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| author | David S. Miller <davem@davemloft.net> | 2011-05-08 13:39:01 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2011-05-08 13:39:01 -0700 |
| commit | 2f16270f41e1499e23e6be25c51be87d950ffc91 (patch) | |
| tree | b3d40d33c4ff5470eb3642d44064fe4ec4caff92 /net/l2tp | |
| parent | da905bd1d5a6480d206f4b3dc61243f95adfae2c (diff) | |
| download | lwn-2f16270f41e1499e23e6be25c51be87d950ffc91.tar.gz lwn-2f16270f41e1499e23e6be25c51be87d950ffc91.zip | |
l2tp: Fix locking in l2tp_ip.c
Both l2tp_ip_connect() and l2tp_ip_sendmsg() must take the socket
lock. They both modify socket state non-atomically, and in particular
l2tp_ip_sendmsg() increments socket private counters without using
atomic operations.
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/l2tp')
| -rw-r--r-- | net/l2tp/l2tp_ip.c | 19 |
1 files changed, 15 insertions, 4 deletions
diff --git a/net/l2tp/l2tp_ip.c b/net/l2tp/l2tp_ip.c index 81899600abe2..bd0cc0b8f32f 100644 --- a/net/l2tp/l2tp_ip.c +++ b/net/l2tp/l2tp_ip.c @@ -311,6 +311,8 @@ static int l2tp_ip_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len if (lsa->l2tp_family != AF_INET) goto out; + lock_sock(sk); + sk_dst_reset(sk); oif = sk->sk_bound_dev_if; @@ -356,6 +358,7 @@ static int l2tp_ip_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len rc = 0; out: + release_sock(sk); return rc; } @@ -420,18 +423,23 @@ static int l2tp_ip_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *m int connected = 0; __be32 daddr; + lock_sock(sk); + + rc = -ENOTCONN; if (sock_flag(sk, SOCK_DEAD)) - return -ENOTCONN; + goto out; /* Get and verify the address. */ if (msg->msg_name) { struct sockaddr_l2tpip *lip = (struct sockaddr_l2tpip *) msg->msg_name; + rc = -EINVAL; if (msg->msg_namelen < sizeof(*lip)) - return -EINVAL; + goto out; if (lip->l2tp_family != AF_INET) { + rc = -EAFNOSUPPORT; if (lip->l2tp_family != AF_UNSPEC) - return -EAFNOSUPPORT; + goto out; } daddr = lip->l2tp_addr.s_addr; @@ -510,12 +518,15 @@ error: lsa->tx_errors++; } +out: + release_sock(sk); return rc; no_route: IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTNOROUTES); kfree_skb(skb); - return -EHOSTUNREACH; + rc = -EHOSTUNREACH; + goto out; } static int l2tp_ip_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, |