From: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
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@xxxxxxxxxx>
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Ziyang Xuan <william.xuanziyang@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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(-)
--- a/include/net/ipv6.h
+++ b/include/net/ipv6.h
@@ -1119,6 +1119,7 @@ void ipv6_local_error(struct sock *sk, i
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,
--- a/include/net/udp.h
+++ b/include/net/udp.h
@@ -270,7 +270,7 @@ static inline bool udp_sk_bound_dev_eq(s
}
/* 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);
--- a/include/net/udplite.h
+++ b/include/net/udplite.h
@@ -24,14 +24,6 @@ static __inline__ int udplite_getfrag(vo
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
*/
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -1596,7 +1596,7 @@ drop:
}
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);
@@ -1609,10 +1609,14 @@ 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)
{
@@ -1620,7 +1624,6 @@ 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)
{
--- a/net/ipv4/udplite.c
+++ b/net/ipv4/udplite.c
@@ -17,6 +17,14 @@
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);
--- a/net/ipv6/af_inet6.c
+++ b/net/ipv6/af_inet6.c
@@ -108,6 +108,12 @@ static __inline__ struct ipv6_pinfo *ine
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)
{
@@ -200,7 +206,7 @@ lookup_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;
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -55,6 +55,19 @@
#include <trace/events/skb.h>
#include "udp_impl.h"
+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,
@@ -1721,7 +1734,7 @@ 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,
--- a/net/ipv6/udp_impl.h
+++ b/net/ipv6/udp_impl.h
@@ -12,6 +12,7 @@ int __udp6_lib_rcv(struct sk_buff *, str
int __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);
void udp_v6_rehash(struct sock *sk);
--- a/net/ipv6/udplite.c
+++ b/net/ipv6/udplite.c
@@ -12,6 +12,13 @@
#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);
@@ -38,7 +45,7 @@ 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,
