linux-kernel - Re: [PATCH] exit: Detect and fix irq disabled state in oops

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] [day] [month] [year] [list]

Message-ID: <Y8qxX4iZUZYOaCD0@hirez.programming.kicks-ass.net>
Date:   Fri, 20 Jan 2023 16:21:03 +0100
From:   Peter Zijlstra <peterz@...radead.org>
To:     Nicholas Piggin <npiggin@...il.com>
Cc:     Ingo Molnar <mingo@...hat.com>, linux-kernel@...r.kernel.org,
        Michael Ellerman <mpe@...erman.id.au>,
        "Eric W. Biederman" <ebiederm@...ssion.com>
Subject: Re: [PATCH] exit: Detect and fix irq disabled state in oops

On Fri, Jan 20, 2023 at 11:18:20AM +1000, Nicholas Piggin wrote:
> If a task oopses with irqs disabled, this can cause various cascading
> problems in the oops path such as sleep-from-invalid warnings, and
> potentially worse.
> 
> Since commit 0258b5fd7c712 ("coredump: Limit coredumps to a single
> thread group"), the unconditional irq enable in coredump_task_exit()
> will "fix" the irq state to be enabled early in do_exit(), so currently
> this may not be triggerable, but that is coincidental and fragile.
> 
> Detect and fix the irqs_disabled() condition in the oops path before
> calling do_exit(), similarly to the way in_atomic() is handled.
> 
> Link: https://lore.kernel.org/lkml/20221004094401.708299-1-npiggin@gmail.com/
> Reported-by: Michael Ellerman <mpe@...erman.id.au>
> Acked-by: "Eric W. Biederman" <ebiederm@...ssion.com>
> Signed-off-by: Nicholas Piggin <npiggin@...il.com>
> ---
> Hi Peter,
> 
> Would you consider taking this through the sched tree?

Yep, can do, let me go queue it.