[ICMP]: Add return code to icmp_init.

icmp_init could fail and this is normal for namespace other than initial.
So, the panic should be triggered only on init_net initialization path.

Additionally create rollback path for icmp_init as a separate function.
It will also be used later during namespace destruction.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Acked-by: Daniel Lezcano <dlezcano@fr.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 24 insertions, 5 deletions

diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index a7a99ac856dc..4f539bd48718 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -1430,7 +1430,8 @@ static int __init inet_init(void)
          *      Set the ICMP layer up
          */
 
-        icmp_init();
+        if (icmp_init() < 0)
+                panic("Failed to create the ICMP control socket.\n");
 
         /*
          *      Initialise the multicast router
diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index 98372db66c66..b345b3d9bcaa 100644
--- a/net/ipv4/icmp.c
+++ b/net/ipv4/icmp.c
@@ -1139,19 +1139,32 @@ static const struct icmp_control icmp_pointers[NR_ICMP_TYPES + 1] = {
         },
 };
 
-void __init icmp_init(void)
+static void __exit icmp_exit(void)
 {
-        struct inet_sock *inet;
         int i;
 
         for_each_possible_cpu(i) {
-                int err;
+                struct socket *sock;
+
+                sock = per_cpu(__icmp_socket, i);
+                if (sock == NULL)
+                        continue;
+                per_cpu(__icmp_socket, i) = NULL;
+                sock_release(sock);
+        }
+}
 
+int __init icmp_init(void)
+{
+        struct inet_sock *inet;
+        int i, err;
+
+        for_each_possible_cpu(i) {
                 err = sock_create_kern(PF_INET, SOCK_RAW, IPPROTO_ICMP,
                                        &per_cpu(__icmp_socket, i));
 
                 if (err < 0)
-                        panic("Failed to create the ICMP control socket.\n");
+                        goto fail;
 
                 per_cpu(__icmp_socket, i)->sk->sk_allocation = GFP_ATOMIC;
 
@@ -1171,6 +1184,11 @@ void __init icmp_init(void)
                  */
                 per_cpu(__icmp_socket, i)->sk->sk_prot->unhash(per_cpu(__icmp_socket, i)->sk);
         }
+        return 0;
+
+fail:
+        icmp_exit();
+        return err;
 }
 
 EXPORT_SYMBOL(icmp_err_convert);