pull request (net): ipsec 2017-10-24

pull request (net): ipsec 2017-10-24

[Steffen Klassert]

1) Fix a memleak when we don't find a inner_mode
   during bundle creation. From David Miller.

2) Fix a xfrm policy dump crash. We may crash
   on error when dumping policies via netlink.
   Fix this by initializing the policy walk
   with the cb->start method. This fix is a
   serious stable candidate. From Herbert Xu.

Please pull or let me know if there are problems.

Thanks!

The following changes since commit c0576e3975084d4699b7bfef578613fb8e1144f6:

  net: call cgroup_sk_alloc() earlier in sk_clone_lock() (2017-10-10 20:24:29 -0700)

are available in the git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec.git master

for you to fetch changes up to 1137b5e2529a8f5ca8ee709288ecba3e68044df2:

  ipsec: Fix aborted xfrm policy dump crash (2017-10-23 09:35:48 +0200)

----------------------------------------------------------------
David Miller (1):
      ipsec: Fix dst leak in xfrm_bundle_create().

Herbert Xu (1):
      ipsec: Fix aborted xfrm policy dump crash

 net/xfrm/xfrm_policy.c | 16 ++++++++--------
 net/xfrm/xfrm_user.c   | 25 +++++++++++++++----------
 2 files changed, 23 insertions(+), 18 deletions(-)

[PATCH 1/2] ipsec: Fix dst leak in xfrm_bundle_create().

[Steffen Klassert]

From: David Miller <davem@davemloft.net>

If we cannot find a suitable inner_mode value, we will leak
the currently allocated 'xdst'.

The fix is to make sure it is linked into the chain before
erroring out.

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
---
 net/xfrm/xfrm_policy.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index f062539..2746b62 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -1573,6 +1573,14 @@ static struct dst_entry *xfrm_bundle_create(struct xfrm_policy *policy,
 			goto put_states;
 		}
 
+		if (!dst_prev)
+			dst0 = dst1;
+		else
+			/* Ref count is taken during xfrm_alloc_dst()
+			 * No need to do dst_clone() on dst1
+			 */
+			dst_prev->child = dst1;
+
 		if (xfrm[i]->sel.family == AF_UNSPEC) {
 			inner_mode = xfrm_ip2inner_mode(xfrm[i],
 							xfrm_af2proto(family));
@@ -1584,14 +1592,6 @@ static struct dst_entry *xfrm_bundle_create(struct xfrm_policy *policy,
 		} else
 			inner_mode = xfrm[i]->inner_mode;
 
-		if (!dst_prev)
-			dst0 = dst1;
-		else
-			/* Ref count is taken during xfrm_alloc_dst()
-			 * No need to do dst_clone() on dst1
-			 */
-			dst_prev->child = dst1;
-
 		xdst->route = dst;
 		dst_copy_metrics(dst1, dst);
 
-- 
2.7.4

[PATCH 2/2] ipsec: Fix aborted xfrm policy dump crash

[Steffen Klassert]

From: Herbert Xu <herbert@gondor.apana.org.au>

An independent security researcher, Mohamed Ghannam, has reported
this vulnerability to Beyond Security's SecuriTeam Secure Disclosure
program.

The xfrm_dump_policy_done function expects xfrm_dump_policy to
have been called at least once or it will crash.  This can be
triggered if a dump fails because the target socket's receive
buffer is full.

This patch fixes it by using the cb->start mechanism to ensure that
the initialisation is always done regardless of the buffer situation.

Fixes: 12a169e7d8f4 ("ipsec: Put dumpers on the dump list")
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
---
 net/xfrm/xfrm_user.c | 25 +++++++++++++++----------
 1 file changed, 15 insertions(+), 10 deletions(-)

diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index b997f13..e44a0fe 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -1693,32 +1693,34 @@ static int dump_one_policy(struct xfrm_policy *xp, int dir, int count, void *ptr
 
 static int xfrm_dump_policy_done(struct netlink_callback *cb)
 {
-	struct xfrm_policy_walk *walk = (struct xfrm_policy_walk *) &cb->args[1];
+	struct xfrm_policy_walk *walk = (struct xfrm_policy_walk *)cb->args;
 	struct net *net = sock_net(cb->skb->sk);
 
 	xfrm_policy_walk_done(walk, net);
 	return 0;
 }
 
+static int xfrm_dump_policy_start(struct netlink_callback *cb)
+{
+	struct xfrm_policy_walk *walk = (struct xfrm_policy_walk *)cb->args;
+
+	BUILD_BUG_ON(sizeof(*walk) > sizeof(cb->args));
+
+	xfrm_policy_walk_init(walk, XFRM_POLICY_TYPE_ANY);
+	return 0;
+}
+
 static int xfrm_dump_policy(struct sk_buff *skb, struct netlink_callback *cb)
 {
 	struct net *net = sock_net(skb->sk);
-	struct xfrm_policy_walk *walk = (struct xfrm_policy_walk *) &cb->args[1];
+	struct xfrm_policy_walk *walk = (struct xfrm_policy_walk *)cb->args;
 	struct xfrm_dump_info info;
 
