[PATCH 5.11 157/210] mptcp: revert "mptcp: provide subflow aware release function"

Greg Kroah-Hartman
2021-04-12T09:43:32Z

From: Paolo Abeni <pabeni@redhat.com>

[ Upstream commit 0a3cc57978d1d1448312f8973bd84dca4a71433a ]

This change reverts commit ad98dd37051e ("mptcp: provide subflow aware
release function"). The latter introduced a deadlock spotted by
syzkaller and is not needed anymore after the previous commit.

Fixes: ad98dd37051e ("mptcp: provide subflow aware release function")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/mptcp/protocol.c | 55 ++------------------------------------------
1 file changed, 2 insertions(+), 53 deletions(-)

diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index de9f2509acbe..e337b35a368f 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -11,7 +11,6 @@
#include <linux/netdevice.h>
#include <linux/sched/signal.h>
#include <linux/atomic.h>
-#include <linux/igmp.h>
#include <net/sock.h>
#include <net/inet_common.h>
#include <net/inet_hashtables.h>
@@ -20,7 +19,6 @@
#include <net/tcp_states.h>
#if IS_ENABLED(CONFIG_MPTCP_IPV6)
#include <net/transp_v6.h>
-#include <net/addrconf.h>
#endif
#include <net/mptcp.h>
#include <net/xfrm.h>
@@ -3424,34 +3422,10 @@ static __poll_t mptcp_poll(struct file *file, struct socket *sock,
return mask;
}

-static int mptcp_release(struct socket *sock)
-{
- struct mptcp_subflow_context *subflow;
- struct sock *sk = sock->sk;
- struct mptcp_sock *msk;
-
- if (!sk)
- return 0;
-
- lock_sock(sk);
-
- msk = mptcp_sk(sk);
-
- mptcp_for_each_subflow(msk, subflow) {
- struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
-
- ip_mc_drop_socket(ssk);
- }
-
- release_sock(sk);
-
- return inet_release(sock);
-}
-
static const struct proto_ops mptcp_stream_ops = {
.family = PF_INET,
.owner = THIS_MODULE,
- .release = mptcp_release,
+ .release = inet_release,
.bind = mptcp_bind,
.connect = mptcp_stream_connect,
.socketpair = sock_no_socketpair,
@@ -3498,35 +3472,10 @@ void __init mptcp_proto_init(void)
}

#if IS_ENABLED(CONFIG_MPTCP_IPV6)
-static int mptcp6_release(struct socket *sock)
-{
- struct mptcp_subflow_context *subflow;
- struct mptcp_sock *msk;
- struct sock *sk = sock->sk;
-
- if (!sk)
- return 0;
-
- lock_sock(sk);
-
- msk = mptcp_sk(sk);
-
- mptcp_for_each_subflow(msk, subflow) {
- struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
-
- ip_mc_drop_socket(ssk);
- ipv6_sock_mc_close(ssk);
- ipv6_sock_ac_close(ssk);
- }
-
- release_sock(sk);
- return inet6_release(sock);
-}
-
static const struct proto_ops mptcp_v6_stream_ops = {
.family = PF_INET6,
.owner = THIS_MODULE,
- .release = mptcp6_release,
+ .release = inet6_release,
.bind = mptcp_bind,
.connect = mptcp_stream_connect,
.socketpair = sock_no_socketpair,
--
2.30.2