Commit f2f316e2 authored by Kuniyuki Iwashima's avatar Kuniyuki Iwashima Committed by David S. Miller
Browse files

tcp: Fix data-races around keepalive sysctl knobs. 



While reading sysctl_tcp_keepalive_(time|probes|intvl), they can be changed
concurrently.  Thus, we need to add READ_ONCE() to their readers.

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Signed-off-by: default avatarKuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 8ebcc62c

include/net/tcp.h

+6 −3
Original line number Diff line number Diff line
@@ -1493,21 +1493,24 @@ static inline int keepalive_intvl_when(const struct tcp_sock *tp) 
{

	struct net *net = sock_net((struct sock *)tp);



	return tp->keepalive_intvl ? : net->ipv4.sysctl_tcp_keepalive_intvl;

	return tp->keepalive_intvl ? :

		READ_ONCE(net->ipv4.sysctl_tcp_keepalive_intvl);

}



static inline int keepalive_time_when(const struct tcp_sock *tp)

{

	struct net *net = sock_net((struct sock *)tp);



	return tp->keepalive_time ? : net->ipv4.sysctl_tcp_keepalive_time;

	return tp->keepalive_time ? :

		READ_ONCE(net->ipv4.sysctl_tcp_keepalive_time);

}



static inline int keepalive_probes(const struct tcp_sock *tp)

{

	struct net *net = sock_net((struct sock *)tp);



	return tp->keepalive_probes ? : net->ipv4.sysctl_tcp_keepalive_probes;

	return tp->keepalive_probes ? :

		READ_ONCE(net->ipv4.sysctl_tcp_keepalive_probes);

}



static inline u32 keepalive_time_elapsed(const struct tcp_sock *tp)

net/smc/smc_llc.c

+1 −1
Original line number Diff line number Diff line
@@ -2122,7 +2122,7 @@ void smc_llc_lgr_init(struct smc_link_group *lgr, struct smc_sock *smc) 
	init_waitqueue_head(&lgr->llc_flow_waiter);

	init_waitqueue_head(&lgr->llc_msg_waiter);

	mutex_init(&lgr->llc_conf_mutex);

	lgr->llc_testlink_time = net->ipv4.sysctl_tcp_keepalive_time;

	lgr->llc_testlink_time = READ_ONCE(net->ipv4.sysctl_tcp_keepalive_time);

}



/* called after lgr was removed from lgr_list */