-	BUILD_BUG_ON(sizeof(struct xfrm_policy_walk) >
-		     sizeof(cb->args) - sizeof(cb->args[0]));
-
 	info.in_skb = cb->skb;
 	info.out_skb = skb;
 	info.nlmsg_seq = cb->nlh->nlmsg_seq;
 	info.nlmsg_flags = NLM_F_MULTI;
 
-	if (!cb->args[0]) {
-		cb->args[0] = 1;
-		xfrm_policy_walk_init(walk, XFRM_POLICY_TYPE_ANY);
-	}
-
 	(void) xfrm_policy_walk(net, walk, dump_one_policy, &info);
 
 	return skb->len;
@@ -2474,6 +2476,7 @@ static const struct nla_policy xfrma_spd_policy[XFRMA_SPD_MAX+1] = {
 
 static const struct xfrm_link {
 	int (*doit)(struct sk_buff *, struct nlmsghdr *, struct nlattr **);
+	int (*start)(struct netlink_callback *);
 	int (*dump)(struct sk_buff *, struct netlink_callback *);
 	int (*done)(struct netlink_callback *);
 	const struct nla_policy *nla_pol;
@@ -2487,6 +2490,7 @@ static const struct xfrm_link {
 	[XFRM_MSG_NEWPOLICY   - XFRM_MSG_BASE] = { .doit = xfrm_add_policy    },
 	[XFRM_MSG_DELPOLICY   - XFRM_MSG_BASE] = { .doit = xfrm_get_policy    },
 	[XFRM_MSG_GETPOLICY   - XFRM_MSG_BASE] = { .doit = xfrm_get_policy,
+						   .start = xfrm_dump_policy_start,
 						   .dump = xfrm_dump_policy,
 						   .done = xfrm_dump_policy_done },
 	[XFRM_MSG_ALLOCSPI    - XFRM_MSG_BASE] = { .doit = xfrm_alloc_userspi },
@@ -2539,6 +2543,7 @@ static int xfrm_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
 
 		{
 			struct netlink_dump_control c = {
+				.start = link->start,
 				.dump = link->dump,
 				.done = link->done,
 			};
-- 
2.7.4

Re: pull request (net): ipsec 2017-10-24

[David Miller]

From: Steffen Klassert <steffen.klassert@secunet.com>
Date: Tue, 24 Oct 2017 12:37:38 +0200

> 1) Fix a memleak when we don't find a inner_mode
>    during bundle creation. From David Miller.
> 
> 2) Fix a xfrm policy dump crash. We may crash
>    on error when dumping policies via netlink.
>    Fix this by initializing the policy walk
>    with the cb->start method. This fix is a
>    serious stable candidate. From Herbert Xu.
> 
> Please pull or let me know if there are problems.

Pulled, please submit #2 to -stable indeed!

Re: pull request (net): ipsec 2017-10-24

[Steffen Klassert]

On Tue, Oct 24, 2017 at 08:18:32PM +0900, David Miller wrote:
> From: Steffen Klassert <steffen.klassert@secunet.com>
> Date: Tue, 24 Oct 2017 12:37:38 +0200
> 
> > 1) Fix a memleak when we don't find a inner_mode
> >    during bundle creation. From David Miller.
> > 
> > 2) Fix a xfrm policy dump crash. We may crash
> >    on error when dumping policies via netlink.
> >    Fix this by initializing the policy walk
> >    with the cb->start method. This fix is a
> >    serious stable candidate. From Herbert Xu.
> > 
> > Please pull or let me know if there are problems.
> 
> Pulled, please submit #2 to -stable indeed!

I can do so, but whenever I sent something networking related
to -stable, it was ignored. I think this is because Greg expects
that you do the stable submissions for networking.

Re: pull request (net): ipsec 2017-10-24

[David Miller]

From: Steffen Klassert <steffen.klassert@secunet.com>
Date: Tue, 24 Oct 2017 13:35:25 +0200

> On Tue, Oct 24, 2017 at 08:18:32PM +0900, David Miller wrote:
>> From: Steffen Klassert <steffen.klassert@secunet.com>
>> Date: Tue, 24 Oct 2017 12:37:38 +0200
>> 
>> > 1) Fix a memleak when we don't find a inner_mode
>> >    during bundle creation. From David Miller.
>> > 
>> > 2) Fix a xfrm policy dump crash. We may crash
>> >    on error when dumping policies via netlink.
>> >    Fix this by initializing the policy walk
>> >    with the cb->start method. This fix is a
>> >    serious stable candidate. From Herbert Xu.
>> > 
>> > Please pull or let me know if there are problems.
>> 
>> Pulled, please submit #2 to -stable indeed!
> 
> I can do so, but whenever I sent something networking related
> to -stable, it was ignored. I think this is because Greg expects
> that you do the stable submissions for networking.

Send it, CC: me, and I'll reply making sure Greg knows.

Thanks.