xfrm: fix null pointer dereference on state and tmpl sort

Creating sub policy that matches the same outer flow as main policy does
leads to a null pointer dereference if the outer mode's family is ipv4.
For userspace compatibility, this patch just eliminates the crash i.e.,
does not introduce any new sorting rule, which would fruitlessly affect
all but the aforementioned case.

Signed-off-by: Koichiro Den <den@klaipeden.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
This commit is contained in:
Koichiro Den 2017-08-01 23:21:46 +09:00 committed by Steffen Klassert
parent e619492323
commit 3f5a95ad6c

View file

@ -1620,6 +1620,7 @@ int
xfrm_tmpl_sort(struct xfrm_tmpl **dst, struct xfrm_tmpl **src, int n,
unsigned short family, struct net *net)
{
int i;
int err = 0;
struct xfrm_state_afinfo *afinfo = xfrm_state_get_afinfo(family);
if (!afinfo)
@ -1628,6 +1629,9 @@ xfrm_tmpl_sort(struct xfrm_tmpl **dst, struct xfrm_tmpl **src, int n,
spin_lock_bh(&net->xfrm.xfrm_state_lock); /*FIXME*/
if (afinfo->tmpl_sort)
err = afinfo->tmpl_sort(dst, src, n);
else
for (i = 0; i < n; i++)
dst[i] = src[i];
spin_unlock_bh(&net->xfrm.xfrm_state_lock);
rcu_read_unlock();
return err;
@ -1638,6 +1642,7 @@ int
xfrm_state_sort(struct xfrm_state **dst, struct xfrm_state **src, int n,
unsigned short family)
{
int i;
int err = 0;
struct xfrm_state_afinfo *afinfo = xfrm_state_get_afinfo(family);
struct net *net = xs_net(*src);
@ -1648,6 +1653,9 @@ xfrm_state_sort(struct xfrm_state **dst, struct xfrm_state **src, int n,
spin_lock_bh(&net->xfrm.xfrm_state_lock);
if (afinfo->state_sort)
err = afinfo->state_sort(dst, src, n);
else
for (i = 0; i < n; i++)
dst[i] = src[i];
spin_unlock_bh(&net->xfrm.xfrm_state_lock);
rcu_read_unlock();
return err;