linux-stable.git/net/l2tp, branch v4.9.44

l2tp: consider '::' as wildcard address in l2tp_ip6 socket lookup

2017-08-07T01:59:46+00:00

[ Upstream commit 97b84fd6d91766ea57dcc350d78f42639e011c30 ]

An L2TP socket bound to the unspecified address should match with any
address. If not, it can't receive any packet and __l2tp_ip6_bind_lookup()
can't prevent another socket from binding on the same device/tunnel ID.

While there, rename the 'addr' variable to 'sk_laddr' (local addr), to
make following patch clearer.

Signed-off-by: Guillaume Nault 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

l2tp: take a reference on sessions used in genetlink handlers

2017-07-05T12:40:19+00:00

commit 2777e2ab5a9cf2b4524486c6db1517a6ded25261 upstream.

Callers of l2tp_nl_session_find() need to hold a reference on the
returned session since there's no guarantee that it isn't going to
disappear from under them.

Relying on the fact that no l2tp netlink message may be processed
concurrently isn't enough: sessions can be deleted by other means
(e.g. by closing the PPPOL2TP socket of a ppp pseudowire).

l2tp_nl_cmd_session_delete() is a bit special: it runs a callback
function that may require a previous call to session->ref(). In
particular, for ppp pseudowires, the callback is l2tp_session_delete(),
which then calls pppol2tp_session_close() and dereferences the PPPOL2TP
socket. The socket might already be gone at the moment
l2tp_session_delete() calls session->ref(), so we need to take a
reference during the session lookup. So we need to pass the do_ref
variable down to l2tp_session_get() and l2tp_session_get_by_ifname().

Since all callers have to be updated, l2tp_session_find_by_ifname() and
l2tp_nl_session_find() are renamed to reflect their new behaviour.

Fixes: 309795f4bec2 ("l2tp: Add netlink control API for L2TP")
Signed-off-by: Guillaume Nault 
Signed-off-by: David S. Miller 
Signed-off-by: Amit Pundir 
Signed-off-by: Greg Kroah-Hartman

l2tp: hold session while sending creation notifications

2017-07-05T12:40:18+00:00

commit 5e6a9e5a3554a5b3db09cdc22253af1849c65dff upstream.

l2tp_session_find() doesn't take any reference on the returned session.
Therefore, the session may disappear while sending the notification.

Use l2tp_session_get() instead and decrement session's refcount once
the notification is sent.

Fixes: 33f72e6f0c67 ("l2tp : multicast notification to the registered listeners")
Signed-off-by: Guillaume Nault 
Signed-off-by: David S. Miller 
Signed-off-by: Amit Pundir 
Signed-off-by: Greg Kroah-Hartman

l2tp: fix duplicate session creation

2017-07-05T12:40:18+00:00

commit dbdbc73b44782e22b3b4b6e8b51e7a3d245f3086 upstream.

l2tp_session_create() relies on its caller for checking for duplicate
sessions. This is racy since a session can be concurrently inserted
after the caller's verification.

Fix this by letting l2tp_session_create() verify sessions uniqueness
upon insertion. Callers need to be adapted to check for
l2tp_session_create()'s return code instead of calling
l2tp_session_find().

pppol2tp_connect() is a bit special because it has to work on existing
sessions (if they're not connected) or to create a new session if none
is found. When acting on a preexisting session, a reference must be
held or it could go away on us. So we have to use l2tp_session_get()
instead of l2tp_session_find() and drop the reference before exiting.

Fixes: d9e31d17ceba ("l2tp: Add L2TP ethernet pseudowire support")
Fixes: fd558d186df2 ("l2tp: Split pppol2tp patch into separate l2tp and ppp parts")
Signed-off-by: Guillaume Nault 
Signed-off-by: David S. Miller 
Signed-off-by: Amit Pundir 
Signed-off-by: Greg Kroah-Hartman

l2tp: ensure session can't get removed during pppol2tp_session_ioctl()

2017-07-05T12:40:18+00:00

commit 57377d63547861919ee634b845c7caa38de4a452 upstream.

