diff options
| author | Guillaume Nault <g.nault@alphalink.fr> | 2016-11-29 15:09:44 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-11-30 22:14:07 +0300 |
| commit | 0382a25af3c771a8e4d5e417d1834cbe28c2aaac (patch) | |
| tree | 91d6b49fc8dab4cb02312da66d018a72975bd408 /net/l2tp/l2tp_ip.c | |
| parent | bb83d62fa83405d7c325873a317c9374f98eedef (diff) | |
| download | linux-0382a25af3c771a8e4d5e417d1834cbe28c2aaac.tar.xz | |
l2tp: lock socket before checking flags in connect()
Socket flags aren't updated atomically, so the socket must be locked
while reading the SOCK_ZAPPED flag.
This issue exists for both l2tp_ip and l2tp_ip6. For IPv6, this patch
also brings error handling for __ip6_datagram_connect() failures.
Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/l2tp/l2tp_ip.c')
| -rw-r--r-- | net/l2tp/l2tp_ip.c | 19 |
1 files changed, 12 insertions, 7 deletions
diff --git a/net/l2tp/l2tp_ip.c b/net/l2tp/l2tp_ip.c index 982f6c44ea01..1f57094d3111 100644 --- a/net/l2tp/l2tp_ip.c +++ b/net/l2tp/l2tp_ip.c @@ -308,21 +308,24 @@ static int l2tp_ip_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len struct sockaddr_l2tpip *lsa = (struct sockaddr_l2tpip *) uaddr; int rc; - if (sock_flag(sk, SOCK_ZAPPED)) /* Must bind first - autobinding does not work */ - return -EINVAL; - if (addr_len < sizeof(*lsa)) return -EINVAL; if (ipv4_is_multicast(lsa->l2tp_addr.s_addr)) return -EINVAL; - rc = ip4_datagram_connect(sk, uaddr, addr_len); - if (rc < 0) - return rc; - lock_sock(sk); + /* Must bind first - autobinding does not work */ + if (sock_flag(sk, SOCK_ZAPPED)) { + rc = -EINVAL; + goto out_sk; + } + + rc = __ip4_datagram_connect(sk, uaddr, addr_len); + if (rc < 0) + goto out_sk; + l2tp_ip_sk(sk)->peer_conn_id = lsa->l2tp_conn_id; write_lock_bh(&l2tp_ip_lock); @@ -330,7 +333,9 @@ static int l2tp_ip_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len sk_add_bind_node(sk, &l2tp_ip_bind_table); write_unlock_bh(&l2tp_ip_lock); +out_sk: release_sock(sk); + return rc; } |