This is a note to let you know that I've just added the patch titled SUNRPC: Ensure we flush any closed sockets before xs_xprt_free() to the 5.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: sunrpc-ensure-we-flush-any-closed-sockets-before-xs_xprt_free.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From f00432063db1a0db484e85193eccc6845435b80e Mon Sep 17 00:00:00 2001 From: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx> Date: Sun, 3 Apr 2022 15:58:11 -0400 Subject: SUNRPC: Ensure we flush any closed sockets before xs_xprt_free() From: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx> commit f00432063db1a0db484e85193eccc6845435b80e upstream. We must ensure that all sockets are closed before we call xprt_free() and release the reference to the net namespace. The problem is that calling fput() will defer closing the socket until delayed_fput() gets called. Let's fix the situation by allowing rpciod and the transport teardown code (which runs on the system wq) to call __fput_sync(), and directly close the socket. Reported-by: Felix Fu <foyjog@xxxxxxxxx> Acked-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx> Fixes: a73881c96d73 ("SUNRPC: Fix an Oops in udp_poll()") Cc: stable@xxxxxxxxxxxxxxx # 5.1.x: 3be232f11a3c: SUNRPC: Prevent immediate close+reconnect Cc: stable@xxxxxxxxxxxxxxx # 5.1.x: 89f42494f92f: SUNRPC: Don't call connect() more than once on a TCP socket Cc: stable@xxxxxxxxxxxxxxx # 5.1.x Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx> Cc: Meena Shanmugam <meenashanmugam@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/file_table.c | 1 + include/trace/events/sunrpc.h | 1 - net/sunrpc/xprt.c | 7 +------ net/sunrpc/xprtsock.c | 16 +++++++++++++--- 4 files changed, 15 insertions(+), 10 deletions(-) --- a/fs/file_table.c +++ b/fs/file_table.c @@ -375,6 +375,7 @@ void __fput_sync(struct file *file) } EXPORT_SYMBOL(fput); +EXPORT_SYMBOL(__fput_sync); void __init files_init(void) { --- a/include/trace/events/sunrpc.h +++ b/include/trace/events/sunrpc.h @@ -976,7 +976,6 @@ DEFINE_RPC_XPRT_LIFETIME_EVENT(connect); DEFINE_RPC_XPRT_LIFETIME_EVENT(disconnect_auto); DEFINE_RPC_XPRT_LIFETIME_EVENT(disconnect_done); DEFINE_RPC_XPRT_LIFETIME_EVENT(disconnect_force); -DEFINE_RPC_XPRT_LIFETIME_EVENT(disconnect_cleanup); DEFINE_RPC_XPRT_LIFETIME_EVENT(destroy); DECLARE_EVENT_CLASS(rpc_xprt_event, --- a/net/sunrpc/xprt.c +++ b/net/sunrpc/xprt.c @@ -929,12 +929,7 @@ void xprt_connect(struct rpc_task *task) if (!xprt_lock_write(xprt, task)) return; - if (test_and_clear_bit(XPRT_CLOSE_WAIT, &xprt->state)) { - trace_xprt_disconnect_cleanup(xprt); - xprt->ops->close(xprt); - } - - if (!xprt_connected(xprt)) { + if (!xprt_connected(xprt) && !test_bit(XPRT_CLOSE_WAIT, &xprt->state)) { task->tk_rqstp->rq_connect_cookie = xprt->connect_cookie; rpc_sleep_on_timeout(&xprt->pending, task, NULL, xprt_request_timeout(task->tk_rqstp)); --- a/net/sunrpc/xprtsock.c +++ b/net/sunrpc/xprtsock.c @@ -880,7 +880,7 @@ static int xs_local_send_request(struct /* Close the stream if the previous transmission was incomplete */ if (xs_send_request_was_aborted(transport, req)) { - xs_close(xprt); + xprt_force_disconnect(xprt); return -ENOTCONN; } @@ -918,7 +918,7 @@ static int xs_local_send_request(struct -status); fallthrough; case -EPIPE: - xs_close(xprt); + xprt_force_disconnect(xprt); status = -ENOTCONN; } @@ -1205,6 +1205,16 @@ static void xs_reset_transport(struct so if (sk == NULL) return; + /* + * Make sure we're calling this in a context from which it is safe + * to call __fput_sync(). In practice that means rpciod and the + * system workqueue. + */ + if (!(current->flags & PF_WQ_WORKER)) { + WARN_ON_ONCE(1); + set_bit(XPRT_CLOSE_WAIT, &xprt->state); + return; + } if (atomic_read(&transport->xprt.swapper)) sk_clear_memalloc(sk); @@ -1228,7 +1238,7 @@ static void xs_reset_transport(struct so mutex_unlock(&transport->recv_mutex); trace_rpc_socket_close(xprt, sock); - fput(filp); + __fput_sync(filp); xprt_disconnect_done(xprt); } Patches currently in stable-queue which might be from trond.myklebust@xxxxxxxxxxxxxxx are queue-5.15/nfs-fix-broken-handling-of-the-softreval-mount-optio.patch queue-5.15/sunrpc-ensure-we-flush-any-closed-sockets-before-xs_xprt_free.patch queue-5.15/sunrpc-ensure-that-the-gssproxy-client-can-start-in-a-connected-state.patch