[PATCH 3.14 14/53] USB: EHCI: declare hostpc register as zero-length array

From: Greg Kroah-Hartman
Date: Mon Jul 25 2016 - 17:14:53 EST


3.14-stable review patch. If anyone has any objections, please let me know.

------------------

From: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>

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@xxxxxxxxxxxxxxxxxxx>
Reported-by: Wilfried Klaebe <linux-kernel@xxxxxxxxxxxxxxxxxxxxxxxxxx>
Tested-by: Wilfried Klaebe <linux-kernel@xxxxxxxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
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
@@ -178,11 +178,11 @@ 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 */