From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Wed, 10 May 2017 19:40:06 +0000 (+0300)
Subject: PowerCap: Fix an error code in powercap_register_zone()
X-Git-Tag: v4.1.52~272
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a33128be9f9152408200b9014f064a9ae28e88c0;p=thirdparty%2Fkernel%2Fstable.git

PowerCap: Fix an error code in powercap_register_zone()

[ Upstream commit 216c4e9db4c9d1d2a382b42880442dc632cd47d9 ]

In the current code we accidentally return the successful result from
idr_alloc() instead of a negative error pointer.  The caller is looking
for an error pointer and so it treats the returned value as a valid
pointer.

This one might be a bit serious because if it lets people get around the
kernel's protection for remapping NULL.  I'm not sure.

Fixes: 75d2364ea0ca (PowerCap: Add class driver)
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
---

diff --git a/drivers/powercap/powercap_sys.c b/drivers/powercap/powercap_sys.c
index 84419af16f777..fd12ccc11e262 100644
--- a/drivers/powercap/powercap_sys.c
+++ b/drivers/powercap/powercap_sys.c
@@ -538,6 +538,7 @@ struct powercap_zone *powercap_register_zone(
 
 	power_zone->id = result;
 	idr_init(&power_zone->idr);
+	result = -ENOMEM;
 	power_zone->name = kstrdup(name, GFP_KERNEL);
 	if (!power_zone->name)
 		goto err_name_alloc;