linux.git/net/l2tp, branch v5.15

net/l2tp: Fix reference count leak in l2tp_udp_recv_core

2021-09-09T10:00:20+00:00

The reference count leak issue may take place in an error handling
path. If both conditions of tunnel->version == L2TP_HDR_VER_3 and the
return value of l2tp_v3_ensure_opt_in_linear is nonzero, the function
would directly jump to label invalid, without decrementing the reference
count of the l2tp_session object session increased earlier by
l2tp_tunnel_get_session(). This may result in refcount leaks.

Fix this issue by decrease the reference count before jumping to the
label invalid.

Fixes: 4522a70db7aa ("l2tp: fix reading optional fields of L2TPv3")
Signed-off-by: Xiyu Yang 
Signed-off-by: Xin Xiong 
Signed-off-by: Xin Tan 
Signed-off-by: David S. Miller

l2tp: Fix spelling mistakes

2021-06-07T21:08:30+00:00

Fix some spelling mistakes in comments:
negociated  ==> negotiated
dont  ==> don't

Signed-off-by: Zheng Yongjun 
Signed-off-by: David S. Miller

net: Remove the member netns_ok

2021-05-17T22:29:35+00:00

Every protocol has the 'netns_ok' member and it is euqal to 1. The
'if (!prot->netns_ok)' always false in inet_add_protocol().

Signed-off-by: Yejune Deng 
Signed-off-by: David S. Miller

net: fix a concurrency bug in l2tp_tunnel_register()

2021-04-27T21:23:13+00:00

l2tp_tunnel_register() registers a tunnel without fully
initializing its attribute. This can allow another kernel thread
running l2tp_xmit_core() to access the uninitialized data and
then cause a kernel NULL pointer dereference error, as shown below.

Thread 1    Thread 2
//l2tp_tunnel_register()
list_add_rcu(&tunnel->list, &pn->l2tp_tunnel_list);
           //pppol2tp_connect()
           tunnel = l2tp_tunnel_get(sock_net(sk), info.tunnel_id);
           // Fetch the new tunnel
           ...
           //l2tp_xmit_core()
           struct sock *sk = tunnel->sock;
           ...
           bh_lock_sock(sk);
           //Null pointer error happens
tunnel->sock = sk;

Fix this bug by initializing tunnel->sock before adding the
tunnel into l2tp_tunnel_list.

Reviewed-by: Cong Wang 
Signed-off-by: Sishuai Gong 
Reported-by: Sishuai Gong 
Signed-off-by: David S. Miller

net: l2tp: Fix a typo

2021-03-22T20:17:49+00:00

s/verifed/verified/

Signed-off-by: Bhaskar Chowdhury 
Acked-by: Randy Dunlap 
Signed-off-by: David S. Miller

net: l2tp: reduce log level of messages in receive path, add counter instead

2021-03-04T00:55:02+00:00

Commit 5ee759cda51b ("l2tp: use standard API for warning log messages")
changed a number of warnings about invalid packets in the receive path
so that they are always shown, instead of only when a special L2TP debug
flag is set. Even with rate limiting these warnings can easily cause
significant log spam - potentially triggered by a malicious party
sending invalid packets on purpose.

In addition these warnings were noticed by projects like Tunneldigger [1],
which uses L2TP for its data path, but implements its own control
protocol (which is sufficiently different from L2TP data packets that it
would always be passed up to userspace even with future extensions of
L2TP).

Some of the warnings were already redundant, as l2tp_stats has a counter
for these packets. This commit adds one additional counter for invalid
packets that are passed up to userspace. Packets with unknown session are
not counted as invalid, as there is nothing wrong with the format of
these packets.

With the additional counter, all of these messages are either redundant
or benign, so we reduce them to pr_debug_ratelimited().

[1] https://github.com/wlanslovenija/tunneldigger/issues/160

Fixes: 5ee759cda51b ("l2tp: use standard API for warning log messages")
Signed-off-by: Matthias Schiffer 
Signed-off-by: David S. Miller

lsm,selinux: pass flowi_common instead of flowi to the LSM hooks

2020-11-23T23:36:21+00:00

As pointed out by Herbert in a recent related patch, the LSM hooks do
not have the necessary address family information to use the flowi
struct safely.  As none of the LSMs currently use any of the protocol
specific flowi information, replace the flowi pointers with pointers
to the address family independent flowi_common struct.

Reported-by: Herbert Xu 
Acked-by: James Morris 
Signed-off-by: Paul Moore

genetlink: move to smaller ops wherever possible

2020-10-03T02:11:11+00:00

Bulk of the genetlink users can use smaller ops, move them.

Signed-off-by: Jakub Kicinski 
Reviewed-by: Johannes Berg 
Signed-off-by: David S. Miller

l2tp: report rx cookie discards in netlink get

2020-09-29T20:26:36+00:00

When an L2TPv3 session receives a data frame with an incorrect cookie
l2tp_core logs a warning message and bumps a stats counter to reflect
the fact that the packet has been dropped.

However, the stats counter in question is missing from the l2tp_netlink
get message for tunnel and session instances.

Include the statistic in the netlink get response.

Signed-off-by: Tom Parkin 
Signed-off-by: David S. Miller

l2tp: fix up inconsistent rx/tx statistics

2020-09-18T21:36:54+00:00

Historically L2TP core statistics count the L2TP header in the
per-session and per-tunnel byte counts tracked for transmission and
receipt.

Now that l2tp_xmit_skb updates tx stats, it is necessary for
l2tp_xmit_core to pass out the length of the transmitted packet so that
the statistics can be updated correctly.

Signed-off-by: Tom Parkin 
Signed-off-by: David S. Miller