineni
2026-04-04 14:33 ` Oleg Nesterov
2026-04-05 15:57 ` Oleg Nesterov
2026-04-06 10:43 ` Kusaram Devineni
2026-03-22 16:36 ` Andrew Morton
2026-03-22 17:32 ` Oleg Nesterov
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