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| author | David S. Miller <davem@davemloft.net> | 2011-05-08 13:45:20 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2011-05-08 13:45:20 -0700 |
| commit | 6af88da14ee284aaad6e4326da09a89191ab6165 (patch) | |
| tree | bde47277368279454abff9a860be9292556c7089 /net/l2tp | |
| parent | 2f16270f41e1499e23e6be25c51be87d950ffc91 (diff) | |
| download | lwn-6af88da14ee284aaad6e4326da09a89191ab6165.tar.gz lwn-6af88da14ee284aaad6e4326da09a89191ab6165.zip | |
l2tp: Fix locking in l2tp_core.c
l2tp_xmit_skb() must take the socket lock. It makes use of ip_queue_xmit()
which expects to execute in a socket atomic context.
Since we execute this function in software interrupts, we cannot use the
usual lock_sock()/release_sock() sequence, instead we have to use
bh_lock_sock() and see if a user has the socket locked, and if so drop
the packet.
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/l2tp')
| -rw-r--r-- | net/l2tp/l2tp_core.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c index c64ce0a0bb03..78530299ae38 100644 --- a/net/l2tp/l2tp_core.c +++ b/net/l2tp/l2tp_core.c @@ -1060,6 +1060,12 @@ int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb, int hdr_len IPSKB_REROUTED); nf_reset(skb); + bh_lock_sock(sk); + if (sock_owned_by_user(sk)) { + dev_kfree_skb(skb); + goto out_unlock; + } + /* Get routing info from the tunnel socket */ skb_dst_drop(skb); skb_dst_set(skb, dst_clone(__sk_dst_get(sk))); @@ -1106,6 +1112,8 @@ int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb, int hdr_len l2tp_skb_set_owner_w(skb, sk); l2tp_xmit_core(session, skb, data_len); +out_unlock: + bh_unlock_sock(sk); abort: return 0; |