| From 20405d698a27bd1819ce95cc86e23726aa728510 Mon Sep 17 00:00:00 2001 |
| From: Sebastian Andrzej Siewior <bigeasy@linutronix.de> |
| Date: Wed, 31 Aug 2016 17:54:09 +0200 |
| Subject: [PATCH] net: add a lock around icmp_sk() |
| |
| It looks like the this_cpu_ptr() access in icmp_sk() is protected with |
| local_bh_disable(). To avoid missing serialization in -RT I am adding |
| here a local lock. No crash has been observed, this is just precaution. |
| |
| Cc: stable-rt@vger.kernel.org |
| Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> |
| |
| diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c |
| index 9144fa7df2ad..bfa889e804f1 100644 |
| --- a/net/ipv4/icmp.c |
| +++ b/net/ipv4/icmp.c |
| @@ -77,6 +77,7 @@ |
| #include <linux/string.h> |
| #include <linux/netfilter_ipv4.h> |
| #include <linux/slab.h> |
| +#include <linux/locallock.h> |
| #include <net/snmp.h> |
| #include <net/ip.h> |
| #include <net/route.h> |
| @@ -204,6 +205,8 @@ static const struct icmp_control icmp_pointers[NR_ICMP_TYPES+1]; |
| * |
| * On SMP we have one ICMP socket per-cpu. |
| */ |
| +static DEFINE_LOCAL_IRQ_LOCK(icmp_sk_lock); |
| + |
| static struct sock *icmp_sk(struct net *net) |
| { |
| return *this_cpu_ptr(net->ipv4.icmp_sk); |
| @@ -417,6 +420,7 @@ static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb) |
| |
| /* Needed by both icmp_global_allow and icmp_xmit_lock */ |
| local_bh_disable(); |
| + local_lock(icmp_sk_lock); |
| |
| /* global icmp_msgs_per_sec */ |
| if (!icmpv4_global_allow(net, type, code)) |
| @@ -461,6 +465,7 @@ static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb) |
| out_unlock: |
| icmp_xmit_unlock(sk); |
| out_bh_enable: |
| + local_unlock(icmp_sk_lock); |
| local_bh_enable(); |
| } |
| |
| @@ -656,6 +661,7 @@ void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info) |
| |
| /* Needed by both icmp_global_allow and icmp_xmit_lock */ |
| local_bh_disable(); |
| + local_lock(icmp_sk_lock); |
| |
| /* Check global sysctl_icmp_msgs_per_sec ratelimit, unless |
| * incoming dev is loopback. If outgoing dev change to not be |
| @@ -744,6 +750,7 @@ void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info) |
| out_unlock: |
| icmp_xmit_unlock(sk); |
| out_bh_enable: |
| + local_unlock(icmp_sk_lock); |
| local_bh_enable(); |
| out:; |
| } |
| -- |
| 2.1.4 |
| |