Commit 66484bb9 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_broadcasts. 



While reading sysctl_icmp_echo_ignore_broadcasts, 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 4a2f7083

net/ipv4/icmp.c

+1 −1
Original line number Diff line number Diff line
@@ -1249,7 +1249,7 @@ int icmp_rcv(struct sk_buff *skb) 
		 */

		if ((icmph->type == ICMP_ECHO ||

		     icmph->type == ICMP_TIMESTAMP) &&

		    net->ipv4.sysctl_icmp_echo_ignore_broadcasts) {

		    READ_ONCE(net->ipv4.sysctl_icmp_echo_ignore_broadcasts)) {

			reason = SKB_DROP_REASON_INVALID_PROTO;

			goto error;

		}

net/ipv4/sysctl_net_ipv4.c

+2 −0
Original line number Diff line number Diff line
@@ -617,6 +617,8 @@ 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_ignore_bogus_error_responses",