From: Tony Lindgren Date: Wed, 19 Apr 2023 11:54:22 +0000 (+0300) Subject: serial: core: Disable uart_start() on uart_remove_one_port() X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=63f4c34561718a349d321105adab028cbf212d57;p=linux.git serial: core: Disable uart_start() on uart_remove_one_port() While rebinding a uart device in a loop I noticed we may see a tx related race on uart_remove_one_port(): uart_write from n_tty_write n_tty_write from file_tty_write.constprop.0 file_tty_write.constprop.0 from vfs_write vfs_write from ksys_write ksys_write from ret_fast_syscall Let's disallow tx on port->UPF_DEAD. This flag gets set before we start tearing down the port in uart_remove_one_port(). Signed-off-by: Tony Lindgren Link: https://lore.kernel.org/r/20230419115423.59957-1-tony@atomide.com Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c index 59b62fa2e2873..54e82f476a2cc 100644 --- a/drivers/tty/serial/serial_core.c +++ b/drivers/tty/serial/serial_core.c @@ -135,7 +135,7 @@ static void __uart_start(struct tty_struct *tty) struct uart_state *state = tty->driver_data; struct uart_port *port = state->uart_port; - if (port && !uart_tx_stopped(port)) + if (port && !(port->flags & UPF_DEAD) && !uart_tx_stopped(port)) port->ops->start_tx(port); }