linux-kernel - Re: [ 3/7] ext4: fix memory leak in xattr

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Date:	Mon, 21 Oct 2013 19:30:22 -0200
From:	Felipe Pena <felipensp@...il.com>
To:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc:	linux-kernel@...r.kernel.org, stable@...r.kernel.org,
	Dave Jones <davej@...oraproject.org>,
	Theodore Tso <tytso@....edu>, Eric Sandeen <sandeen@...hat.com>
Subject: Re: [ 3/7] ext4: fix memory leak in xattr

Hi,

On Fri, Oct 18, 2013 at 4:52 PM, Greg Kroah-Hartman
<gregkh@...uxfoundation.org> wrote:
> 3.0-stable review patch.  If anyone has any objections, please let me know.
>
> ------------------
>
> From: Dave Jones <davej@...hat.com>
>
> commit 6e4ea8e33b2057b85d75175dd89b93f5e26de3bc upstream.
>
> If we take the 2nd retry path in ext4_expand_extra_isize_ea, we
> potentionally return from the function without having freed these
> allocations.  If we don't do the return, we over-write the previous
> allocation pointers, so we leak either way.
>
> Spotted with Coverity.
>
> [ Fixed by tytso to set is and bs to NULL after freeing these
>   pointers, in case in the retry loop we later end up triggering an
>   error causing a jump to cleanup, at which point we could have a double
>   free bug. -- Ted ]
>
> Signed-off-by: Dave Jones <davej@...oraproject.org>
> Signed-off-by: "Theodore Ts'o" <tytso@....edu>
> Reviewed-by: Eric Sandeen <sandeen@...hat.com>
> Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
>
> ---
>  fs/ext4/xattr.c |    2 ++
>  1 file changed, 2 insertions(+)
>
> --- a/fs/ext4/xattr.c
> +++ b/fs/ext4/xattr.c
> @@ -1271,6 +1271,8 @@ retry:
>                                     s_min_extra_isize) {
>                                         tried_min_extra_isize++;
>                                         new_extra_isize = s_min_extra_isize;
> +                                       kfree(is); is = NULL;
> +                                       kfree(bs); bs = NULL;

Looks like such lines are not conforming to coding style, or?

>                                         goto retry;
>                                 }
>                                 error = -1;
>
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@...r.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at  http://www.tux.org/lkml/



-- 
Regards,
Felipe Pena
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/