diff options
Diffstat (limited to '')
| -rw-r--r-- | include/net/net_namespace.h | 10 | ||||
| -rw-r--r-- | net/ipv4/tcp.c | 3 | ||||
| -rw-r--r-- | net/ipv4/tcp_timer.c | 15 |
3 files changed, 28 insertions, 0 deletions
diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h index 10f99dafd5ac..049008493faf 100644 --- a/include/net/net_namespace.h +++ b/include/net/net_namespace.h @@ -223,6 +223,11 @@ int net_eq(const struct net *net1, const struct net *net2) return net1 == net2; } +static inline int check_net(const struct net *net) +{ + return atomic_read(&net->count) != 0; +} + void net_drop_ns(void *); #else @@ -247,6 +252,11 @@ int net_eq(const struct net *net1, const struct net *net2) return 1; } +static inline int check_net(const struct net *net) +{ + return 1; +} + #define net_drop_ns NULL #endif diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index f08eebe60446..8e053ad7cae2 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -2298,6 +2298,9 @@ adjudge_to_death: tcp_send_active_reset(sk, GFP_ATOMIC); __NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTONMEMORY); + } else if (!check_net(sock_net(sk))) { + /* Not possible to send reset; just close */ + tcp_set_state(sk, TCP_CLOSE); } } diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c index 968fda198376..388158c9d9f6 100644 --- a/net/ipv4/tcp_timer.c +++ b/net/ipv4/tcp_timer.c @@ -48,11 +48,19 @@ static void tcp_write_err(struct sock *sk) * to prevent DoS attacks. It is called when a retransmission timeout * or zero probe timeout occurs on orphaned socket. * + * Also close if our net namespace is exiting; in that case there is no + * hope of ever communicating again since all netns interfaces are already + * down (or about to be down), and we need to release our dst references, + * which have been moved to the netns loopback interface, so the namespace + * can finish exiting. This condition is only possible if we are a kernel + * socket, as those do not hold references to the namespace. + * * Criteria is still not confirmed experimentally and may change. * We kill the socket, if: * 1. If number of orphaned sockets exceeds an administratively configured * limit. * 2. If we have strong memory pressure. + * 3. If our net namespace is exiting. */ static int tcp_out_of_resources(struct sock *sk, bool do_reset) { @@ -81,6 +89,13 @@ static int tcp_out_of_resources(struct sock *sk, bool do_reset) __NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTONMEMORY); return 1; } + + if (!check_net(sock_net(sk))) { + /* Not possible to send reset; just close */ + tcp_done(sk); + return 1; + } + return 0; } |