linux-kernel - [PATCH v2] Input: elan_i2c - check if device is there before really probing

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]

Date:   Mon, 8 May 2017 17:45:53 -0700
From:   Dmitry Torokhov <dmitry.torokhov@...il.com>
To:     linux-input@...r.kernel.org
Cc:     KT Liao <ktalex.liao@...il.com>,
        Benjamin Tissoires <benjamin.tissoires@...hat.com>,
        Guenter Roeck <linux@...ck-us.net>,
        linux-kernel@...r.kernel.org
Subject: [PATCH v2] Input: elan_i2c - check if device is there before really
 probing

Before trying to properly initialize the touchpad and generate bunch of
errors, let's first see it there is anything at the given address. If we
get error, fail silently with -ENXIO.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@...il.com>
---

v2: switched over to i2c_smbus_read_byte() as Guenter suggested

 drivers/input/mouse/elan_i2c_core.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/input/mouse/elan_i2c_core.c b/drivers/input/mouse/elan_i2c_core.c
index 5d3b53dd2fa2..3b616cb7c67f 100644
--- a/drivers/input/mouse/elan_i2c_core.c
+++ b/drivers/input/mouse/elan_i2c_core.c
@@ -1091,6 +1091,13 @@ static int elan_probe(struct i2c_client *client,
 		return error;
 	}
 
+	/* Make sure there is something at this address */
+	error = i2c_smbus_read_byte(client);
+	if (error < 0) {
+		dev_dbg(&client->dev, "nothing at this address: %d\n", error);
+		return -ENXIO;
+	}
+
 	/* Initialize the touchpad. */
 	error = elan_initialize(data);
 	if (error)
-- 
2.13.0.rc2.291.g57267f2277-goog


-- 
Dmitry