From fbb1fb4ad415cb31ce944f65a5ca700aaf73a227 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Sun, 8 Oct 2017 21:44:52 -0700 Subject: net: defer call to cgroup_sk_alloc() sk_clone_lock() might run while TCP/DCCP listener already vanished. In order to prevent use after free, it is better to defer cgroup_sk_alloc() to the point we know both parent and child exist, and from process context. Fixes: e994b2f0fb92 ("tcp: do not lock listener to process SYN packets") Signed-off-by: Eric Dumazet Cc: Johannes Weiner Cc: Tejun Heo Signed-off-by: David S. Miller --- kernel/cgroup/cgroup.c | 11 ----------- 1 file changed, 11 deletions(-) (limited to 'kernel') diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index 44857278eb8a..3380a3e49af5 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -5709,17 +5709,6 @@ void cgroup_sk_alloc(struct sock_cgroup_data *skcd) if (cgroup_sk_alloc_disabled) return; - /* Socket clone path */ - if (skcd->val) { - /* - * We might be cloning a socket which is left in an empty - * cgroup and the cgroup might have already been rmdir'd. - * Don't use cgroup_get_live(). - */ - cgroup_get(sock_cgroup_ptr(skcd)); - return; - } - rcu_read_lock(); while (true) { -- cgit v1.2.3