From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jean Delvare Subject: Re: [PATCH 02/14] HID: i2c-hid: fix memory corruption due to missing hid declaration Date: Tue, 4 Dec 2012 22:42:05 +0100 Message-ID: <20121204224205.58420e3f@endymion.delvare> References: <1354634875-5182-1-git-send-email-benjamin.tissoires@gmail.com> <1354634875-5182-3-git-send-email-benjamin.tissoires@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1354634875-5182-3-git-send-email-benjamin.tissoires-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Benjamin Tissoires Cc: Jiri Kosina , linux-input-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-i2c@vger.kernel.org On Tue, 4 Dec 2012 16:27:43 +0100, Benjamin Tissoires wrote: > 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 | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/hid/i2c-hid/i2c-hid.c b/drivers/hid/i2c-hid/i2c-hid.c > index 0fbb229..ad771a7 100644 > --- a/drivers/hid/i2c-hid/i2c-hid.c > +++ b/drivers/hid/i2c-hid/i2c-hid.c > @@ -68,6 +68,7 @@ struct i2c_hid_desc { > __le16 wVendorID; > __le16 wProductID; > __le16 wVersionID; > + __le32 reserved; > } __packed; > > struct i2c_hid_cmd { > @@ -778,7 +779,7 @@ 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) { > + if (!dsize || dsize > sizeof(struct i2c_hid_desc)) { Shouldn't !dsize rather be dsize < 4? You're reading hdesc->bcdVersion, which is only defined if dsize >= 4 if I understand the code correctly. > dev_err(&client->dev, "weird size of HID descriptor (%u)\n", > dsize); > return -ENODEV; -- Jean Delvare