diff mbox series

[4.19,2/5] tcp/udp: Call inet6_destroy_sock() in IPv6 sk->sk_destruct().

Message ID ab8157eb3e3808bdabcc62bf2e239c1b0e600b26.1681893438.git.william.xuanziyang@huawei.com (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series inet6: Backport complete patchset for inet6_destroy_sock() call modification | expand

Checks

Context Check Description
netdev/tree_selection success Guessing tree name failed - patch did not apply

Commit Message

Ziyang Xuan (William) April 20, 2023, 3:12 a.m. UTC 
From: Kuniyuki Iwashima <kuniyu@amazon.com>

commit d38afeec26ed4739c640bf286c270559aab2ba5f upstream.

Originally, inet6_sk(sk)->XXX were changed under lock_sock(), so we were
able to clean them up by calling inet6_destroy_sock() during the IPv6 ->
IPv4 conversion by IPV6_ADDRFORM.  However, commit 03485f2adcde ("udpv6:
Add lockless sendmsg() support") added a lockless memory allocation path,
which could cause a memory leak:

setsockopt(IPV6_ADDRFORM)                 sendmsg()
+-----------------------+                 +-------+
- do_ipv6_setsockopt(sk, ...)             - udpv6_sendmsg(sk, ...)
  - sockopt_lock_sock(sk)                   ^._ called via udpv6_prot
    - lock_sock(sk)                             before WRITE_ONCE()
  - WRITE_ONCE(sk->sk_prot, &tcp_prot)
  - inet6_destroy_sock()                    - if (!corkreq)
  - sockopt_release_sock(sk)                  - ip6_make_skb(sk, ...)
    - release_sock(sk)                          ^._ lockless fast path for
                                                    the non-corking case

                                                - __ip6_append_data(sk, ...)
                                                  - ipv6_local_rxpmtu(sk, ...)
                                                    - xchg(&np->rxpmtu, skb)
                                                      ^._ rxpmtu is never freed.

                                                - goto out_no_dst;

                                            - lock_sock(sk)

For now, rxpmtu is only the case, but not to miss the future change
and a similar bug fixed in commit e27326009a3d ("net: ping6: Fix
memleak in ipv6_renew_options()."), let's set a new function to IPv6
sk->sk_destruct() and call inet6_cleanup_sock() there.  Since the
conversion does not change sk->sk_destruct(), we can guarantee that
we can clean up IPv6 resources finally.

We can now remove all inet6_destroy_sock() calls from IPv6 protocol
specific ->destroy() functions, but such changes are invasive to
backport.  So they can be posted as a follow-up later for net-next.

Fixes: 03485f2adcde ("udpv6: Add lockless sendmsg() support")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com>
---
 include/net/ipv6.h    |  1 +
 include/net/udp.h     |  2 +-
 include/net/udplite.h |  8 --------
 net/ipv4/udp.c        |  9 ++++++---
 net/ipv4/udplite.c    |  8 ++++++++
 net/ipv6/af_inet6.c   |  8 +++++++-
 net/ipv6/udp.c        | 15 ++++++++++++++-
 net/ipv6/udp_impl.h   |  1 +
 net/ipv6/udplite.c    |  9 ++++++++-
 9 files changed, 46 insertions(+), 15 deletions(-)
diff mbox series

Patch

diff --git a/include/net/ipv6.h b/include/net/ipv6.h
index f33be9653aaa..0c883249814c 100644
--- a/include/net/ipv6.h
+++ b/include/net/ipv6.h
@@ -1041,6 +1041,7 @@  void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info);
 void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu);
 
 void inet6_cleanup_sock(struct sock *sk);
+void inet6_sock_destruct(struct sock *sk);
 int inet6_release(struct socket *sock);
 int inet6_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len);
 int inet6_getname(struct socket *sock, struct sockaddr *uaddr,
diff --git a/include/net/udp.h b/include/net/udp.h
index 618c83bea50d..48d881224524 100644
--- a/include/net/udp.h
+++ b/include/net/udp.h
@@ -254,7 +254,7 @@  static inline int udp_rqueue_get(struct sock *sk)
 }
 