Holding a reference on session is required before calling
pppol2tp_session_ioctl(). The session could get freed while processing the
ioctl otherwise. Since pppol2tp_session_ioctl() uses the session's socket,
we also need to take a reference on it in l2tp_session_get().

Fixes: fd558d186df2 ("l2tp: Split pppol2tp patch into separate l2tp and ppp parts")
Signed-off-by: Guillaume Nault 
Signed-off-by: David S. Miller 
Signed-off-by: Amit Pundir 
Signed-off-by: Greg Kroah-Hartman

l2tp: fix race in l2tp_recv_common()

2017-07-05T12:40:18+00:00

commit 61b9a047729bb230978178bca6729689d0c50ca2 upstream.

Taking a reference on sessions in l2tp_recv_common() is racy; this
has to be done by the callers.

To this end, a new function is required (l2tp_session_get()) to
atomically lookup a session and take a reference on it. Callers then
have to manually drop this reference.

Fixes: fd558d186df2 ("l2tp: Split pppol2tp patch into separate l2tp and ppp parts")
Signed-off-by: Guillaume Nault 
Signed-off-by: David S. Miller 
Signed-off-by: Amit Pundir 
Signed-off-by: Greg Kroah-Hartman

l2tp: fix PPP pseudo-wire auto-loading

2017-05-03T15:36:35+00:00

[ Upstream commit 249ee819e24c180909f43c1173c8ef6724d21faf ]

PPP pseudo-wire type is 7 (11 is L2TP_PWTYPE_IP).

Fixes: f1f39f911027 ("l2tp: auto load type modules")
Signed-off-by: Guillaume Nault 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

l2tp: take reference on sessions being dumped

2017-05-03T15:36:35+00:00

[ Upstream commit e08293a4ccbcc993ded0fdc46f1e57926b833d63 ]

Take a reference on the sessions returned by l2tp_session_find_nth()
(and rename it l2tp_session_get_nth() to reflect this change), so that
caller is assured that the session isn't going to disappear while
processing it.

For procfs and debugfs handlers, the session is held in the .start()
callback and dropped in .show(). Given that pppol2tp_seq_session_show()
dereferences the associated PPPoL2TP socket and that
l2tp_dfs_seq_session_show() might call pppol2tp_show(), we also need to
call the session's .ref() callback to prevent the socket from going
away from under us.

Fixes: fd558d186df2 ("l2tp: Split pppol2tp patch into separate l2tp and ppp parts")
Fixes: 0ad6614048cf ("l2tp: Add debugfs files for dumping l2tp debug info")
Fixes: 309795f4bec2 ("l2tp: Add netlink control API for L2TP")
Signed-off-by: Guillaume Nault 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

l2tp: purge socket queues in the .destruct() callback

2017-05-03T15:36:35+00:00

[ Upstream commit e91793bb615cf6cdd59c0b6749fe173687bb0947 ]

The Rx path may grab the socket right before pppol2tp_release(), but
nothing guarantees that it will enqueue packets before
skb_queue_purge(). Therefore, the socket can be destroyed without its
queues fully purged.

Fix this by purging queues in pppol2tp_session_destruct() where we're
guaranteed nothing is still referencing the socket.

Fixes: 9e9cb6221aa7 ("l2tp: fix userspace reception on plain L2TP sockets")
Signed-off-by: Guillaume Nault 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

l2tp: hold tunnel socket when handling control frames in l2tp_ip and l2tp_ip6

2017-05-03T15:36:35+00:00

[ Upstream commit 94d7ee0baa8b764cf64ad91ed69464c1a6a0066b ]

The code following l2tp_tunnel_find() expects that a new reference is
held on sk. Either sk_receive_skb() or the discard_put error path will
drop a reference from the tunnel's socket.

This issue exists in both l2tp_ip and l2tp_ip6.

Fixes: a3c18422a4b4 ("l2tp: hold socket before dropping lock in l2tp_ip{, 6}_recv()")
Signed-off-by: Guillaume Nault 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman