[PATCH v7 3/6] power: supply: Add error checking of psy desc during registration

From: Adam Thomson <Adam.Thomson.Opensource@diasemi.com>
To: Heikki Krogerus <heikki.krogerus@linux.intel.com>,
	Guenter Roeck <linux@roeck-us.net>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Sebastian Reichel <sre@kernel.org>,
	Hans de Goede <hdegoede@redhat.com>, Jun Li <jun.li@nxp.com>
Cc: <linux-usb@vger.kernel.org>, <linux-pm@vger.kernel.org>,
	<linux-kernel@vger.kernel.org>, <support.opensource@diasemi.com>
Subject: [PATCH v7 3/6] power: supply: Add error checking of psy desc during registration
Date: Fri, 23 Mar 2018 10:12:23 +0000	[thread overview]
Message-ID: <84159a4df772e123d850561eff38ece7577e816f.1521799705.git.Adam.Thomson.Opensource@diasemi.com> (raw)
In-Reply-To: <cover.1521799705.git.Adam.Thomson.Opensource@diasemi.com>

Currently there's no error checking of this parameter in the
registration function and it's blindly added to psy class and
subsequently used as is. For example if this is NULL the call
to psy_register_thermal() will try to dereference the pointer
thus causing a kernel dump.

This commit updates the registration code to add some basic
checks on the desc pointer validity, name, and presence of
properties.

Signed-off-by: Adam Thomson <Adam.Thomson.Opensource@diasemi.com>
---
 drivers/power/supply/power_supply_core.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/power/supply/power_supply_core.c b/drivers/power/supply/power_supply_core.c
index 82f998a..64f6449 100644
--- a/drivers/power/supply/power_supply_core.c
+++ b/drivers/power/supply/power_supply_core.c
@@ -849,6 +849,9 @@ static void psy_unregister_cooler(struct power_supply *psy)
 		pr_warn("%s: Expected proper parent device for '%s'\n",
 			__func__, desc->name);
 
+	if (!desc || !desc->name || !desc->properties || !desc->num_properties)
+		return ERR_PTR(-EINVAL);
+
 	psy = kzalloc(sizeof(*psy), GFP_KERNEL);
 	if (!psy)
 		return ERR_PTR(-ENOMEM);
-- 
1.9.1
