From 975a0f14d5cd29fe4b33190b5afcfa9f244b769d Mon Sep 17 00:00:00 2001 From: Meena Shanmugam Date: Wed, 18 May 2022 18:40:10 +0000 Subject: [PATCH] SUNRPC: Don't call connect() more than once on a TCP socket From: Trond Myklebust commit 89f42494f92f448747bd8a7ab1ae8b5d5520577d upstream. Avoid socket state races due to repeated calls to ->connect() using the same socket. If connect() returns 0 due to the connection having completed, but we are in fact in a closing state, then we may leave the XPRT_CONNECTING flag set on the transport. Reported-by: Enrico Scholz Fixes: 3be232f11a3c ("SUNRPC: Prevent immediate close+reconnect") Signed-off-by: Trond Myklebust [meenashanmugam: Fix merge conflict in xs_tcp_setup_socket] Signed-off-by: Meena Shanmugam Signed-off-by: Greg Kroah-Hartman --- include/linux/sunrpc/xprtsock.h | 1 + net/sunrpc/xprtsock.c | 22 ++++++++++++---------- 2 files changed, 13 insertions(+), 10 deletions(-) diff --git a/include/linux/sunrpc/xprtsock.h b/include/linux/sunrpc/xprtsock.h index a940de03808d..46deca97e806 100644 --- a/include/linux/sunrpc/xprtsock.h +++ b/include/linux/sunrpc/xprtsock.h @@ -90,6 +90,7 @@ struct sock_xprt { #define XPRT_SOCK_WAKE_WRITE (5) #define XPRT_SOCK_WAKE_PENDING (6) #define XPRT_SOCK_WAKE_DISCONNECT (7) +#define XPRT_SOCK_CONNECT_SENT (8) #endif /* __KERNEL__ */ diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c index 49ba817f4fb6..29e9c54a89d3 100644 --- a/net/sunrpc/xprtsock.c +++ b/net/sunrpc/xprtsock.c @@ -2384,10 +2384,14 @@ static void xs_tcp_setup_socket(struct work_struct *work) struct rpc_xprt *xprt = &transport->xprt; int status = -EIO; - if (!sock) { - sock = xs_create_sock(xprt, transport, - xs_addr(xprt)->sa_family, SOCK_STREAM, - IPPROTO_TCP, true); + if (xprt_connected(xprt)) + goto out; + if (test_and_clear_bit(XPRT_SOCK_CONNECT_SENT, + &transport->sock_state) || + !sock) { + xs_reset_transport(transport); + sock = xs_create_sock(xprt, transport, xs_addr(xprt)->sa_family, + SOCK_STREAM, IPPROTO_TCP, true); if (IS_ERR(sock)) { status = PTR_ERR(sock); goto out; @@ -2418,6 +2422,8 @@ static void xs_tcp_setup_socket(struct work_struct *work) break; case 0: case -EINPROGRESS: + set_bit(XPRT_SOCK_CONNECT_SENT, &transport->sock_state); + fallthrough; case -EALREADY: xprt_unlock_connect(xprt, transport); return; @@ -2469,13 +2475,9 @@ static void xs_connect(struct rpc_xprt *xprt, struct rpc_task *task) WARN_ON_ONCE(!xprt_lock_connect(xprt, task, transport)); - if (transport->sock != NULL && !xprt_connecting(xprt)) { + if (transport->sock != NULL) { dprintk("RPC: xs_connect delayed xprt %p for %lu " - "seconds\n", - xprt, xprt->reestablish_timeout / HZ); - - /* Start by resetting any existing state */ - xs_reset_transport(transport); + "seconds\n", xprt, xprt->reestablish_timeout / HZ); delay = xprt_reconnect_delay(xprt); xprt_reconnect_backoff(xprt, XS_TCP_INIT_REEST_TO);