From: Qian Cai <cai@lca.pw>
To: Grzegorz Halat <ghalat@redhat.com>
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org,
linux-fsdevel@vger.kernel.org, linux-doc@vger.kernel.org,
ssaner@redhat.com, atomlin@redhat.com, oleksandr@redhat.com,
vbendel@redhat.com, kirill@shutemov.name,
khlebnikov@yandex-team.ru, borntraeger@de.ibm.com,
Andrew Morton <akpm@linux-foundation.org>,
Iurii Zaikin <yzaikin@google.com>,
Kees Cook <keescook@chromium.org>,
Luis Chamberlain <mcgrof@kernel.org>,
Jonathan Corbet <corbet@lwn.net>
Subject: Re: [PATCH 1/1] mm: sysctl: add panic_on_mm_error sysctl
Date: Mon, 27 Jan 2020 07:26:21 -0500 [thread overview]
Message-ID: <F352EA1C-7E7C-4C0C-8F23-EC33080EBB9E@lca.pw> (raw)
In-Reply-To: <20200127101100.92588-1-ghalat@redhat.com>
> On Jan 27, 2020, at 5:11 AM, Grzegorz Halat <ghalat@redhat.com> wrote:
>
> Memory management subsystem performs various checks at runtime,
> if an inconsistency is detected then such event is being logged and kernel
> continues to run. While debugging such problems it is helpful to collect
> memory dump as early as possible. Currently, there is no easy way to panic
> kernel when such error is detected.
>
> It was proposed[1] to panic the kernel if panic_on_oops is set but this
> approach was not accepted. One of alternative proposals was introduction of
> a new sysctl.
>
> The patch adds panic_on_mm_error sysctl. If the sysctl is set then the
> kernel will be crashed when an inconsistency is detected by memory
> management. This currently means panic when bad page or bad PTE
> is detected(this may be extended to other places in MM).
>
> Another use case of this sysctl may be in security-wise environments,
> it may be more desired to crash machine than continue to run with
> potentially damaged data structures.
Well, on the other hand, this will allow a normal user to more easily crash the system due to a recoverable bug which could result in local DoS.
next prev parent reply other threads:[~2020-01-27 12:26 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-27 10:11 [PATCH 1/1] mm: sysctl: add panic_on_mm_error sysctl Grzegorz Halat
2020-01-27 10:28 ` Oleksandr Natalenko
2020-01-27 10:30 ` Aaron Tomlin
2020-01-27 10:42 ` Tetsuo Handa
2020-01-27 10:55 ` Aaron Tomlin
2020-01-27 11:32 ` Grzegorz Halat
2020-01-27 12:26 ` Qian Cai [this message]
2020-01-27 12:51 ` Konstantin Khlebnikov
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