Commit bb7bb35a authored by Kuniyuki Iwashima's avatar Kuniyuki Iwashima Committed by David S. Miller
Browse files

icmp: Fix a data-race around sysctl_icmp_echo_ignore_all. 



While reading sysctl_icmp_echo_ignore_all, it can be changed concurrently.
Thus, we need to add READ_ONCE() to its reader.

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 6f605b57

net/ipv4/icmp.c

+1 −1
Original line number Diff line number Diff line
@@ -993,7 +993,7 @@ static enum skb_drop_reason icmp_echo(struct sk_buff *skb) 


	net = dev_net(skb_dst(skb)->dev);

	/* should there be an ICMP stat for ignored echos? */

	if (net->ipv4.sysctl_icmp_echo_ignore_all)

	if (READ_ONCE(net->ipv4.sysctl_icmp_echo_ignore_all))

		return SKB_NOT_DROPPED_YET;



	icmp_param.data.icmph	   = *icmp_hdr(skb);

net/ipv4/sysctl_net_ipv4.c

+2 −0
Original line number Diff line number Diff line
@@ -599,6 +599,8 @@ static struct ctl_table ipv4_net_table[] = { 
		.maxlen		= sizeof(u8),

		.mode		= 0644,

		.proc_handler	= proc_dou8vec_minmax,

		.extra1		= SYSCTL_ZERO,

		.extra2		= SYSCTL_ONE

	},

	{

		.procname	= "icmp_echo_enable_probe",