tty, serial: Fix race and NULL check in uart_close()
Commit 46d57a449aa1 ("serial: use tty_port pointers in the core code")
contained two bugs that causes (rare) crashes:
- the rename typoed one site
- a NULL check was missed
Reported-and-tested-by: Ingo Molnar <mingo@elte.hu>
Cc: Greg KH <gregkh@suse.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c
index 1689bda..dcc7244 100644
--- a/drivers/serial/serial_core.c
+++ b/drivers/serial/serial_core.c
@@ -1270,6 +1270,9 @@
BUG_ON(!kernel_locked());
+ if (!state)
+ return;
+
uport = state->uart_port;
port = &state->port;
@@ -1316,9 +1319,9 @@
*/
if (port->flags & ASYNC_INITIALIZED) {
unsigned long flags;
- spin_lock_irqsave(&port->lock, flags);
+ spin_lock_irqsave(&uport->lock, flags);
uport->ops->stop_rx(uport);
- spin_unlock_irqrestore(&port->lock, flags);
+ spin_unlock_irqrestore(&uport->lock, flags);
/*
* Before we drop DTR, make sure the UART transmitter
* has completely drained; this is especially