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authorBjørn Mork <bjorn@mork.no>2012-05-09 13:53:23 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-05-11 15:19:22 -0700
commit6286d85e8efdb59252d1ceb99a56fa6b0b11526c (patch)
tree37b91b39c74370899aedd708921f6774850cd52a /drivers/usb/class
parent6b0b79d38806481c1c8fffa7c5842f3c83679a42 (diff)
USB: cdc-wdm: remove from device list on disconnect
Prevents dereferencing an invalid struct usb_interface pointer. Always delete entry from device list whether or not the rest of the device state cleanup is postponed. The device list uses desc->intf as key, and wdm_open will dereference this key while searching for a matching device. A device should not appear in the list unless probe() has succeeded and disconnect() has not finished. Cc: Oliver Neukum <oliver@neukum.org> Cc: stable <stable@vger.kernel.org> Signed-off-by: Bjørn Mork <bjorn@mork.no> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/class')
-rw-r--r--drivers/usb/class/cdc-wdm.c12
1 files changed, 9 insertions, 3 deletions
diff --git a/drivers/usb/class/cdc-wdm.c b/drivers/usb/class/cdc-wdm.c
index 90bc916d7cbd..631bb952d0f6 100644
--- a/drivers/usb/class/cdc-wdm.c
+++ b/drivers/usb/class/cdc-wdm.c
@@ -309,9 +309,6 @@ static void free_urbs(struct wdm_device *desc)
static void cleanup(struct wdm_device *desc)
{
- spin_lock(&wdm_device_list_lock);
- list_del(&desc->device_list);
- spin_unlock(&wdm_device_list_lock);
kfree(desc->sbuf);
kfree(desc->inbuf);
kfree(desc->orq);
@@ -782,6 +779,9 @@ static int wdm_create(struct usb_interface *intf, struct usb_endpoint_descriptor
out:
return rv;
err:
+ spin_lock(&wdm_device_list_lock);
+ list_del(&desc->device_list);
+ spin_unlock(&wdm_device_list_lock);
cleanup(desc);
return rv;
}
@@ -907,6 +907,12 @@ static void wdm_disconnect(struct usb_interface *intf)
cancel_work_sync(&desc->rxwork);
mutex_unlock(&desc->wlock);
mutex_unlock(&desc->rlock);
+
+ /* the desc->intf pointer used as list key is now invalid */
+ spin_lock(&wdm_device_list_lock);
+ list_del(&desc->device_list);
+ spin_unlock(&wdm_device_list_lock);
+
if (!desc->count)
cleanup(desc);
else