From: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
To: Sergei Trofimovich <slyfox@gentoo.org>,
Andrew Morton <akpm@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org, linux-ia64@vger.kernel.org
Subject: Re: [PATCH] ia64: module: fix symbolizer crash on fdescr
Date: Sun, 4 Apr 2021 22:53:14 +0200 [thread overview]
Message-ID: <a83c7df8-5747-9f88-11f8-94834ce36199@physik.fu-berlin.de> (raw)
In-Reply-To: <20210403074803.3309096-1-slyfox@gentoo.org>
Hi Sergei!
On 4/3/21 9:48 AM, Sergei Trofimovich wrote:
> Noticed failure as a crash on ia64 when tried to symbolize all
> backtraces collected by page_owner=on:
>
> $ cat /sys/kernel/debug/page_owner
> <oops>
>
> CPU: 1 PID: 2074 Comm: cat Not tainted 5.12.0-rc4 #226
> Hardware name: hp server rx3600, BIOS 04.03 04/08/2008
> ip is at dereference_module_function_descriptor+0x41/0x100
>
> Crash happens at dereference_module_function_descriptor() due to
> use-after-free when dereferencing ".opd" section header.
>
> All section headers are already freed after module is laoded
> successfully.
>
> To keep symbolizer working the change stores ".opd" address
> and size after module is relocated to a new place and before
> section headers are discarded.
>
> To make similar errors less obscure module_finalize() now
> zeroes out all variables relevant to module loading only.
Typo: s/zeroes/zero/.
Adrian
--
.''`. John Paul Adrian Glaubitz
: :' : Debian Developer - glaubitz@debian.org
`. `' Freie Universitaet Berlin - glaubitz@physik.fu-berlin.de
`- GPG: 62FF 8A75 84E0 2956 9546 0006 7426 3B37 F5B5 F913
prev parent reply other threads:[~2021-04-04 20:53 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-03 7:48 [PATCH] ia64: module: fix symbolizer crash on fdescr Sergei Trofimovich
2021-04-04 20:53 ` John Paul Adrian Glaubitz [this message]
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