From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jesper Juhl Subject: [PATCH][hid] Fix a NULL pointer dereference when we fail to allocate memory Date: Sun, 22 Jul 2007 00:06:20 +0200 Message-ID: <200707220006.20359.jesper.juhl@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline Sender: owner-linux-input@atrey.karlin.mff.cuni.cz List-Help: List-Owner: List-Post: List-Unsubscribe: To: Jiri Kosina Cc: Linux Kernel Mailing List , Michael Haboustak , Andreas Gal , Vojtech Pavlik , Greg Kroah-Hartman , linux-input@atrey.karlin.mff.cuni.cz, Jesper Juhl List-Id: linux-input@vger.kernel.org Hi, If, in usb_hid_configure(), we fail to allocate storage for 'usbhid', "if (!(usbhid = kzalloc(sizeof(struct usbhid_device), GFP_KERNEL)))", then we'll jump to the 'fail:' label where we have this code: usb_free_urb(usbhid->urbin); usb_free_urb(usbhid->urbout); usb_free_urb(usbhid->urbctrl); Since we got here because we couldn't allocate storage for 'usbhid', what we have here is a NULL pointer dereference - ouch... This patch solves that little problem by adding a new 'fail_no_usbhid:' label after the problematic calls to usb_free_urb() and jumps to that one instead, in the problem case. Signed-off-by: Jesper Juhl --- drivers/hid/usbhid/hid-core.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-) diff --git a/drivers/hid/usbhid/hid-core.c b/drivers/hid/usbhid/hid-core.c index b2baeae..3ff7468 100644 --- a/drivers/hid/usbhid/hid-core.c +++ b/drivers/hid/usbhid/hid-core.c @@ -743,7 +743,7 @@ static struct hid_device *usb_hid_configure(struct usb_interface *intf) hid->quirks = quirks; if (!(usbhid = kzalloc(sizeof(struct usbhid_device), GFP_KERNEL))) - goto fail; + goto fail_no_usbhid; hid->driver_data = usbhid; usbhid->hid = hid; @@ -877,6 +877,7 @@ fail: usb_free_urb(usbhid->urbin); usb_free_urb(usbhid->urbout); usb_free_urb(usbhid->urbctrl); +fail_no_usbhid: hid_free_buffers(dev, hid); hid_free_device(hid);