[PATCH 4.9 28/63] SUNRPC: Fix a race with XPRT_CONNECTING

From: Greg Kroah-Hartman
Date: Fri Jan 11 2019 - 10:05:09 EST


4.9-stable review patch. If anyone has any objections, please let me know.

------------------

[ Upstream commit cf76785d30712d90185455e752337acdb53d2a5d ]

Ensure that we clear XPRT_CONNECTING before releasing the XPRT_LOCK so that
we don't have races between the (asynchronous) socket setup code and
tasks in xprt_connect().

Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
Tested-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
net/sunrpc/xprtsock.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index 1bf9153004cd..280fb3178708 100644
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -2209,8 +2209,8 @@ static void xs_udp_setup_socket(struct work_struct *work)
trace_rpc_socket_connect(xprt, sock, 0);
status = 0;
out:
- xprt_unlock_connect(xprt, transport);
xprt_clear_connecting(xprt);
+ xprt_unlock_connect(xprt, transport);
xprt_wake_pending_tasks(xprt, status);
}

@@ -2395,8 +2395,8 @@ static void xs_tcp_setup_socket(struct work_struct *work)
}
status = -EAGAIN;
out:
- xprt_unlock_connect(xprt, transport);
xprt_clear_connecting(xprt);
+ xprt_unlock_connect(xprt, transport);
xprt_wake_pending_tasks(xprt, status);
}

--
2.19.1