diff options
author | Patrick McHardy <kaber@trash.net> | 2006-11-29 02:35:25 +0100 |
---|---|---|
committer | David S. Miller <davem@sunset.davemloft.net> | 2006-12-02 21:31:22 -0800 |
commit | 337fbc4166967a72c3cc71c597bdde7e6a8633ab (patch) | |
tree | 95b2d47e55db3991f66090525b7e28455a6ca39b /net/ipv4/netfilter/ip_nat_tftp.c | |
parent | 468ec44bd5a863736d955f78b8c38896f26864a1 (diff) |
[NETFILTER]: ip_conntrack: fix NAT helper unload races
The NAT helpr hooks are protected by RCU, but all of the
conntrack helpers test and use the global pointers instead
of copying them first using rcu_dereference()
Also replace synchronize_net() by synchronize_rcu() for clarity
since sychronizing only with packet receive processing is
insufficient to prevent races.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Diffstat (limited to 'net/ipv4/netfilter/ip_nat_tftp.c')
-rw-r--r-- | net/ipv4/netfilter/ip_nat_tftp.c | 9 |
1 files changed, 4 insertions, 5 deletions
diff --git a/net/ipv4/netfilter/ip_nat_tftp.c b/net/ipv4/netfilter/ip_nat_tftp.c index 94a78015451..604793536fc 100644 --- a/net/ipv4/netfilter/ip_nat_tftp.c +++ b/net/ipv4/netfilter/ip_nat_tftp.c @@ -55,15 +55,14 @@ static unsigned int help(struct sk_buff **pskb, static void __exit ip_nat_tftp_fini(void) { - ip_nat_tftp_hook = NULL; - /* Make sure noone calls it, meanwhile. */ - synchronize_net(); + rcu_assign_pointer(ip_nat_tftp_hook, NULL); + synchronize_rcu(); } static int __init ip_nat_tftp_init(void) { - BUG_ON(ip_nat_tftp_hook); - ip_nat_tftp_hook = help; + BUG_ON(rcu_dereference(ip_nat_tftp_hook)); + rcu_assign_pointer(ip_nat_tftp_hook, help); return 0; } |