pull request (net): ipsec 2019-02-21

pull request (net): ipsec 2019-02-21

[Steffen Klassert]

1) Don't do TX bytes accounting for the esp trailer when sending
   from a request socket as this will result in an out of bounds
   memory write. From Martin Willi.

2) Destroy xfrm_state synchronously on net exit path to
   avoid nested gc flush callbacks that may trigger a
   warning in xfrm6_tunnel_net_exit(). From Cong Wang.

3) Do an unconditionally clone in pfkey_broadcast_one()
   to avoid a race when freeing the skb.
   From Sean Tranchetti.

4) Fix inbound traffic via XFRM interfaces across network
   namespaces. We did the lookup for interfaces and policies
   in the wrong namespace. From Tobias Brunner.

Please pull or let me know if there are problems.

Thanks!

The following changes since commit 6fb6e6371f8c463020a41cc0ed1915e140219c3d:

  net: dsa: mv88e6xxx: Fix serdes irq setup going recursive (2019-01-27 23:19:19 -0800)

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 660899ddf06ae8bb5bbbd0a19418b739375430c5:

  xfrm: Fix inbound traffic via XFRM interfaces across network namespaces (2019-02-18 10:58:54 +0100)

----------------------------------------------------------------
Cong Wang (1):
      xfrm: destroy xfrm_state synchronously on net exit path

Martin Willi (1):
      esp: Skip TX bytes accounting when sending from a request socket

Sean Tranchetti (1):
      af_key: unconditionally clone on broadcast

Tobias Brunner (1):
      xfrm: Fix inbound traffic via XFRM interfaces across network namespaces

 include/net/xfrm.h        | 12 +++++++++---
 net/ipv4/esp4.c           |  2 +-
 net/ipv6/esp6.c           |  2 +-
 net/ipv6/xfrm6_tunnel.c   |  2 +-
 net/key/af_key.c          | 42 ++++++++++++++++--------------------------
 net/xfrm/xfrm_interface.c |  4 ++--
 net/xfrm/xfrm_policy.c    |  4 +++-
 net/xfrm/xfrm_state.c     | 30 +++++++++++++++++++-----------
 net/xfrm/xfrm_user.c      |  2 +-
 9 files changed, 53 insertions(+), 47 deletions(-)

[PATCH 1/4] esp: Skip TX bytes accounting when sending from a request socket

[Steffen Klassert]

From: Martin Willi <martin@strongswan.org>

On ESP output, sk_wmem_alloc is incremented for the added padding if a
socket is associated to the skb. When replying with TCP SYNACKs over
IPsec, the associated sk is a casted request socket, only. Increasing
sk_wmem_alloc on a request socket results in a write at an arbitrary
struct offset. In the best case, this produces the following WARNING:

WARNING: CPU: 1 PID: 0 at lib/refcount.c:102 esp_output_head+0x2e4/0x308 [esp4]
refcount_t: addition on 0; use-after-free.
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.0.0-rc3 #2
Hardware name: Marvell Armada 380/385 (Device Tree)
[...]
[<bf0ff354>] (esp_output_head [esp4]) from [<bf1006a4>] (esp_output+0xb8/0x180 [esp4])
[<bf1006a4>] (esp_output [esp4]) from [<c05dee64>] (xfrm_output_resume+0x558/0x664)
[<c05dee64>] (xfrm_output_resume) from [<c05d07b0>] (xfrm4_output+0x44/0xc4)
[<c05d07b0>] (xfrm4_output) from [<c05956bc>] (tcp_v4_send_synack+0xa8/0xe8)
[<c05956bc>] (tcp_v4_send_synack) from [<c0586ad8>] (tcp_conn_request+0x7f4/0x948)
[<c0586ad8>] (tcp_conn_request) from [<c058c404>] (tcp_rcv_state_process+0x2a0/0xe64)
[<c058c404>] (tcp_rcv_state_process) from [<c05958ac>] (tcp_v4_do_rcv+0xf0/0x1f4)
[<c05958ac>] (tcp_v4_do_rcv) from [<c0598a4c>] (tcp_v4_rcv+0xdb8/0xe20)
[<c0598a4c>] (tcp_v4_rcv) from [<c056eb74>] (ip_protocol_deliver_rcu+0x2c/0x2dc)
[<c056eb74>] (ip_protocol_deliver_rcu) from [<c056ee6c>] (ip_local_deliver_finish+0x48/0x54)
[<c056ee6c>] (ip_local_deliver_finish) from [<c056eecc>] (ip_local_deliver+0x54/0xec)
[<c056eecc>] (ip_local_deliver) from [<c056efac>] (ip_rcv+0x48/0xb8)
[<c056efac>] (ip_rcv) from [<c0519c2c>] (__netif_receive_skb_one_core+0x50/0x6c)
[...]

