hwmon: (applesmc) Limit key length in warning messages

commit ac852edb47b15900886ba2564eeeb13b3b526e3e upstream.

Key lookups may call read_smc() with a fixed-length key string,
and if the lookup fails, trailing stack content may appear in the
kernel log. Fixed with this patch.

Signed-off-by: Henrik Rydberg <rydberg@euromail.se>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/drivers/hwmon/applesmc.c b/drivers/hwmon/applesmc.c
index 4c0743660e9..d99aa848477 100644
--- a/drivers/hwmon/applesmc.c
+++ b/drivers/hwmon/applesmc.c
@@ -215,7 +215,7 @@ static int read_smc(u8 cmd, const char *key, u8 *buffer, u8 len)
         int i;
 
         if (send_command(cmd) || send_argument(key)) {
-                pr_warn("%s: read arg fail\n", key);
+                pr_warn("%.4s: read arg fail\n", key);
                 return -EIO;
         }
 
@@ -223,7 +223,7 @@ static int read_smc(u8 cmd, const char *key, u8 *buffer, u8 len)
 
         for (i = 0; i < len; i++) {
                 if (__wait_status(0x05)) {
-                        pr_warn("%s: read data fail\n", key);
+                        pr_warn("%.4s: read data fail\n", key);
                         return -EIO;
                 }
                 buffer[i] = inb(APPLESMC_DATA_PORT);