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| author | Alexander Couzens <lynxis@fe80.eu> | 2015-09-28 11:32:42 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2015-09-28 22:39:10 -0700 |
| commit | 06a15f51cf3618e32a73871ee6a547ef7fd902b5 (patch) | |
| tree | 5d7f25db11b5b985c7366d8bf954aeca976f2b2b | |
| parent | 661dfc65f7981481ba2e31aaa702371e82336e56 (diff) | |
| download | linux-stable-06a15f51cf3618e32a73871ee6a547ef7fd902b5.tar.gz linux-stable-06a15f51cf3618e32a73871ee6a547ef7fd902b5.tar.bz2 linux-stable-06a15f51cf3618e32a73871ee6a547ef7fd902b5.zip | |
l2tp: protect tunnel->del_work by ref_count
There is a small chance that tunnel_free() is called before tunnel->del_work scheduled
resulting in a zero pointer dereference.
Signed-off-by: Alexander Couzens <lynxis@fe80.eu>
Acked-by: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/l2tp/l2tp_core.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c index f6b090df3930..afca2eb4dfa7 100644 --- a/net/l2tp/l2tp_core.c +++ b/net/l2tp/l2tp_core.c @@ -1319,7 +1319,7 @@ static void l2tp_tunnel_del_work(struct work_struct *work) tunnel = container_of(work, struct l2tp_tunnel, del_work); sk = l2tp_tunnel_sock_lookup(tunnel); if (!sk) - return; + goto out; sock = sk->sk_socket; @@ -1341,6 +1341,8 @@ static void l2tp_tunnel_del_work(struct work_struct *work) } l2tp_tunnel_sock_put(sk); +out: + l2tp_tunnel_dec_refcount(tunnel); } /* Create a socket for the tunnel, if one isn't set up by @@ -1636,8 +1638,13 @@ EXPORT_SYMBOL_GPL(l2tp_tunnel_create); */ int l2tp_tunnel_delete(struct l2tp_tunnel *tunnel) { + l2tp_tunnel_inc_refcount(tunnel); l2tp_tunnel_closeall(tunnel); - return (false == queue_work(l2tp_wq, &tunnel->del_work)); + if (false == queue_work(l2tp_wq, &tunnel->del_work)) { + l2tp_tunnel_dec_refcount(tunnel); + return 1; + } + return 0; } EXPORT_SYMBOL_GPL(l2tp_tunnel_delete); |