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@xxxxxxxxxxxxxxx> 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@xxxxxxxxxxxxxxx> Reviewed-by: Yehezkel Bernat <yehezkelshb@xxxxxxxxx> Cc: stable <stable@xxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- 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