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authorKuniyuki Iwashima <kuniyu@amazon.com>2022-10-06 21:53:46 +0300
committerJakub Kicinski <kuba@kernel.org>2022-10-13 03:50:37 +0300
commit21985f43376cee092702d6cb963ff97a9d2ede68 (patch)
tree0084a093718e00e822b53495b5f506a2aee4ea15
parent3c52c6bb831f6335c176a0fc7214e26f43adbd11 (diff)
downloadlinux-21985f43376cee092702d6cb963ff97a9d2ede68.tar.xz
udp: Call inet6_destroy_sock() in setsockopt(IPV6_ADDRFORM).
Commit 4b340ae20d0e ("IPv6: Complete IPV6_DONTFRAG support") forgot to add a change to free inet6_sk(sk)->rxpmtu while converting an IPv6 socket into IPv4 with IPV6_ADDRFORM. After conversion, sk_prot is changed to udp_prot and ->destroy() never cleans it up, resulting in a memory leak. This is due to the discrepancy between inet6_destroy_sock() and IPV6_ADDRFORM, so let's call inet6_destroy_sock() from IPV6_ADDRFORM to remove the difference. However, this is not enough for now because rxpmtu can be changed without lock_sock() after commit 03485f2adcde ("udpv6: Add lockless sendmsg() support"). We will fix this case in the following patch. Note we will rename inet6_destroy_sock() to inet6_cleanup_sock() and remove unnecessary inet6_destroy_sock() calls in sk_prot->destroy() in the future. Fixes: 4b340ae20d0e ("IPv6: Complete IPV6_DONTFRAG support") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
-rw-r--r--include/net/ipv6.h1
-rw-r--r--net/ipv6/af_inet6.c6
-rw-r--r--net/ipv6/ipv6_sockglue.c20
3 files changed, 15 insertions, 12 deletions
diff --git a/include/net/ipv6.h b/include/net/ipv6.h
index d664ba5812d8..335a49ecd8a0 100644
--- a/include/net/ipv6.h
+++ b/include/net/ipv6.h
@@ -1182,6 +1182,7 @@ void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port,
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);
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/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c
index d40b7d60e00e..ded827944fa6 100644
--- a/net/ipv6/af_inet6.c
+++ b/net/ipv6/af_inet6.c
@@ -510,6 +510,12 @@ void inet6_destroy_sock(struct sock *sk)
}
EXPORT_SYMBOL_GPL(inet6_destroy_sock);
+void inet6_cleanup_sock(struct sock *sk)
+{
+ inet6_destroy_sock(sk);
+}
+EXPORT_SYMBOL_GPL(inet6_cleanup_sock);
+
/*
* This does both peername and sockname.
*/
diff --git a/net/ipv6/ipv6_sockglue.c b/net/ipv6/ipv6_sockglue.c
index 408345fc4c5c..a20edae868fd 100644
--- a/net/ipv6/ipv6_sockglue.c
+++ b/net/ipv6/ipv6_sockglue.c
@@ -431,9 +431,6 @@ int do_ipv6_setsockopt(struct sock *sk, int level, int optname,
if (optlen < sizeof(int))
goto e_inval;
if (val == PF_INET) {
- struct ipv6_txoptions *opt;
- struct sk_buff *pktopt;
-
if (sk->sk_type == SOCK_RAW)
break;
@@ -464,7 +461,6 @@ int do_ipv6_setsockopt(struct sock *sk, int level, int optname,
break;
}
- fl6_free_socklist(sk);
__ipv6_sock_mc_close(sk);
__ipv6_sock_ac_close(sk);
@@ -501,14 +497,14 @@ int do_ipv6_setsockopt(struct sock *sk, int level, int optname,
sk->sk_socket->ops = &inet_dgram_ops;
sk->sk_family = PF_INET;
}
- opt = xchg((__force struct ipv6_txoptions **)&np->opt,
- NULL);
- if (opt) {
- atomic_sub(opt->tot_len, &sk->sk_omem_alloc);
- txopt_put(opt);
- }
- pktopt = xchg(&np->pktoptions, NULL);
- kfree_skb(pktopt);
+
+ /* Disable all options not to allocate memory anymore,
+ * but there is still a race. See the lockless path
+ * in udpv6_sendmsg() and ipv6_local_rxpmtu().
+ */
+ np->rxopt.all = 0;
+
+ inet6_cleanup_sock(sk);
/*
* ... and add it to the refcnt debug socks count