linux-kernel - [PATCH] of: Fix __of_device_is

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <1389582448-7489-1-git-send-email-Li.Xiubo@freescale.com>
Date:	Mon, 13 Jan 2014 11:07:28 +0800
From:	Xiubo Li <Li.Xiubo@...escale.com>
To:	<grant.likely@...aro.org>, <robh+dt@...nel.org>
CC:	<devicetree@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
	Xiubo Li <Li.Xiubo@...escale.com>
Subject: [PATCH] of: Fix __of_device_is_available check

>From IEEE 1275, there defined a standard 'status' property indicating the
operational status of one device. The 'status' property has four possible
values: 'okay/ok', 'disabled', 'fail' and 'fail-xxx'.

If it is absent, that means the status of the device is unknown or okay.

The __of_device_is_available checks the state of the 'status' property of
a device. If the property is absent or set to 'okay/ok', it returns 1.
Otherwise it returns 0.

While in __of_device_is_available:
 >	status = of_get_property(device, "status", &statlen);
 >	if (status == NULL)
 >		return 1;
The status value returned from 'of_get_property()' will be NULL in two cases:
Firstly: the 'device' value (device node) is NULL.
Secondly: the 'status' property is actaully not exist.

If the device node is NULL, the __of_device_is_available will return true,
that will mean the absent state of the 'status' property.

So this add the device node check before checking the 'status' property's
state, and if the device node is not exist, 0 will be returned.

Signed-off-by: Xiubo Li <Li.Xiubo@...escale.com>
---
 drivers/of/base.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/of/base.c b/drivers/of/base.c
index f807d0e..ba195fb 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -415,6 +415,9 @@ static int __of_device_is_available(const struct device_node *device)
 	const char *status;
 	int statlen;
 
+	if (!device)
+		return 0;
+
 	status = __of_get_property(device, "status", &statlen);
 	if (status == NULL)
 		return 1;
-- 
1.8.4


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/