The issue triggers only when not using TCP syncookies, as for syncookies
no socket is associated.

Fixes: cac2661c53f3 ("esp4: Avoid skb_cow_data whenever possible")
Fixes: 03e2a30f6a27 ("esp6: Avoid skb_cow_data whenever possible")
Signed-off-by: Martin Willi <martin@strongswan.org>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
---
 net/ipv4/esp4.c | 2 +-
 net/ipv6/esp6.c | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/ipv4/esp4.c b/net/ipv4/esp4.c
index 5459f41fc26f..10e809b296ec 100644
--- a/net/ipv4/esp4.c
+++ b/net/ipv4/esp4.c
@@ -328,7 +328,7 @@ int esp_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *
 			skb->len += tailen;
 			skb->data_len += tailen;
 			skb->truesize += tailen;
-			if (sk)
+			if (sk && sk_fullsock(sk))
 				refcount_add(tailen, &sk->sk_wmem_alloc);
 
 			goto out;
diff --git a/net/ipv6/esp6.c b/net/ipv6/esp6.c
index 5afe9f83374d..239d4a65ad6e 100644
--- a/net/ipv6/esp6.c
+++ b/net/ipv6/esp6.c
@@ -296,7 +296,7 @@ int esp6_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info
 			skb->len += tailen;
 			skb->data_len += tailen;
 			skb->truesize += tailen;
-			if (sk)
+			if (sk && sk_fullsock(sk))
 				refcount_add(tailen, &sk->sk_wmem_alloc);
 
 			goto out;
-- 
2.17.1

[PATCH 2/4] xfrm: destroy xfrm_state synchronously on net exit path

[Steffen Klassert]

From: Cong Wang <xiyou.wangcong@gmail.com>

xfrm_state_put() moves struct xfrm_state to the GC list
and schedules the GC work to clean it up. On net exit call
path, xfrm_state_flush() is called to clean up and
xfrm_flush_gc() is called to wait for the GC work to complete
before exit.

However, this doesn't work because one of the ->destructor(),
ipcomp_destroy(), schedules the same GC work again inside
the GC work. It is hard to wait for such a nested async
callback. This is also why syzbot still reports the following
warning:

 WARNING: CPU: 1 PID: 33 at net/ipv6/xfrm6_tunnel.c:351 xfrm6_tunnel_net_exit+0x2cb/0x500 net/ipv6/xfrm6_tunnel.c:351
 ...
  ops_exit_list.isra.0+0xb0/0x160 net/core/net_namespace.c:153
  cleanup_net+0x51d/0xb10 net/core/net_namespace.c:551
  process_one_work+0xd0c/0x1ce0 kernel/workqueue.c:2153
  worker_thread+0x143/0x14a0 kernel/workqueue.c:2296
  kthread+0x357/0x430 kernel/kthread.c:246
  ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352

In fact, it is perfectly fine to bypass GC and destroy xfrm_state
synchronously on net exit call path, because it is in process context
and doesn't need a work struct to do any blocking work.

This patch introduces xfrm_state_put_sync() which simply bypasses
GC, and lets its callers to decide whether to use this synchronous
version. On net exit path, xfrm_state_fini() and
xfrm6_tunnel_net_exit() use it. And, as ipcomp_destroy() itself is
blocking, it can use xfrm_state_put_sync() directly too.

Also rename xfrm_state_gc_destroy() to ___xfrm_state_destroy() to
reflect this change.

