@@ -327,6 +327,7 @@ struct sock {
unsigned short sk_max_ack_backlog;
__u32 sk_priority;
#ifdef CONFIG_CGROUPS
+ pid_t sk_cgrp_owner;
__u32 sk_cgrp_prioidx;
#endif
struct pid *sk_peer_pid;
@@ -1537,6 +1538,9 @@ static inline void sock_orphan(struct sock *sk)
sock_set_flag(sk, SOCK_DEAD);
sk_set_socket(sk, NULL);
sk->sk_wq = NULL;
+#ifdef CONFIG_CGROUPS
+ sk->sk_cgrp_owner = 0;
+#endif
write_unlock_bh(&sk->sk_callback_lock);
}
@@ -1162,24 +1162,31 @@ static void sk_prot_free(struct proto *prot, struct sock *sk)
#ifdef CONFIG_CGROUPS
void sock_update_classid(struct sock *sk)
{
+ pid_t tpid;
u32 classid;
rcu_read_lock(); /* doing current task, which cannot vanish. */
classid = task_cls_classid(current);
+ tpid = task_pid_nr(current);
rcu_read_unlock();
- if (classid && classid != sk->sk_classid)
+
+ if ((tpid == sk->sk_cgrp_owner) &&
+ (classid && classid != sk->sk_classid))
sk->sk_classid = classid;
}
EXPORT_SYMBOL(sock_update_classid);
void sock_update_netprioidx(struct sock *sk)
{
+ pid_t tpid;
struct cgroup_netprio_state *state;
if (in_interrupt())
return;
rcu_read_lock();
+ tpid = task_pid_nr(current);
state = task_netprio_state(current);
- sk->sk_cgrp_prioidx = state ? state->prioidx : 0;
+ if (tpid == sk->sk_cgrp_owner)
+ sk->sk_cgrp_prioidx = state ? state->prioidx : 0;
rcu_read_unlock();
}
EXPORT_SYMBOL_GPL(sock_update_netprioidx);
@@ -1208,7 +1215,9 @@ struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
sock_lock_init(sk);
sock_net_set(sk, get_net(net));
atomic_set(&sk->sk_wmem_alloc, 1);
-
+#ifdef CONFIG_CGROUPS
+ sk->sk_cgrp_owner = task_pid_nr(current);
+#endif
sock_update_classid(sk);
sock_update_netprioidx(sk);
}
To prevent multiple processes that share a socket from fighting over the cgroup instance said socket belongs to, add a sk_cgrp_owner flag so that calls to sk_update_[classid/prioidx] only do something in the event that its the owning process updating them. This way only one pid is responsible for updating the sockets cgroup information. When that process releases the socket, set the owner pid to zero so as to prevent a future task that reuses the same pid from inheriting the socket erroneously Signed-off-by: Neil Horman <nhorman@tuxdriver.com> CC: Thomas Graf <tgraf@infradead.org> CC: "David S. Miller" <davem@davemloft.net> --- include/net/sock.h | 4 ++++ net/core/sock.c | 15 ++++++++++++--- 2 files changed, 16 insertions(+), 3 deletions(-)