Re: [PATCH] xfrm_user: return error pointer instead of NULL

On Thu, Sep 13, 2012 at 11:41:26PM +0200, Mathias Krause wrote:

When dump_one_state() returns an error, e.g. because of a too small
buffer to dump the whole xfrm state, xfrm_state_netlink() returns NULL
instead of an error pointer. But its callers expect an error pointer
and therefore continue to operate on a NULL skbuff.

This could lead to a privilege escalation (execution of user code in
kernel context) if the attacker has CAP_NET_ADMIN and is able to map
address 0.

Or it simply crashes with a NULL pointer dereference.

Cc: stable@vger.kernel.org
Signed-off-by: Mathias Krause <redacted>

Acked-by: Steffen Klassert <steffen.klassert@secunet.com>