[PATCH AUTOSEL 4.9 08/19] vsock/virtio: fix kernel panic after device hot-unplug

[PATCH AUTOSEL 4.9 08/19] vsock/virtio: fix kernel panic after device hot-unplug

[Sasha Levin]

From: Stefano Garzarella <sgarzare@redhat.com>

[ Upstream commit 22b5c0b63f32568e130fa2df4ba23efce3eb495b ]

virtio_vsock_remove() invokes the vsock_core_exit() also if there
are opened sockets for the AF_VSOCK protocol family. In this way
the vsock "transport" pointer is set to NULL, triggering the
kernel panic at the first socket activity.

This patch move the vsock_core_init()/vsock_core_exit() in the
virtio_vsock respectively in module_init and module_exit functions,
that cannot be invoked until there are open sockets.

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1609699
Reported-by: Yan Fu <yafu@redhat.com>
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/vmw_vsock/virtio_transport.c | 26 ++++++++++++++++++--------
 1 file changed, 18 insertions(+), 8 deletions(-)

diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c
index 936d7eee62d03..6cbc08d82e7fd 100644
--- a/net/vmw_vsock/virtio_transport.c
+++ b/net/vmw_vsock/virtio_transport.c
@@ -71,6 +71,9 @@ static u32 virtio_transport_get_local_cid(void)
 {
 	struct virtio_vsock *vsock = virtio_vsock_get();
 
+	if (!vsock)
+		return VMADDR_CID_ANY;
+
 	return vsock->guest_cid;
 }
 
@@ -495,10 +498,6 @@ static int virtio_vsock_probe(struct virtio_device *vdev)
 
 	virtio_vsock_update_guest_cid(vsock);
 
-	ret = vsock_core_init(&virtio_transport.transport);
-	if (ret < 0)
-		goto out_vqs;
-
 	vsock->rx_buf_nr = 0;
 	vsock->rx_buf_max_nr = 0;
 	atomic_set(&vsock->queued_replies, 0);
@@ -526,8 +525,6 @@ static int virtio_vsock_probe(struct virtio_device *vdev)
 	mutex_unlock(&the_virtio_vsock_mutex);
 	return 0;
 
-out_vqs:
-	vsock->vdev->config->del_vqs(vsock->vdev);
 out:
 	kfree(vsock);
 	mutex_unlock(&the_virtio_vsock_mutex);
@@ -567,7 +564,6 @@ static void virtio_vsock_remove(struct virtio_device *vdev)
 
 	mutex_lock(&the_virtio_vsock_mutex);
 	the_virtio_vsock = NULL;
-	vsock_core_exit();
 	mutex_unlock(&the_virtio_vsock_mutex);
 
 	vdev->config->del_vqs(vdev);
@@ -600,14 +596,28 @@ static int __init virtio_vsock_init(void)
 	virtio_vsock_workqueue = alloc_workqueue("virtio_vsock", 0, 0);
 	if (!virtio_vsock_workqueue)
 		return -ENOMEM;
+
 	ret = register_virtio_driver(&virtio_vsock_driver);
 	if (ret)
-		destroy_workqueue(virtio_vsock_workqueue);
+		goto out_wq;
+
+	ret = vsock_core_init(&virtio_transport.transport);
+	if (ret)
+		goto out_vdr;
+
+	return 0;
+
+out_vdr:
+	unregister_virtio_driver(&virtio_vsock_driver);
+out_wq:
+	destroy_workqueue(virtio_vsock_workqueue);
 	return ret;
+
 }
 
 static void __exit virtio_vsock_exit(void)
 {
+	vsock_core_exit();
 	unregister_virtio_driver(&virtio_vsock_driver);
 	destroy_workqueue(virtio_vsock_workqueue);
 }
-- 
2.19.1

[PATCH AUTOSEL 4.9 09/19] vsock/virtio: reset connected sockets on device removal

[Sasha Levin]

From: Stefano Garzarella <sgarzare@redhat.com>

[ Upstream commit 85965487abc540368393a15491e6e7fcd230039d ]

When the virtio transport device disappear, we should reset all
connected sockets in order to inform the users.

Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/vmw_vsock/virtio_transport.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c
index 6cbc08d82e7fd..f66a6010ae075 100644
--- a/net/vmw_vsock/virtio_transport.c
+++ b/net/vmw_vsock/virtio_transport.c
@@ -541,6 +541,9 @@ static void virtio_vsock_remove(struct virtio_device *vdev)
 	flush_work(&vsock->event_work);
 	flush_work(&vsock->send_pkt_work);
 
+	/* Reset all connected sockets when the device disappear */
+	vsock_for_each_connected_socket(virtio_vsock_reset_sock);
+
 	vdev->config->reset(vdev);
 
 	mutex_lock(&vsock->rx_lock);
-- 
2.19.1

[PATCH AUTOSEL 4.9 13/19] netfilter: nf_nat: skip nat clash resolution for same-origin entries

[Sasha Levin]

From: Martynas Pumputis <martynas@weave.works>

[ Upstream commit 4e35c1cb9460240e983a01745b5f29fe3a4d8e39 ]

It is possible that two concurrent packets originating from the same
socket of a connection-less protocol (e.g. UDP) can end up having
different IP_CT_DIR_REPLY tuples which results in one of the packets
being dropped.

To illustrate this, consider the following simplified scenario:

1. Packet A and B are sent at the same time from two different threads
   by same UDP socket.  No matching conntrack entry exists yet.
   Both packets cause allocation of a new conntrack entry.
2. get_unique_tuple gets called for A.  No clashing entry found.
   conntrack entry for A is added to main conntrack table.
3. get_unique_tuple is called for B and will find that the reply
   tuple of B is already taken by A.
   It will allocate a new UDP source port for B to resolve the clash.
4. conntrack entry for B cannot be added to main conntrack table
   because its ORIGINAL direction is clashing with A and the REPLY
   directions of A and B are not the same anymore due to UDP source
   port reallocation done in step 3.

This patch modifies nf_conntrack_tuple_taken so it doesn't consider
colliding reply tuples if the IP_CT_DIR_ORIGINAL tuples are equal.

[ Florian: simplify patch to not use .allow_clash setting
  and always ignore identical flows ]

Signed-off-by: Martynas Pumputis <martynas@weave.works>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/netfilter/nf_conntrack_core.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index 19b3f4fbea520..df1d5618b008f 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -855,6 +855,22 @@ nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
 		}
 
 		if (nf_ct_key_equal(h, tuple, zone, net)) {
+			/* Tuple is taken already, so caller will need to find
+			 * a new source port to use.
+			 *
+			 * Only exception:
+			 * If the *original tuples* are identical, then both
+			 * conntracks refer to the same flow.
+			 * This is a rare situation, it can occur e.g. when
+			 * more than one UDP packet is sent from same socket
+			 * in different threads.
+			 *
+			 * Let nf_ct_resolve_clash() deal with this later.
+			 */
+			if (nf_ct_tuple_equal(&ignored_conntrack->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
+					      &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple))
+				continue;
+
 			NF_CT_STAT_INC_ATOMIC(net, found);
 			rcu_read_unlock();
 			return 1;
-- 
2.19.1