This is a note to let you know that I've just added the patch titled
serial: 8250: fix return error code in serial8250_request_std_resource()
to the 4.19-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:
serial-8250-fix-return-error-code-in-serial8250_request_std_resource.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 6e690d54cfa802f939cefbd2fa2c91bd0b8bd1b6 Mon Sep 17 00:00:00 2001
From: Yi Yang <yiyang13@xxxxxxxxxx>
Date: Tue, 28 Jun 2022 16:35:15 +0800
Subject: serial: 8250: fix return error code in serial8250_request_std_resource()
From: Yi Yang <yiyang13@xxxxxxxxxx>
commit 6e690d54cfa802f939cefbd2fa2c91bd0b8bd1b6 upstream.
If port->mapbase = NULL in serial8250_request_std_resource() , it need
return a error code instead of 0. If uart_set_info() fail to request new
regions by serial8250_request_std_resource() but the return value of
serial8250_request_std_resource() is 0, The system incorrectly considers
that the resource application is successful and does not attempt to
restore the old setting. A null pointer reference is triggered when the
port resource is later invoked.
Signed-off-by: Yi Yang <yiyang13@xxxxxxxxxx>
Cc: stable <stable@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20220628083515.64138-1-yiyang13@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/tty/serial/8250/8250_port.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -2917,8 +2917,10 @@ static int serial8250_request_std_resour
case UPIO_MEM32BE:
case UPIO_MEM16:
case UPIO_MEM:
- if (!port->mapbase)
+ if (!port->mapbase) {
+ ret = -EINVAL;
break;
+ }
if (!request_mem_region(port->mapbase, size, "serial")) {
ret = -EBUSY;
Patches currently in stable-queue which might be from yiyang13@xxxxxxxxxx are
queue-4.19/serial-8250-fix-return-error-code-in-serial8250_request_std_resource.patch
