[IPV6]: Ensure to use icmpv6_socket in non-preemptive context.
We saw following trace several times:
|BUG: using smp_processor_id() in preemptible [00000001] code: httpd/30137
|caller is icmpv6_send+0x23/0x540
| [<c01ad63b>] smp_processor_id+0x9b/0xb8
| [<c02993e7>] icmpv6_send+0x23/0x540
This is because of icmpv6_socket, which is the only one user of
smp_processor_id() in icmpv6_send(), AFAIK.
Since it should be used in non-preemptive context,
let's defer the dereference after disabling preemption
(by icmpv6_xmit_lock()).
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c
index 8e0f569..ff3ec98 100644
--- a/net/ipv6/icmp.c
+++ b/net/ipv6/icmp.c
@@ -277,8 +277,8 @@
{
struct inet6_dev *idev = NULL;
struct ipv6hdr *hdr = skb->nh.ipv6h;
- struct sock *sk = icmpv6_socket->sk;
- struct ipv6_pinfo *np = inet6_sk(sk);
+ struct sock *sk;
+ struct ipv6_pinfo *np;
struct in6_addr *saddr = NULL;
struct dst_entry *dst;
struct icmp6hdr tmp_hdr;
@@ -358,6 +358,9 @@
if (icmpv6_xmit_lock())
return;
+ sk = icmpv6_socket->sk;
+ np = inet6_sk(sk);
+
if (!icmpv6_xrlim_allow(sk, type, &fl))
goto out;
@@ -423,9 +426,9 @@
static void icmpv6_echo_reply(struct sk_buff *skb)
{
- struct sock *sk = icmpv6_socket->sk;
+ struct sock *sk;
struct inet6_dev *idev;
- struct ipv6_pinfo *np = inet6_sk(sk);
+ struct ipv6_pinfo *np;
struct in6_addr *saddr = NULL;
struct icmp6hdr *icmph = (struct icmp6hdr *) skb->h.raw;
struct icmp6hdr tmp_hdr;
@@ -454,6 +457,9 @@
if (icmpv6_xmit_lock())
return;
+ sk = icmpv6_socket->sk;
+ np = inet6_sk(sk);
+
if (!fl.oif && ipv6_addr_is_multicast(&fl.fl6_dst))
fl.oif = np->mcast_oif;