patch "thunderbolt: Check return value of tb_sw_read() in usb4_switch_op()" added to usb-linus

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    thunderbolt: Check return value of tb_sw_read() in usb4_switch_op()

to my usb git tree which can be found at
    git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-linus branch.

The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)

The patch will hopefully also be merged in Linus's tree for the
next -rc kernel release.

If you have any questions about this process, please let me know.


From c3bf9930921b33edb31909006607e478751a6f5e Mon Sep 17 00:00:00 2001
From: Mika Westerberg <mika.westerberg@linux.intel.com>
Date: Thu, 9 Apr 2020 10:18:10 +0300
Subject: thunderbolt: Check return value of tb_sw_read() in usb4_switch_op()

The function misses checking return value of tb_sw_read() before it
accesses the value that was read. Fix this by checking the return value
first.

Fixes: b04079837b20 ("thunderbolt: Add initial support for USB4")
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Yehezkel Bernat <yehezkelshb@gmail.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/thunderbolt/usb4.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/thunderbolt/usb4.c b/drivers/thunderbolt/usb4.c
index 3d084cec136f..50c7534ba31e 100644
--- a/drivers/thunderbolt/usb4.c
+++ b/drivers/thunderbolt/usb4.c
@@ -182,6 +182,9 @@ static int usb4_switch_op(struct tb_switch *sw, u16 opcode, u8 *status)
 		return ret;
 
 	ret = tb_sw_read(sw, &val, TB_CFG_SWITCH, ROUTER_CS_26, 1);
+	if (ret)
+		return ret;
+
 	if (val & ROUTER_CS_26_ONS)
 		return -EOPNOTSUPP;
 
-- 
2.26.2