net: ping: do not abuse udp_poll()

commit 77d4b1d3 upstream.

Alexander reported various KASAN messages triggered in recent kernels

The problem is that ping sockets should not use udp_poll() in the first
place, and recent changes in UDP stack finally exposed this old bug.

Fixes: c319b4d7 ("net: ipv4: add IPPROTO_ICMP socket kind")
Fixes: 6d0bfe22 ("net: ipv6: Add IPv6 support to the ping socket.")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Sasha Levin <alexander.levin@verizon.com>
Cc: Solar Designer <solar@openwall.com>
Cc: Vasiliy Kulikov <segoon@openwall.com>
Cc: Lorenzo Colitti <lorenzo@google.com>
Acked-By: Lorenzo Colitti <lorenzo@google.com>
Tested-By: Lorenzo Colitti <lorenzo@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

include/net/ipv6.h

@@ -851,6 +851,7 @@ int inet6_hash_connect(struct inet_timewait_death_row *death_row,
  */
 extern const struct proto_ops inet6_stream_ops;
 extern const struct proto_ops inet6_dgram_ops;
+extern const struct proto_ops inet6_sockraw_ops;
 
 struct group_source_req;
 struct group_filter;

net/ipv4/af_inet.c

@@ -1020,7 +1020,7 @@ static struct inet_protosw inetsw_array[] =
 		.type =       SOCK_DGRAM,
 		.protocol =   IPPROTO_ICMP,
 		.prot =       &ping_prot,
-		.ops =        &inet_dgram_ops,
+		.ops =        &inet_sockraw_ops,
 		.flags =      INET_PROTOSW_REUSE,
        },
 

net/ipv6/ping.c

@@ -50,7 +50,7 @@ static struct inet_protosw pingv6_protosw = {
 	.type =      SOCK_DGRAM,
 	.protocol =  IPPROTO_ICMPV6,
 	.prot =      &pingv6_prot,
-	.ops =       &inet6_dgram_ops,
+	.ops =       &inet6_sockraw_ops,
 	.flags =     INET_PROTOSW_REUSE,
 };
 

net/ipv6/raw.c

@@ -1299,7 +1299,7 @@ void raw6_proc_exit(void)
 #endif	/* CONFIG_PROC_FS */
 
 /* Same as inet6_dgram_ops, sans udp_poll.  */
-static const struct proto_ops inet6_sockraw_ops = {
+const struct proto_ops inet6_sockraw_ops = {
 	.family		   = PF_INET6,
 	.owner		   = THIS_MODULE,
 	.release	   = inet6_release,