[PATCH 4.4 013/146] USB: EHCI: declare hostpc register as zero-length array

Greg Kroah-Hartman
2016-07-25T20:57:15Z

From: Alan Stern <stern@rowland.harvard.edu>

commit 7e8b3dfef16375dbfeb1f36a83eb9f27117c51fd upstream.

The HOSTPC extension registers found in some EHCI implementations form
a variable-length array, with one element for each port. Therefore
the hostpc field in struct ehci_regs should be declared as a
zero-length array, not a single-element array.

This fixes a problem reported by UBSAN.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-by: Wilfried Klaebe <linux-kernel@lebenslange-mailadresse.de>
Tested-by: Wilfried Klaebe <linux-kernel@lebenslange-mailadresse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
include/linux/usb/ehci_def.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/include/linux/usb/ehci_def.h
+++ b/include/linux/usb/ehci_def.h
@@ -180,11 +180,11 @@ struct ehci_regs {
* PORTSCx
*/
/* HOSTPC: offset 0x84 */
- u32 hostpc[1]; /* HOSTPC extension */
+ u32 hostpc[0]; /* HOSTPC extension */
#define HOSTPC_PHCD (1<<22) /* Phy clock disable */
#define HOSTPC_PSPD (3<<25) /* Port speed detection */

- u32 reserved5[16];
+ u32 reserved5[17];

/* USBMODE_EX: offset 0xc8 */
u32 usbmode_ex; /* USB Device mode extension */