From: tytso@mit.edu
To: Julia Lawall <julia@diku.dk>
Cc: Andreas Dilger <adilger@sun.com>,
linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org,
kernel-janitors@vger.kernel.org
Subject: Re: [PATCH 2/2] fs/ext4: Eliminate double free
Date: Wed, 23 Dec 2009 12:53:34 +0000 [thread overview]
Message-ID: <20091223125334.GE21594@thunk.org> (raw)
In-Reply-To: <Pine.LNX.4.64.0912201806530.26912@ask.diku.dk>
On Sun, Dec 20, 2009 at 06:07:10PM +0100, Julia Lawall wrote:
> From: Julia Lawall <julia@diku.dk>
>
> b_entry_name and buffer are initially NULL, are initialized within a loop
> to the result of calling kmalloc, and are freed at the bottom of this loop.
> The loop contains gotos to cleanup, which also frees b_entry_name and
> buffer. Some of these gotos are before the reinitializations of
> b_entry_name and buffer. To maintain the invariant that b_entry_name and
> buffer are NULL at the top of the loop, and thus acceptable arguments to
> kfree, these variables are now set to NULL after the kfrees.
>
> This seems to be the simplest solution. A more complicated solution
> would be to introduce more labels in the error handling code at the end of
> the function.
Thanks, added to the ext4 patch queue.
- Ted
WARNING: multiple messages have this Message-ID (diff)
From: tytso@mit.edu
To: Julia Lawall <julia@diku.dk>
Cc: Andreas Dilger <adilger@sun.com>,
linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org,
kernel-janitors@vger.kernel.org
Subject: Re: [PATCH 2/2] fs/ext4: Eliminate double free
Date: Wed, 23 Dec 2009 07:53:34 -0500 [thread overview]
Message-ID: <20091223125334.GE21594@thunk.org> (raw)
In-Reply-To: <Pine.LNX.4.64.0912201806530.26912@ask.diku.dk>
On Sun, Dec 20, 2009 at 06:07:10PM +0100, Julia Lawall wrote:
> From: Julia Lawall <julia@diku.dk>
>
> b_entry_name and buffer are initially NULL, are initialized within a loop
> to the result of calling kmalloc, and are freed at the bottom of this loop.
> The loop contains gotos to cleanup, which also frees b_entry_name and
> buffer. Some of these gotos are before the reinitializations of
> b_entry_name and buffer. To maintain the invariant that b_entry_name and
> buffer are NULL at the top of the loop, and thus acceptable arguments to
> kfree, these variables are now set to NULL after the kfrees.
>
> This seems to be the simplest solution. A more complicated solution
> would be to introduce more labels in the error handling code at the end of
> the function.
Thanks, added to the ext4 patch queue.
- Ted
next prev parent reply other threads:[~2009-12-23 12:53 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-12-20 17:07 [PATCH 2/2] fs/ext4: Eliminate double free Julia Lawall
2009-12-20 17:07 ` Julia Lawall
2009-12-23 12:53 ` tytso [this message]
2009-12-23 12:53 ` tytso
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