From 66688f6191c9299ccb8ccf3e1dc99cc59b194587 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.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/usb/serial/ti_usb_3410_5052.h b/drivers/usb/serial/ti_usb_3410_5052.h index 4a2423e84d558..d0ca4e4abb689 100644 --- a/drivers/usb/serial/ti_usb_3410_5052.h +++ b/drivers/usb/serial/ti_usb_3410_5052.h @@ -223,7 +223,7 @@ struct ti_interrupt { } __attribute__((packed)); /* Interrupt codes */ -#define TI_GET_PORT_FROM_CODE(c) (((c) >> 4) - 3) +#define TI_GET_PORT_FROM_CODE(c) (((c) >> 6) & 0x01) #define TI_GET_FUNC_FROM_CODE(c) ((c) & 0x0f) #define TI_CODE_HARDWARE_ERROR 0xFF #define TI_CODE_DATA_ERROR 0x03