Fixes: b48c05ab5d32 ("xfrm: Fix warning in xfrm6_tunnel_net_exit.")
Reported-and-tested-by: syzbot+e9aebef558e3ed673934@syzkaller.appspotmail.com
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
---
 include/net/xfrm.h      | 12 +++++++++---
 net/ipv6/xfrm6_tunnel.c |  2 +-
 net/key/af_key.c        |  2 +-
 net/xfrm/xfrm_state.c   | 30 +++++++++++++++++++-----------
 net/xfrm/xfrm_user.c    |  2 +-
 5 files changed, 31 insertions(+), 17 deletions(-)

diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index 7298a53b9702..85386becbaea 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -853,7 +853,7 @@ static inline void xfrm_pols_put(struct xfrm_policy **pols, int npols)
 		xfrm_pol_put(pols[i]);
 }
 
-void __xfrm_state_destroy(struct xfrm_state *);
+void __xfrm_state_destroy(struct xfrm_state *, bool);
 
 static inline void __xfrm_state_put(struct xfrm_state *x)
 {
@@ -863,7 +863,13 @@ static inline void __xfrm_state_put(struct xfrm_state *x)
 static inline void xfrm_state_put(struct xfrm_state *x)
 {
 	if (refcount_dec_and_test(&x->refcnt))
-		__xfrm_state_destroy(x);
+		__xfrm_state_destroy(x, false);
+}
+
+static inline void xfrm_state_put_sync(struct xfrm_state *x)
+{
+	if (refcount_dec_and_test(&x->refcnt))
+		__xfrm_state_destroy(x, true);
 }
 
 static inline void xfrm_state_hold(struct xfrm_state *x)
@@ -1590,7 +1596,7 @@ struct xfrmk_spdinfo {
 
 struct xfrm_state *xfrm_find_acq_byseq(struct net *net, u32 mark, u32 seq);
 int xfrm_state_delete(struct xfrm_state *x);
-int xfrm_state_flush(struct net *net, u8 proto, bool task_valid);
+int xfrm_state_flush(struct net *net, u8 proto, bool task_valid, bool sync);
 int xfrm_dev_state_flush(struct net *net, struct net_device *dev, bool task_valid);
 void xfrm_sad_getinfo(struct net *net, struct xfrmk_sadinfo *si);
 void xfrm_spd_getinfo(struct net *net, struct xfrmk_spdinfo *si);
diff --git a/net/ipv6/xfrm6_tunnel.c b/net/ipv6/xfrm6_tunnel.c
index f5b4febeaa25..bc65db782bfb 100644
--- a/net/ipv6/xfrm6_tunnel.c
+++ b/net/ipv6/xfrm6_tunnel.c
@@ -344,8 +344,8 @@ static void __net_exit xfrm6_tunnel_net_exit(struct net *net)
 	struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net);
 	unsigned int i;
 
-	xfrm_state_flush(net, IPSEC_PROTO_ANY, false);
 	xfrm_flush_gc();
+	xfrm_state_flush(net, IPSEC_PROTO_ANY, false, true);
 
 	for (i = 0; i < XFRM6_TUNNEL_SPI_BYADDR_HSIZE; i++)
 		WARN_ON_ONCE(!hlist_empty(&xfrm6_tn->spi_byaddr[i]));
diff --git a/net/key/af_key.c b/net/key/af_key.c
index 655c787f9d54..637030f43b67 100644
--- a/net/key/af_key.c
+++ b/net/key/af_key.c
@@ -1783,7 +1783,7 @@ static int pfkey_flush(struct sock *sk, struct sk_buff *skb, const struct sadb_m
 	if (proto == 0)
 		return -EINVAL;
 
-	err = xfrm_state_flush(net, proto, true);
+	err = xfrm_state_flush(net, proto, true, false);
 	err2 = unicast_flush_resp(sk, hdr);
 	if (err || err2) {
 		if (err == -ESRCH) /* empty table - go quietly */
diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index 23c92891758a..1bb971f46fc6 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -432,7 +432,7 @@ void xfrm_state_free(struct xfrm_state *x)
 }
 EXPORT_SYMBOL(xfrm_state_free);
 
