From mboxrd@z Thu Jan 1 00:00:00 1970 From: Benjamin Tissoires Subject: [PATCH v2 1/4] HID: i2c-hid: fix memory corruption due to missing hid declaration Date: Wed, 5 Dec 2012 15:02:53 +0100 Message-ID: <1354716176-12558-2-git-send-email-benjamin.tissoires@gmail.com> References: <1354716176-12558-1-git-send-email-benjamin.tissoires@gmail.com> Return-path: In-Reply-To: <1354716176-12558-1-git-send-email-benjamin.tissoires@gmail.com> Sender: linux-input-owner@vger.kernel.org To: Benjamin Tissoires , Jiri Kosina , Jean Delvare , linux-input@vger.kernel.org, linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: linux-i2c@vger.kernel.org HID descriptors contains 4 bytes of reserved field. The previous implementation was overriding the next fields in struct i2c_hid. Signed-off-by: Benjamin Tissoires --- drivers/hid/i2c-hid/i2c-hid.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/hid/i2c-hid/i2c-hid.c b/drivers/hid/i2c-hid/i2c-hid.c index 7062df2..34cca42 100644 --- a/drivers/hid/i2c-hid/i2c-hid.c +++ b/drivers/hid/i2c-hid/i2c-hid.c @@ -69,6 +69,7 @@ struct i2c_hid_desc { __le16 wVendorID; __le16 wProductID; __le16 wVersionID; + __le32 reserved; } __packed; struct i2c_hid_cmd { @@ -776,7 +777,13 @@ static int __devinit i2c_hid_fetch_hid_descriptor(struct i2c_hid *ihid) } dsize = le16_to_cpu(hdesc->wHIDDescLength); - if (!dsize || dsize > HID_MAX_DESCRIPTOR_SIZE) { + /* + * the size of the HID descriptor should at least contain + * its size and the bcdVersion (4 bytes), and should not be greater + * than sizeof(struct i2c_hid_desc) as we directly fill this struct + * through i2c_hid_command. + */ + if (dsize < 4 || dsize > sizeof(struct i2c_hid_desc)) { dev_err(&client->dev, "weird size of HID descriptor (%u)\n", dsize); return -ENODEV; -- 1.8.0.1