From 98a1a0c7a321a46e805df289c7d385a9b1b4c661 Mon Sep 17 00:00:00 2001
From: Colin Ian King <colin.king@canonical.com>
Date: Thu, 5 Jul 2018 14:36:47 +0100
Subject: [PATCH] usb: typec: unlock dp->lock on error exit path, and also zero
ret if successful
Git-commit: 98a1a0c7a321a46e805df289c7d385a9b1b4c661
References: FATE#326325
Patch-mainline: v4.19
One of the error handling paths forgets to unlock dp->lock on the error
exit path leading to a potential lock-up. Also the return path for a
successful call to the function configuration_store can return an
uninitialized error return code if dp->alt->active is false, so ensure
ret is zeroed on the successful exit path to avoid garbage being returned.
Detected by CoverityScan, CID#1471597 ("Unitialized scalar variable")
Fixes: 0e3bb7d6894d ("usb: typec: Add driver for DisplayPort alternate mode")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Oliver Neukum <oneukum@suse.com>
---
drivers/usb/typec/altmodes/displayport.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/drivers/usb/typec/altmodes/displayport.c b/drivers/usb/typec/altmodes/displayport.c
index ef12b15bd484..3f06e94771a7 100644
--- a/drivers/usb/typec/altmodes/displayport.c
+++ b/drivers/usb/typec/altmodes/displayport.c
@@ -333,7 +333,7 @@ configuration_store(struct device *dev, struct device_attribute *attr,
u32 conf;
u32 cap;
int con;
- int ret;
+ int ret = 0;
con = sysfs_match_string(configurations, buf);
if (con < 0)
@@ -349,8 +349,10 @@ configuration_store(struct device *dev, struct device_attribute *attr,
cap = DP_CAP_CAPABILITY(dp->alt->vdo);
if ((con == DP_CONF_DFP_D && !(cap & DP_CAP_DFP_D)) ||
- (con == DP_CONF_UFP_D && !(cap & DP_CAP_UFP_D)))
- return -EINVAL;
+ (con == DP_CONF_UFP_D && !(cap & DP_CAP_UFP_D))) {
+ ret = -EINVAL;
+ goto err_unlock;
+ }
conf = dp->data.conf & ~DP_CONF_DUAL_D;
conf |= con;
--
2.16.4