-static void xfrm_state_gc_destroy(struct xfrm_state *x)
+static void ___xfrm_state_destroy(struct xfrm_state *x)
 {
 	tasklet_hrtimer_cancel(&x->mtimer);
 	del_timer_sync(&x->rtimer);
@@ -474,7 +474,7 @@ static void xfrm_state_gc_task(struct work_struct *work)
 	synchronize_rcu();
 
 	hlist_for_each_entry_safe(x, tmp, &gc_list, gclist)
-		xfrm_state_gc_destroy(x);
+		___xfrm_state_destroy(x);
 }
 
 static enum hrtimer_restart xfrm_timer_handler(struct hrtimer *me)
@@ -598,14 +598,19 @@ struct xfrm_state *xfrm_state_alloc(struct net *net)
 }
 EXPORT_SYMBOL(xfrm_state_alloc);
 
-void __xfrm_state_destroy(struct xfrm_state *x)
+void __xfrm_state_destroy(struct xfrm_state *x, bool sync)
 {
 	WARN_ON(x->km.state != XFRM_STATE_DEAD);
 
-	spin_lock_bh(&xfrm_state_gc_lock);
-	hlist_add_head(&x->gclist, &xfrm_state_gc_list);
-	spin_unlock_bh(&xfrm_state_gc_lock);
-	schedule_work(&xfrm_state_gc_work);
+	if (sync) {
+		synchronize_rcu();
+		___xfrm_state_destroy(x);
+	} else {
+		spin_lock_bh(&xfrm_state_gc_lock);
+		hlist_add_head(&x->gclist, &xfrm_state_gc_list);
+		spin_unlock_bh(&xfrm_state_gc_lock);
+		schedule_work(&xfrm_state_gc_work);
+	}
 }
 EXPORT_SYMBOL(__xfrm_state_destroy);
 
@@ -708,7 +713,7 @@ xfrm_dev_state_flush_secctx_check(struct net *net, struct net_device *dev, bool
 }
 #endif
 
-int xfrm_state_flush(struct net *net, u8 proto, bool task_valid)
+int xfrm_state_flush(struct net *net, u8 proto, bool task_valid, bool sync)
 {
 	int i, err = 0, cnt = 0;
 
@@ -730,7 +735,10 @@ int xfrm_state_flush(struct net *net, u8 proto, bool task_valid)
 				err = xfrm_state_delete(x);
 				xfrm_audit_state_delete(x, err ? 0 : 1,
 							task_valid);
-				xfrm_state_put(x);
+				if (sync)
+					xfrm_state_put_sync(x);
+				else
+					xfrm_state_put(x);
 				if (!err)
 					cnt++;
 
@@ -2215,7 +2223,7 @@ void xfrm_state_delete_tunnel(struct xfrm_state *x)
 		if (atomic_read(&t->tunnel_users) == 2)
 			xfrm_state_delete(t);
 		atomic_dec(&t->tunnel_users);
-		xfrm_state_put(t);
+		xfrm_state_put_sync(t);
 		x->tunnel = NULL;
 	}
 }
@@ -2375,8 +2383,8 @@ void xfrm_state_fini(struct net *net)
 	unsigned int sz;
 
 	flush_work(&net->xfrm.state_hash_work);
-	xfrm_state_flush(net, IPSEC_PROTO_ANY, false);
 	flush_work(&xfrm_state_gc_work);
+	xfrm_state_flush(net, IPSEC_PROTO_ANY, false, true);
 
 	WARN_ON(!list_empty(&net->xfrm.state_all));
 
diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index c6d26afcf89d..a131f9ff979e 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -1932,7 +1932,7 @@ static int xfrm_flush_sa(struct sk_buff *skb, struct nlmsghdr *nlh,
 	struct xfrm_usersa_flush *p = nlmsg_data(nlh);
 	int err;
 
-	err = xfrm_state_flush(net, p->proto, true);
+	err = xfrm_state_flush(net, p->proto, true, false);
 	if (err) {
 		if (err == -ESRCH) /* empty table */
 			return 0;
-- 
2.17.1

[PATCH 3/4] af_key: unconditionally clone on broadcast

[Steffen Klassert]

From: Sean Tranchetti <stranche@codeaurora.org>

Attempting to avoid cloning the skb when broadcasting by inflating
the refcount with sock_hold/sock_put while under RCU lock is dangerous
and violates RCU principles. It leads to subtle race conditions when
attempting to free the SKB, as we may reference sockets that have
already been freed by the stack.

