[PATCH 5.4 51/67] ipv6: fix memory leaks on IPV6_ADDRFORM path

Greg Kroah-Hartman
2020-08-10T15:28:15Z

From: Cong Wang <xiyou.wangcong@gmail.com>

[ Upstream commit 8c0de6e96c9794cb523a516c465991a70245da1c ]

IPV6_ADDRFORM causes resource leaks when converting an IPv6 socket
to IPv4, particularly struct ipv6_ac_socklist. Similar to
struct ipv6_mc_socklist, we should just close it on this path.

This bug can be easily reproduced with the following C program:

#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>

int main()
{
int s, value;
struct sockaddr_in6 addr;
struct ipv6_mreq m6;

s = socket(AF_INET6, SOCK_DGRAM, 0);
addr.sin6_family = AF_INET6;
addr.sin6_port = htons(5000);
inet_pton(AF_INET6, "::ffff:192.168.122.194", &addr.sin6_addr);
connect(s, (struct sockaddr *)&addr, sizeof(addr));

inet_pton(AF_INET6, "fe80::AAAA", &m6.ipv6mr_multiaddr);
m6.ipv6mr_interface = 5;
setsockopt(s, SOL_IPV6, IPV6_JOIN_ANYCAST, &m6, sizeof(m6));

value = AF_INET;
setsockopt(s, SOL_IPV6, IPV6_ADDRFORM, &value, sizeof(value));

close(s);
return 0;
}

Reported-by: ch3332xr@gmail.com
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
include/net/addrconf.h | 1 +
net/ipv6/anycast.c | 17 ++++++++++++-----
net/ipv6/ipv6_sockglue.c | 1 +
3 files changed, 14 insertions(+), 5 deletions(-)

--- a/include/net/addrconf.h
+++ b/include/net/addrconf.h
@@ -273,6 +273,7 @@ int ipv6_sock_ac_join(struct sock *sk, i
const struct in6_addr *addr);
int ipv6_sock_ac_drop(struct sock *sk, int ifindex,
const struct in6_addr *addr);
+void __ipv6_sock_ac_close(struct sock *sk);
void ipv6_sock_ac_close(struct sock *sk);

int __ipv6_dev_ac_inc(struct inet6_dev *idev, const struct in6_addr *addr);
--- a/net/ipv6/anycast.c
+++ b/net/ipv6/anycast.c
@@ -183,7 +183,7 @@ int ipv6_sock_ac_drop(struct sock *sk, i
return 0;
}

-void ipv6_sock_ac_close(struct sock *sk)
+void __ipv6_sock_ac_close(struct sock *sk)
{
struct ipv6_pinfo *np = inet6_sk(sk);
struct net_device *dev = NULL;
@@ -191,10 +191,7 @@ void ipv6_sock_ac_close(struct sock *sk)
struct net *net = sock_net(sk);
int prev_index;

- if (!np->ipv6_ac_list)
- return;
-
- rtnl_lock();
+ ASSERT_RTNL();
pac = np->ipv6_ac_list;
np->ipv6_ac_list = NULL;

@@ -211,6 +208,16 @@ void ipv6_sock_ac_close(struct sock *sk)
sock_kfree_s(sk, pac, sizeof(*pac));
pac = next;
}
+}
+
+void ipv6_sock_ac_close(struct sock *sk)
+{
+ struct ipv6_pinfo *np = inet6_sk(sk);
+
+ if (!np->ipv6_ac_list)
+ return;
+ rtnl_lock();
+ __ipv6_sock_ac_close(sk);
rtnl_unlock();
}

--- a/net/ipv6/ipv6_sockglue.c
+++ b/net/ipv6/ipv6_sockglue.c
@@ -205,6 +205,7 @@ static int do_ipv6_setsockopt(struct soc

fl6_free_socklist(sk);
__ipv6_sock_mc_close(sk);
+ __ipv6_sock_ac_close(sk);

/*
* Sock is moving from IPv6 to IPv4 (sk_prot), so