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From: Theodore Ts'o <tytso@mit.edu>
To: Chen Gang <gang.chen@asianux.com>
Cc: jack@suse.cz, akpm@linux-foundation.org, linux-ext4@vger.kernel.org
Subject: Re: [PATCH] fs/ext3: set pointer = NULL, after kfree it
Date: Tue, 25 Dec 2012 13:51:55 -0500	[thread overview]
Message-ID: <20121225185155.GE5318@thunk.org> (raw)
In-Reply-To: <50D7EEF6.4070005@asianux.com>

On Mon, Dec 24, 2012 at 01:58:14PM +0800, Chen Gang wrote:
> 
>   set s->base = NULL, after kfree it.
> 
> Signed-off-by: Chen Gang <gang.chen@asianux.com>

Was this to fix something flagged by some static code checker?  The
only caller of ext3_xattr_block_set() is ext3_xattr_set_handle(), and
s->base is stored on the stack, and as soon as ext3_xattr_block_set()
returns, the object will disappear.  So it seems pretty hard to see
how this could lead to a use-after-free bug.

    	       	       	 		- Ted

  reply	other threads:[~2012-12-25 18:52 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-12-24  5:58 [PATCH] fs/ext3: set pointer = NULL, after kfree it Chen Gang
2012-12-25 18:51 ` Theodore Ts'o [this message]
2012-12-26  2:33   ` Chen Gang
2012-12-31 15:19     ` Jan Kara

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