From edbe69ef2c90fc86998a74b08319a01c508bd497 Mon Sep 17 00:00:00 2001 From: Roman Gushchin Date: Fri, 2 Feb 2018 15:26:57 +0000 Subject: Revert "defer call to mem_cgroup_sk_alloc()" This patch effectively reverts commit 9f1c2674b328 ("net: memcontrol: defer call to mem_cgroup_sk_alloc()"). Moving mem_cgroup_sk_alloc() to the inet_csk_accept() completely breaks memcg socket memory accounting, as packets received before memcg pointer initialization are not accounted and are causing refcounting underflow on socket release. Actually the free-after-use problem was fixed by commit c0576e397508 ("net: call cgroup_sk_alloc() earlier in sk_clone_lock()") for the cgroup pointer. So, let's revert it and call mem_cgroup_sk_alloc() just before cgroup_sk_alloc(). This is safe, as we hold a reference to the socket we're cloning, and it holds a reference to the memcg. Also, let's drop BUG_ON(mem_cgroup_is_root()) check from mem_cgroup_sk_alloc(). I see no reasons why bumping the root memcg counter is a good reason to panic, and there are no realistic ways to hit it. Signed-off-by: Roman Gushchin Cc: Eric Dumazet Cc: David S. Miller Cc: Johannes Weiner Cc: Tejun Heo Signed-off-by: David S. Miller --- net/ipv4/inet_connection_sock.c | 1 - 1 file changed, 1 deletion(-) (limited to 'net/ipv4/inet_connection_sock.c') diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c index 12410ec6f7f7..881ac6d046f2 100644 --- a/net/ipv4/inet_connection_sock.c +++ b/net/ipv4/inet_connection_sock.c @@ -475,7 +475,6 @@ struct sock *inet_csk_accept(struct sock *sk, int flags, int *err, bool kern) } spin_unlock_bh(&queue->fastopenq.lock); } - mem_cgroup_sk_alloc(newsk); out: release_sock(sk); if (req) -- cgit v1.2.3-59-g8ed1b