From: Theodore Ts'o <tytso@mit.edu>
To: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>,
linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] ext4: remove static from struct match_token used in token2str
Date: Sun, 23 Sep 2012 22:59:35 -0400 [thread overview]
Message-ID: <20120924025935.GA27627@thunk.org> (raw)
In-Reply-To: <1348276860-21705-1-git-send-email-herton.krzesinski@canonical.com>
On Fri, Sep 21, 2012 at 10:21:00PM -0300, Herton Ronaldo Krzesinski wrote:
> There is no reason to use static there, and it will cause issues when
> reading /proc/fs/ext4/<partition>/options concurrently.
>
> Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com>
> Cc: stable@vger.kernel.org # 3.4+
Herton,
Thanks for finding the bug fix! I changed the commit descipription
slightly and have applied your patch to the ext4 tree.
- Ted
ext4: fix crash when accessing /proc/mounts concurrently
From: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com>
The crash was caused by a variable being erronously declared static in
token2str().
In addition to /proc/mounts, the problem can also be easily replicated
by accessing /proc/fs/ext4/<partition>/options in parallel:
$ cat /proc/fs/ext4/<partition>/options > options.txt
... and then running the following command in two different terminals:
$ while diff /proc/fs/ext4/<partition>/options options.txt; do true; done
This is also the cause of the following a crash while running xfstests
#234, as reported in the following bug reports:
https://bugs.launchpad.net/bugs/1053019
https://bugzilla.kernel.org/show_bug.cgi?id=47731
Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: Brad Figg <brad.figg@canonical.com>
Cc: stable@vger.kernel.org
prev parent reply other threads:[~2012-09-24 2:59 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-22 1:21 [PATCH] ext4: remove static from struct match_token used in token2str Herton Ronaldo Krzesinski
2012-09-24 2:59 ` Theodore Ts'o [this message]
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