[PATCH v1] usb: isp1760: increase buffer size to avoid overflow

["Alexey V. Vissarionov" <gremlin@altlinux.org>]

When isp1760_udc_init_hw() calls isp1760_set_pullup(), its call of
isp1760_field_set() may access the udc->fields array beyond the size
of DC_FIELD_MAX up to HC_FIELD_MAX, which is (now) bigger. Increase
the buffer size to max(DC_FIELD_MAX,HC_FIELD_MAX) to avoid possible
overflow.

Found by ALT Linux Team (altlinux.org) and Linux Verification Center
(linuxtesting.org).

Fixes: 1da9e1c06873 ("usb: isp1760: move to regmap for register access")
Signed-off-by: Alexey V. Vissarionov <gremlin@altlinux.org>
---
 drivers/usb/isp1760/isp1760-hcd.h  | 2 +-
 drivers/usb/isp1760/isp1760-regs.h | 3 +++
 drivers/usb/isp1760/isp1760-udc.h  | 2 +-
 3 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/isp1760/isp1760-hcd.h b/drivers/usb/isp1760/isp1760-hcd.h
index ee3063a34de3bccf..34dacde96c4ae3cf 100644
--- a/drivers/usb/isp1760/isp1760-hcd.h
+++ b/drivers/usb/isp1760/isp1760-hcd.h
@@ -50,7 +50,7 @@ struct isp1760_hcd {
 	void __iomem		*base;
 
 	struct regmap		*regs;
-	struct regmap_field	*fields[HC_FIELD_MAX];
+	struct regmap_field	*fields[DC_HC_FIELD_MAX];
 
 	bool			is_isp1763;
 	const struct isp1760_memory_layout	*memory_layout;
diff --git a/drivers/usb/isp1760/isp1760-regs.h b/drivers/usb/isp1760/isp1760-regs.h
index 3a6751197e970013..a5a442015887ce0b 100644
--- a/drivers/usb/isp1760/isp1760-regs.h
+++ b/drivers/usb/isp1760/isp1760-regs.h
@@ -267,6 +267,9 @@ enum isp176x_device_controller_fields {
 	DC_FIELD_MAX,
 };
 
+#define	DC_HC_FIELD_MAX	\
+	(DC_FIELD_MAX > HC_FIELD_MAX ? DC_FIELD_MAX : HC_FIELD_MAX)
+
 /* ISP1763 */
 /* Initialization Registers */
 #define ISP1763_DC_ADDRESS		0x00
diff --git a/drivers/usb/isp1760/isp1760-udc.h b/drivers/usb/isp1760/isp1760-udc.h
index 22044e86bc0ecb84..609444bea306ba81 100644
--- a/drivers/usb/isp1760/isp1760-udc.h
+++ b/drivers/usb/isp1760/isp1760-udc.h
@@ -69,7 +69,7 @@ struct isp1760_udc {
 	char *irqname;
 
 	struct regmap *regs;
-	struct regmap_field *fields[DC_FIELD_MAX];
+	struct regmap_field *fields[DC_HC_FIELD_MAX];
 
 	struct usb_gadget_driver *driver;
 	struct usb_gadget gadget;

-- 
Alexey V. Vissarionov
gremlin ПРИ altlinux ТЧК org; +vii-cmiii-ccxxix-lxxix-xlii
GPG: 0D92F19E1C0DC36E27F61A29CD17E2B43D879005 @ hkp://keys.gnupg.net