From a98152a6feaa64c33684097eaeb4ff225fab8fca Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Tue, 21 Aug 2018 11:59:53 +0200 Subject: [PATCH] USB: serial: ti_usb_3410_5052: fix array underflow in completion handler commit 5dfdd24eb3d39d815bc952ae98128e967c9bba49 upstream. Similarly to a recently reported bug in io_ti, a malicious USB device could set port_number to a negative value and we would underflow the port array in the interrupt completion handler. As these devices only have one or two ports, fix this by making sure we only consider the seventh bit when determining the port number (and ignore bits 0xb0 which are typically set to 0x30). Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable Signed-off-by: Johan Hovold Signed-off-by: Greg Kroah-Hartman --- drivers/usb/serial/ti_usb_3410_5052.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/usb/serial/ti_usb_3410_5052.c b/drivers/usb/serial/ti_usb_3410_5052.c index 8fc3854..57e9f66 100644 --- a/drivers/usb/serial/ti_usb_3410_5052.c +++ b/drivers/usb/serial/ti_usb_3410_5052.c @@ -1123,7 +1123,7 @@ static void ti_break(struct tty_struct *tty, int break_state) static int ti_get_port_from_code(unsigned char code) { - return (code >> 4) - 3; + return (code >> 6) & 0x01; } static int ti_get_func_from_code(unsigned char code) -- 2.7.4