 /* net/ipv4/udp.c */
-void udp_destruct_sock(struct sock *sk);
+void udp_destruct_common(struct sock *sk);
 void skb_consume_udp(struct sock *sk, struct sk_buff *skb, int len);
 int __udp_enqueue_schedule_skb(struct sock *sk, struct sk_buff *skb);
 void udp_skb_destructor(struct sock *sk, struct sk_buff *skb);
diff --git a/include/net/udplite.h b/include/net/udplite.h
index 9185e45b997f..c59ba86668af 100644
--- a/include/net/udplite.h
+++ b/include/net/udplite.h
@@ -24,14 +24,6 @@  static __inline__ int udplite_getfrag(void *from, char *to, int  offset,
 	return copy_from_iter_full(to, len, &msg->msg_iter) ? 0 : -EFAULT;
 }
 
-/* Designate sk as UDP-Lite socket */
-static inline int udplite_sk_init(struct sock *sk)
-{
-	udp_init_sock(sk);
-	udp_sk(sk)->pcflag = UDPLITE_BIT;
-	return 0;
-}
-
 /*
  * 	Checksumming routines
  */
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index dd3fa0ff84e7..a6048cc7fc35 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -1458,7 +1458,7 @@  int __udp_enqueue_schedule_skb(struct sock *sk, struct sk_buff *skb)
 }
 EXPORT_SYMBOL_GPL(__udp_enqueue_schedule_skb);
 
-void udp_destruct_sock(struct sock *sk)
+void udp_destruct_common(struct sock *sk)
 {
 	/* reclaim completely the forward allocated memory */
 	struct udp_sock *up = udp_sk(sk);
@@ -1471,10 +1471,14 @@  void udp_destruct_sock(struct sock *sk)
 		kfree_skb(skb);
 	}
 	udp_rmem_release(sk, total, 0, true);
+}
+EXPORT_SYMBOL_GPL(udp_destruct_common);
 
+static void udp_destruct_sock(struct sock *sk)
+{
+	udp_destruct_common(sk);
 	inet_sock_destruct(sk);
 }
-EXPORT_SYMBOL_GPL(udp_destruct_sock);
 
 int udp_init_sock(struct sock *sk)
 {
@@ -1482,7 +1486,6 @@  int udp_init_sock(struct sock *sk)
 	sk->sk_destruct = udp_destruct_sock;
 	return 0;
 }
-EXPORT_SYMBOL_GPL(udp_init_sock);
 
 void skb_consume_udp(struct sock *sk, struct sk_buff *skb, int len)
 {
diff --git a/net/ipv4/udplite.c b/net/ipv4/udplite.c
index 8545457752fb..6beab353bc8b 100644
--- a/net/ipv4/udplite.c
+++ b/net/ipv4/udplite.c
@@ -20,6 +20,14 @@ 
 struct udp_table 	udplite_table __read_mostly;
 EXPORT_SYMBOL(udplite_table);
 
+/* Designate sk as UDP-Lite socket */
+static int udplite_sk_init(struct sock *sk)
+{
+	udp_init_sock(sk);
+	udp_sk(sk)->pcflag = UDPLITE_BIT;
+	return 0;
+}
+
 static int udplite_rcv(struct sk_buff *skb)
 {
 	return __udp4_lib_rcv(skb, &udplite_table, IPPROTO_UDPLITE);
diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c
index b46fc19aed4a..5a07d9b7b086 100644
--- a/net/ipv6/af_inet6.c
+++ b/net/ipv6/af_inet6.c
@@ -107,6 +107,12 @@  static __inline__ struct ipv6_pinfo *inet6_sk_generic(struct sock *sk)
 	return (struct ipv6_pinfo *)(((u8 *)sk) + offset);
 }
 
