From 5dfdd24eb3d39d815bc952ae98128e967c9bba49 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Tue, 21 Aug 2018 11:59:53 +0200 Subject: USB: serial: ti_usb_3410_5052: fix array underflow in completion handler 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 --- drivers/usb/serial/ti_usb_3410_5052.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/usb/serial/ti_usb_3410_5052.c') diff --git a/drivers/usb/serial/ti_usb_3410_5052.c b/drivers/usb/serial/ti_usb_3410_5052.c index 3010878f7f8e..e3c5832337e0 100644 --- a/drivers/usb/serial/ti_usb_3410_5052.c +++ b/drivers/usb/serial/ti_usb_3410_5052.c @@ -1119,7 +1119,7 @@ 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) -- cgit v1.2.3-59-g8ed1b