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From: Ted Ts'o <tytso@mit.edu>
To: Al Viro <viro@ZenIV.linux.org.uk>,
	Andrew Morton <akpm@linux-foundation.org>,
	Djalal Harouni <tixxdz@opendz.org>,
	Hugh Dickins <hughd@google.com>,
	Minchan Kim <minchan.kim@gmail.com>,
	KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
	Wu Fengguang <fengguang.wu@intel.com>,
	linux-mm@kvack.org, linux-kernel@vger.kernel.org,
	"J. Bruce Fields" <bfields@fieldses.org>,
	Neil Brown <neilb@suse.de>,
	Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>,
	Christoph Hellwig <hch@infradead.org>,
	linux-ext4@vger.kernel.org
Subject: Re: [PATCH] mm: add missing mutex lock arround notify_change
Date: Tue, 20 Dec 2011 17:45:58 -0500	[thread overview]
Message-ID: <20111220224558.GA27615@thunk.org> (raw)
In-Reply-To: <20111220220901.GA1770@thunk.org>

I just took a closer look, and we don't need to take immediate action;
there is no security issue here were someone could modify a writable
suid file as I had originally feared.  It's not as obvious as it could
be because of how the code is broken up, but in mext_check_arguments()
in fs/ext4/move_extent.c, we return with an error if the donor file
has the SUID or SGID bit set, so we'll never actually end up calling
file_remove_suid().  So in fact the right patch is just to remove the
call to file_remove_suid() altogether.

						- Ted

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  reply	other threads:[~2011-12-20 22:46 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-12-16 11:25 [PATCH] mm: add missing mutex lock arround notify_change Djalal Harouni
2011-12-16 20:55 ` Andrew Morton
2011-12-16 21:54   ` Djalal Harouni
2011-12-17 21:41   ` Al Viro
2011-12-17 22:10     ` Al Viro
2011-12-20 22:09       ` Ted Ts'o
2011-12-20 22:45         ` Ted Ts'o [this message]
2011-12-19  1:43     ` Dave Chinner
2011-12-19  2:03       ` Al Viro
2011-12-19  2:06         ` Al Viro
2011-12-19  5:07           ` Dave Chinner
2011-12-19  4:22         ` Dave Chinner

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