+void inet6_sock_destruct(struct sock *sk)
+{
+	inet6_cleanup_sock(sk);
+	inet_sock_destruct(sk);
+}
+
 static int inet6_create(struct net *net, struct socket *sock, int protocol,
 			int kern)
 {
@@ -199,7 +205,7 @@  static int inet6_create(struct net *net, struct socket *sock, int protocol,
 			inet->hdrincl = 1;
 	}
 
-	sk->sk_destruct		= inet_sock_destruct;
+	sk->sk_destruct		= inet6_sock_destruct;
 	sk->sk_family		= PF_INET6;
 	sk->sk_protocol		= protocol;
 
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index 9b0cae403027..93c105d0a0c9 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -66,6 +66,19 @@  static bool udp6_lib_exact_dif_match(struct net *net, struct sk_buff *skb)
 	return false;
 }
 
+static void udpv6_destruct_sock(struct sock *sk)
+{
+	udp_destruct_common(sk);
+	inet6_sock_destruct(sk);
+}
+
+int udpv6_init_sock(struct sock *sk)
+{
+	skb_queue_head_init(&udp_sk(sk)->reader_queue);
+	sk->sk_destruct = udpv6_destruct_sock;
+	return 0;
+}
+
 static u32 udp6_ehashfn(const struct net *net,
 			const struct in6_addr *laddr,
 			const u16 lport,
@@ -1593,7 +1606,7 @@  struct proto udpv6_prot = {
 	.connect		= ip6_datagram_connect,
 	.disconnect		= udp_disconnect,
 	.ioctl			= udp_ioctl,
-	.init			= udp_init_sock,
+	.init			= udpv6_init_sock,
 	.destroy		= udpv6_destroy_sock,
 	.setsockopt		= udpv6_setsockopt,
 	.getsockopt		= udpv6_getsockopt,
diff --git a/net/ipv6/udp_impl.h b/net/ipv6/udp_impl.h
index 7903e21c178b..e5d067b09ccf 100644
--- a/net/ipv6/udp_impl.h
+++ b/net/ipv6/udp_impl.h
@@ -12,6 +12,7 @@  int __udp6_lib_rcv(struct sk_buff *, struct udp_table *, int);
 void __udp6_lib_err(struct sk_buff *, struct inet6_skb_parm *, u8, u8, int,
 		    __be32, struct udp_table *);
 
+int udpv6_init_sock(struct sock *sk);
 int udp_v6_get_port(struct sock *sk, unsigned short snum);
 
 int udpv6_getsockopt(struct sock *sk, int level, int optname,
diff --git a/net/ipv6/udplite.c b/net/ipv6/udplite.c
index 5000ad6878e6..f15b8305d87b 100644
--- a/net/ipv6/udplite.c
+++ b/net/ipv6/udplite.c
@@ -15,6 +15,13 @@ 
 #include <linux/proc_fs.h>
 #include "udp_impl.h"
 
+static int udplitev6_sk_init(struct sock *sk)
+{
+	udpv6_init_sock(sk);
+	udp_sk(sk)->pcflag = UDPLITE_BIT;
+	return 0;
+}
+
 static int udplitev6_rcv(struct sk_buff *skb)
 {
 	return __udp6_lib_rcv(skb, &udplite_table, IPPROTO_UDPLITE);
@@ -40,7 +47,7 @@  struct proto udplitev6_prot = {
 	.connect	   = ip6_datagram_connect,
 	.disconnect	   = udp_disconnect,
 	.ioctl		   = udp_ioctl,
-	.init		   = udplite_sk_init,
+	.init		   = udplitev6_sk_init,
 	.destroy	   = udpv6_destroy_sock,
 	.setsockopt	   = udpv6_setsockopt,
 	.getsockopt	   = udpv6_getsockopt,