Unable to handle kernel paging request at virtual address 6b6b6b6b6b6c4b
[006b6b6b6b6b6c4b] address between user and kernel address ranges
Internal error: Oops: 96000004 [#1] PREEMPT SMP
task: fffffff78f65b380 task.stack: ffffff8049a88000
pc : sock_rfree+0x38/0x6c
lr : skb_release_head_state+0x6c/0xcc
Process repro (pid: 7117, stack limit = 0xffffff8049a88000)
Call trace:
	sock_rfree+0x38/0x6c
	skb_release_head_state+0x6c/0xcc
	skb_release_all+0x1c/0x38
	__kfree_skb+0x1c/0x30
	kfree_skb+0xd0/0xf4
	pfkey_broadcast+0x14c/0x18c
	pfkey_sendmsg+0x1d8/0x408
	sock_sendmsg+0x44/0x60
	___sys_sendmsg+0x1d0/0x2a8
	__sys_sendmsg+0x64/0xb4
	SyS_sendmsg+0x34/0x4c
	el0_svc_naked+0x34/0x38
Kernel panic - not syncing: Fatal exception

Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Sean Tranchetti <stranche@codeaurora.org>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
---
 net/key/af_key.c | 40 +++++++++++++++-------------------------
 1 file changed, 15 insertions(+), 25 deletions(-)

diff --git a/net/key/af_key.c b/net/key/af_key.c
index 637030f43b67..5651c29cb5bd 100644
--- a/net/key/af_key.c
+++ b/net/key/af_key.c
@@ -196,30 +196,22 @@ static int pfkey_release(struct socket *sock)
 	return 0;
 }
 
-static int pfkey_broadcast_one(struct sk_buff *skb, struct sk_buff **skb2,
-			       gfp_t allocation, struct sock *sk)
+static int pfkey_broadcast_one(struct sk_buff *skb, gfp_t allocation,
+			       struct sock *sk)
 {
 	int err = -ENOBUFS;
 
-	sock_hold(sk);
-	if (*skb2 == NULL) {
-		if (refcount_read(&skb->users) != 1) {
-			*skb2 = skb_clone(skb, allocation);
-		} else {
-			*skb2 = skb;
-			refcount_inc(&skb->users);
-		}
-	}
-	if (*skb2 != NULL) {
-		if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf) {
-			skb_set_owner_r(*skb2, sk);
-			skb_queue_tail(&sk->sk_receive_queue, *skb2);
-			sk->sk_data_ready(sk);
-			*skb2 = NULL;
-			err = 0;
-		}
+	if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf)
+		return err;
+
+	skb = skb_clone(skb, allocation);
+
+	if (skb) {
+		skb_set_owner_r(skb, sk);
+		skb_queue_tail(&sk->sk_receive_queue, skb);
+		sk->sk_data_ready(sk);
+		err = 0;
 	}
-	sock_put(sk);
 	return err;
 }
 
@@ -234,7 +226,6 @@ static int pfkey_broadcast(struct sk_buff *skb, gfp_t allocation,
 {
 	struct netns_pfkey *net_pfkey = net_generic(net, pfkey_net_id);
 	struct sock *sk;
-	struct sk_buff *skb2 = NULL;
 	int err = -ESRCH;
 
 	/* XXX Do we need something like netlink_overrun?  I think
@@ -253,7 +244,7 @@ static int pfkey_broadcast(struct sk_buff *skb, gfp_t allocation,
 		 * socket.
 		 */
 		if (pfk->promisc)
-			pfkey_broadcast_one(skb, &skb2, GFP_ATOMIC, sk);
+			pfkey_broadcast_one(skb, GFP_ATOMIC, sk);
 
 		/* the exact target will be processed later */
 		if (sk == one_sk)
@@ -268,7 +259,7 @@ static int pfkey_broadcast(struct sk_buff *skb, gfp_t allocation,
 				continue;
 		}
 
