netdev - [PATCH net-next 12/14] ipv6: lockless IPV6_ROUTER_ALERT

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20230912160212.3467976-13-edumazet@google.com>
Date: Tue, 12 Sep 2023 16:02:10 +0000
From: Eric Dumazet <edumazet@...gle.com>
To: "David S . Miller" <davem@...emloft.net>, Jakub Kicinski <kuba@...nel.org>, 
	Paolo Abeni <pabeni@...hat.com>
Cc: David Ahern <dsahern@...nel.org>, netdev@...r.kernel.org, eric.dumazet@...il.com, 
	Eric Dumazet <edumazet@...gle.com>
Subject: [PATCH net-next 12/14] ipv6: lockless IPV6_ROUTER_ALERT_ISOLATE implementation

Reads from np->rtalert_isolate are racy.

Move this flag to inet->inet_flags to fix data-races.

Signed-off-by: Eric Dumazet <edumazet@...gle.com>
---
 include/linux/ipv6.h     |  3 +--
 include/net/inet_sock.h  |  1 +
 net/ipv6/ip6_output.c    |  3 +--
 net/ipv6/ipv6_sockglue.c | 13 ++++++-------
 4 files changed, 9 insertions(+), 11 deletions(-)

diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h
index e62413371ea40cbd9f13aa6ac6b6be41a6831237..f288a35f157f73ded445639c30f3365047fd9ddc 100644
--- a/include/linux/ipv6.h
+++ b/include/linux/ipv6.h
@@ -246,11 +246,10 @@ struct ipv6_pinfo {
 	__u16			sndflow:1,
 				pmtudisc:3,
 				padding:1,	/* 1 bit hole */
-				srcprefs:3,	/* 001: prefer temporary address
+				srcprefs:3;	/* 001: prefer temporary address
 						 * 010: prefer public address
 						 * 100: prefer care-of address
 						 */
-				rtalert_isolate:1;
 	__u8			min_hopcount;
 	__u8			tclass;
 	__be32			rcv_flowinfo;
diff --git a/include/net/inet_sock.h b/include/net/inet_sock.h
index 5d61c7dc6577827740254f0e9aa288065f1bda7f..befee0f66c0555f3ac4524fd8f7780ff21c04aaa 100644
--- a/include/net/inet_sock.h
+++ b/include/net/inet_sock.h
@@ -276,6 +276,7 @@ enum {
 	INET_FLAGS_DONTFRAG	= 25,
 	INET_FLAGS_RECVERR6	= 26,
 	INET_FLAGS_REPFLOW	= 27,
+	INET_FLAGS_RTALERT_ISOLATE = 28,
 };
 
 /* cmsg flags for inet */
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 8851fe5d45a0781c8b78c995c2c4c6c81e10cd52..f87d8491d7e273f167b7b144a7e134783e1b80f6 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -368,9 +368,8 @@ static int ip6_call_ra_chain(struct sk_buff *skb, int sel)
 		if (sk && ra->sel == sel &&
 		    (!sk->sk_bound_dev_if ||
 		     sk->sk_bound_dev_if == skb->dev->ifindex)) {
-			struct ipv6_pinfo *np = inet6_sk(sk);
 
-			if (np && np->rtalert_isolate &&
+			if (inet6_test_bit(RTALERT_ISOLATE, sk) &&
 			    !net_eq(sock_net(sk), dev_net(skb->dev))) {
 				continue;
 			}
diff --git a/net/ipv6/ipv6_sockglue.c b/net/ipv6/ipv6_sockglue.c
index ec10b45c49c15f9655466a529046f741f8b9fc69..c22a492e05360b68ef6868707e363f2ce84a4c35 100644
--- a/net/ipv6/ipv6_sockglue.c
+++ b/net/ipv6/ipv6_sockglue.c
@@ -488,6 +488,11 @@ int do_ipv6_setsockopt(struct sock *sk, int level, int optname,
 		if (!val)
 			skb_errqueue_purge(&sk->sk_error_queue);
 		return 0;
+	case IPV6_ROUTER_ALERT_ISOLATE:
+		if (optlen < sizeof(int))
+			return -EINVAL;
+		inet6_assign_bit(RTALERT_ISOLATE, sk, valbool);
+		return 0;
 	}
 	if (needs_rtnl)
 		rtnl_lock();
@@ -936,12 +941,6 @@ int do_ipv6_setsockopt(struct sock *sk, int level, int optname,
 			goto e_inval;
 		retv = ip6_ra_control(sk, val);
 		break;
-	case IPV6_ROUTER_ALERT_ISOLATE:
-		if (optlen < sizeof(int))
-			goto e_inval;
-		np->rtalert_isolate = valbool;
-		retv = 0;
-		break;
 	case IPV6_MTU_DISCOVER:
 		if (optlen < sizeof(int))
 			goto e_inval;
@@ -1452,7 +1451,7 @@ int do_ipv6_getsockopt(struct sock *sk, int level, int optname,
 		break;
 
 	case IPV6_ROUTER_ALERT_ISOLATE:
-		val = np->rtalert_isolate;
+		val = inet6_test_bit(RTALERT_ISOLATE, sk);
 		break;
 
 	case IPV6_RECVERR_RFC4884:
-- 
2.42.0.283.g2d96d420d3-goog