From 7d460db953d6d205e4c8ecc2017aea1ec22b6c9a Mon Sep 17 00:00:00 2001 From: Daniel Lezcano Date: Fri, 18 Jan 2008 23:52:35 -0800 Subject: [PATCH] [IPV6]: Fix ip6_frag ctl Alexey Dobriyan reported an oops when unsharing the network indefinitely inside a loop. This is because the ip6_frag is not per namespace while the ctls are. That happens at the fragment timer expiration: inet_frag_secret_rebuild function is called and this one restarts the timer using the value stored inside the sysctl field. "mod_timer(&f->secret_timer, now + f->ctl->secret_interval);" When the network is unshared, ip6_frag.ctl is initialized with the new sysctl instances, but ip6_frag has only one instance. A race in this case will appear because f->ctl can be modified during the read access in the timer callback. Until the ip6_frag is not per namespace, I discard the assignation to the ctl field of ip6_frags in ip6_frag_sysctl_init when the network namespace is not the init net. Signed-off-by: Daniel Lezcano Signed-off-by: David S. Miller --- net/ipv6/reassembly.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/ipv6/reassembly.c b/net/ipv6/reassembly.c index 5cd0bc693a..4dfcddc871 100644 --- a/net/ipv6/reassembly.c +++ b/net/ipv6/reassembly.c @@ -627,6 +627,9 @@ static struct inet6_protocol frag_protocol = void ipv6_frag_sysctl_init(struct net *net) { + if (net != &init_net) + return; + ip6_frags.ctl = &net->ipv6.sysctl.frags; } -- 2.39.5