-		err2 = pfkey_broadcast_one(skb, &skb2, GFP_ATOMIC, sk);
+		err2 = pfkey_broadcast_one(skb, GFP_ATOMIC, sk);
 
 		/* Error is cleared after successful sending to at least one
 		 * registered KM */
@@ -278,9 +269,8 @@ static int pfkey_broadcast(struct sk_buff *skb, gfp_t allocation,
 	rcu_read_unlock();
 
 	if (one_sk != NULL)
-		err = pfkey_broadcast_one(skb, &skb2, allocation, one_sk);
+		err = pfkey_broadcast_one(skb, allocation, one_sk);
 
-	kfree_skb(skb2);
 	kfree_skb(skb);
 	return err;
 }
-- 
2.17.1

[PATCH 4/4] xfrm: Fix inbound traffic via XFRM interfaces across network namespaces

[Steffen Klassert]

From: Tobias Brunner <tobias@strongswan.org>

After moving an XFRM interface to another namespace it stays associated
with the original namespace (net in `struct xfrm_if` and the list keyed
with `xfrmi_net_id`), allowing processes in the new namespace to use
SAs/policies that were created in the original namespace.  For instance,
this allows a keying daemon in one namespace to establish IPsec SAs for
other namespaces without processes there having access to the keys or IKE
credentials.

This worked fine for outbound traffic, however, for inbound traffic the
lookup for the interfaces and the policies used the incorrect namespace
(the one the XFRM interface was moved to).

Fixes: f203b76d7809 ("xfrm: Add virtual xfrm interfaces")
Signed-off-by: Tobias Brunner <tobias@strongswan.org>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
---
 net/xfrm/xfrm_interface.c | 4 ++--
 net/xfrm/xfrm_policy.c    | 4 +++-
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/net/xfrm/xfrm_interface.c b/net/xfrm/xfrm_interface.c
index 6be8c7df15bb..dbb3c1945b5c 100644
--- a/net/xfrm/xfrm_interface.c
+++ b/net/xfrm/xfrm_interface.c
@@ -76,10 +76,10 @@ static struct xfrm_if *xfrmi_decode_session(struct sk_buff *skb)
 	int ifindex;
 	struct xfrm_if *xi;
 
-	if (!skb->dev)
+	if (!secpath_exists(skb) || !skb->dev)
 		return NULL;
 
-	xfrmn = net_generic(dev_net(skb->dev), xfrmi_net_id);
+	xfrmn = net_generic(xs_net(xfrm_input_state(skb)), xfrmi_net_id);
 	ifindex = skb->dev->ifindex;
 
 	for_each_xfrmi_rcu(xfrmn->xfrmi[0], xi) {
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index ba0a4048c846..8d1a898d0ba5 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -3314,8 +3314,10 @@ int __xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb,
 
 	if (ifcb) {
 		xi = ifcb->decode_session(skb);
-		if (xi)
+		if (xi) {
 			if_id = xi->p.if_id;
+			net = xi->net;
+		}
 	}
 	rcu_read_unlock();
 
-- 
2.17.1

Re: pull request (net): ipsec 2019-02-21

[David Miller]

From: Steffen Klassert <steffen.klassert@secunet.com>
Date: Thu, 21 Feb 2019 09:22:00 +0100

> 1) Don't do TX bytes accounting for the esp trailer when sending
>    from a request socket as this will result in an out of bounds
>    memory write. From Martin Willi.
> 
> 2) Destroy xfrm_state synchronously on net exit path to
>    avoid nested gc flush callbacks that may trigger a
>    warning in xfrm6_tunnel_net_exit(). From Cong Wang.
> 
> 3) Do an unconditionally clone in pfkey_broadcast_one()
>    to avoid a race when freeing the skb.
>    From Sean Tranchetti.
> 
> 4) Fix inbound traffic via XFRM interfaces across network
>    namespaces. We did the lookup for interfaces and policies
>    in the wrong namespace. From Tobias Brunner.
> 
> Please pull or let me know if there are problems.

Pulled, thanks.