diff options
| -rw-r--r-- | include/net/sock.h | 13 | ||||
| -rw-r--r-- | net/core/sock.c | 18 | ||||
| -rw-r--r-- | net/netlink/af_netlink.c | 18 |
3 files changed, 33 insertions, 16 deletions
diff --git a/include/net/sock.h b/include/net/sock.h index fd9876087651..39112e75411c 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -850,6 +850,7 @@ extern struct sock *sk_alloc(struct net *net, int family, gfp_t priority, struct proto *prot); extern void sk_free(struct sock *sk); +extern void sk_release_kernel(struct sock *sk); extern struct sock *sk_clone(const struct sock *sk, const gfp_t priority); @@ -1333,6 +1334,18 @@ static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb, int copied_e } #endif +/* + * Kernel sockets, f.e. rtnl or icmp_socket, are a part of a namespace. + * They should not hold a referrence to a namespace in order to allow + * to stop it. + * Sockets after sk_change_net should be released using sk_release_kernel + */ +static inline void sk_change_net(struct sock *sk, struct net *net) +{ + put_net(sk->sk_net); + sk->sk_net = net; +} + extern void sock_enable_timestamp(struct sock *sk); extern int sock_get_timestamp(struct sock *, struct timeval __user *); extern int sock_get_timestampns(struct sock *, struct timespec __user *); diff --git a/net/core/sock.c b/net/core/sock.c index 09cb3a74de7f..c71b645a78f0 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -987,6 +987,24 @@ void sk_free(struct sock *sk) sk_prot_free(sk->sk_prot_creator, sk); } +/* + * Last sock_put should drop referrence to sk->sk_net. It has already + * been dropped in sk_change_net. Taking referrence to stopping namespace + * is not an option. + * Take referrence to a socket to remove it from hash _alive_ and after that + * destroy it in the context of init_net. + */ +void sk_release_kernel(struct sock *sk) +{ + if (sk == NULL || sk->sk_socket == NULL) + return; + + sock_hold(sk); + sock_release(sk->sk_socket); + sk->sk_net = get_net(&init_net); + sock_put(sk); +} + struct sock *sk_clone(const struct sock *sk, const gfp_t priority) { struct sock *newsk; diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c index e6b636d53633..524e826bb976 100644 --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -1372,8 +1372,7 @@ netlink_kernel_create(struct net *net, int unit, unsigned int groups, goto out_sock_release_nosk; sk = sock->sk; - put_net(sk->sk_net); - sk->sk_net = net; + sk_change_net(sk, net); if (groups < 32) groups = 32; @@ -1421,20 +1420,7 @@ EXPORT_SYMBOL(netlink_kernel_create); void netlink_kernel_release(struct sock *sk) { - /* - * Last sock_put should drop referrence to sk->sk_net. It has already - * been dropped in netlink_kernel_create. Taking referrence to stopping - * namespace is not an option. - * Take referrence to a socket to remove it from netlink lookup table - * _alive_ and after that destroy it in the context of init_net. - */ - if (sk == NULL || sk->sk_socket == NULL) - return; - - sock_hold(sk); - sock_release(sk->sk_socket); - sk->sk_net = get_net(&init_net); - sock_put(sk); + sk_release_kernel(sk); } EXPORT_SYMBOL(netlink_kernel_release); |