-----Original Message-----
From: Arnd Bergmann [mailto:arnd@arndb.de]
Sent: Friday, July 14, 2017 7:07 AM
To: linux-kernel@vger.kernel.org; Darren Hart <dvhart@infradead.org>; Andy
Shevchenko [off-list ref]
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>; Linus Torvalds
[off-list ref]; Guenter Roeck [off-list ref];
akpm@linux-foundation.org; netdev@vger.kernel.org; David S . Miller
[off-list ref]; James E . J . Bottomley [off-list ref];
Martin K . Petersen [off-list ref]; linux-scsi@vger.kernel.org;
x86@kernel.org; Arnd Bergmann [off-list ref]; Limonciello, Mario
[off-list ref]; Arvind Yadav [off-list ref];
platform-driver-x86@vger.kernel.org
Subject: [PATCH 17/22] platform/x86: alienware-wmi: fix format string overflow
warning

gcc points out a possible format string overflow for a large value of 'zone':

drivers/platform/x86/alienware-wmi.c: In function 'alienware_wmi_init':
drivers/platform/x86/alienware-wmi.c:461:24: error: '%02X' directive writing
between 2 and 8 bytes into a region of size 6 [-Werror=format-overflow=]
   sprintf(buffer, "zone%02X", i);
                        ^~~~
drivers/platform/x86/alienware-wmi.c:461:19: note: directive argument in the
range [0, 2147483646]
   sprintf(buffer, "zone%02X", i);
                   ^~~~~~~~~~
drivers/platform/x86/alienware-wmi.c:461:3: note: 'sprintf' output between 7 and
13 bytes into a destination of size 10

While the zone should never be that large, it's easy to make the
buffer a few bytes longer so gcc can prove this to be safe.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/platform/x86/alienware-wmi.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/platform/x86/alienware-wmi.c

b/drivers/platform/x86/alienware-wmi.c
index 0831b428c217..acc01242da82 100644

--- a/drivers/platform/x86/alienware-wmi.c
+++ b/drivers/platform/x86/alienware-wmi.c

@@ -421,7 +421,7 @@ static DEVICE_ATTR(lighting_control_state, 0644,

show_control_state,
 static int alienware_zone_init(struct platform_device *dev)
 {
 	int i;
-	char buffer[10];
+	char buffer[13];
 	char *name;

 	if (interface == WMAX) {
--
2.9.0