ACK: [hardy, lucid/fsl-imx51, maverick/ti-omap4, natty/ti-omap4 CVE 1/1] Fix for buffer overflow in ldm_frag_add not sufficient

[Stefan Bader]

On 03.02.2012 11:34, Andy Whitcroft wrote:
> From: Timo Warns <Warns at pre-sense.de>
> 
> As Ben Hutchings discovered [1], the patch for CVE-2011-1017 (buffer
> overflow in ldm_frag_add) is not sufficient.  The original patch in
> commit c340b1d64000 ("fs/partitions/ldm.c: fix oops caused by corrupted
> partition table") does not consider that, for subsequent fragments,
> previously allocated memory is used.
> 
> [1] http://lkml.org/lkml/2011/5/6/407
> 
> Reported-by: Ben Hutchings <ben at decadent.org.uk>
> Signed-off-by: Timo Warns <warns at pre-sense.de>
> Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>
> 
> (cherry picked from commit cae13fe4cc3f24820ffb990c09110626837e85d4)
> CVE-2011-2182
> BugLink: http://bugs.launchpad.net/bugs/922371
> Signed-off-by: Andy Whitcroft <apw at canonical.com>
> ---
>  fs/partitions/ldm.c |    5 +++++
>  1 files changed, 5 insertions(+), 0 deletions(-)
> 
> diff --git a/fs/partitions/ldm.c b/fs/partitions/ldm.c
> index f7b6e88..e7a38f3 100644
> --- a/fs/partitions/ldm.c
> +++ b/fs/partitions/ldm.c
> @@ -1334,6 +1334,11 @@ static bool ldm_frag_add (const u8 *data, int size, struct list_head *frags)
>  
>  	list_add_tail (&f->list, frags);
>  found:
> +	if (rec >= f->num) {
> +		ldm_error("REC value (%d) exceeds NUM value (%d)", rec, f->num);
> +		return false;
> +	}
> +
>  	if (f->map & (1 << rec)) {
>  		ldm_error ("Duplicate VBLK, part %d.", rec);
>  		f->map &= 0x7F;			/* Mark the group as broken */

Looks ok.

Acked-by: Stefan Bader <stefan.bader at canonical.com>