[PATCH 3.16 015/233] PowerCap: Fix an error code in powercap_register_zone()

From: Ben Hutchings
Date: Sat Sep 09 2017 - 18:33:51 EST

3.16.48-rc1 review patch. If anyone has any objections, please let me know.


From: Dan Carpenter <dan.carpenter@xxxxxxxxxx>

commit 216c4e9db4c9d1d2a382b42880442dc632cd47d9 upstream.

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

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@xxxxxxxxxx>
Reviewed-by: Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
drivers/powercap/powercap_sys.c | 1 +
1 file changed, 1 insertion(+)

--- a/drivers/powercap/powercap_sys.c
+++ b/drivers/powercap/powercap_sys.c
@@ -538,6 +538,7 @@ struct powercap_zone *powercap_register_

power_zone->id = result;
+ result = -ENOMEM;
power_zone->name = kstrdup(name, GFP_KERNEL);
if (!power_zone->name)
goto err_name_alloc;