diff options
| author | Oliver Neukum <oliver@neukum.org> | 2008-03-31 16:27:30 +0200 |
|---|---|---|
| committer | Jiri Kosina <jkosina@suse.cz> | 2008-04-22 11:34:58 +0200 |
| commit | 69626f23bce6521367ac1e6a2a6e8fba8f0a848a (patch) | |
| tree | 46342a02c79e0e69a1c1eed1239944c4f952b13c | |
| parent | abdff0f7749a6696ba2a4238b675cbc55abcdb7a (diff) | |
HID: fix race between open() and disconnect() in usbhid
There is a window:
task A task B
spin_lock_irq(&usbhid->inlock); /* Sync with error handler */
usb_set_intfdata(intf, NULL);
spin_unlock_irq(&usbhid->inlock);
usb_kill_urb(usbhid->urbin);
usb_kill_urb(usbhid->urbout);
usb_kill_urb(usbhid->urbctrl);
del_timer_sync(&usbhid->io_retry);
cancel_work_sync(&usbhid->reset_work);
if (!hid->open++) {
res = usb_autopm_get_interface(usbhid->intf);
if (res < 0) {
hid->open--;
return -EIO;
}
}
if (hid_start_in(hid))
if (hid->claimed & HID_CLAIMED_INPUT)
hidinput_disconnect(hid);
in which an open() to an already disconnected device will submit an URB
to an undead device. In case disconnect() was called by an ioctl, this'll
oops. Fix by introducing a new flag and checking it in hid_start_in().
Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
| -rw-r--r-- | drivers/hid/usbhid/hid-core.c | 4 | ||||
| -rw-r--r-- | include/linux/hid.h | 1 |
2 files changed, 4 insertions, 1 deletions
diff --git a/drivers/hid/usbhid/hid-core.c b/drivers/hid/usbhid/hid-core.c index f6a5d893034..e0d805f1b2b 100644 --- a/drivers/hid/usbhid/hid-core.c +++ b/drivers/hid/usbhid/hid-core.c @@ -82,6 +82,7 @@ static int hid_start_in(struct hid_device *hid) spin_lock_irqsave(&usbhid->inlock, flags); if (hid->open > 0 && !test_bit(HID_SUSPENDED, &usbhid->iofl) && + !test_bit(HID_DISCONNECTED, &usbhid->iofl) && !test_and_set_bit(HID_IN_RUNNING, &usbhid->iofl)) { rc = usb_submit_urb(usbhid->urbin, GFP_ATOMIC); if (rc != 0) @@ -155,7 +156,7 @@ static void hid_io_error(struct hid_device *hid) spin_lock_irqsave(&usbhid->inlock, flags); /* Stop when disconnected */ - if (usb_get_intfdata(usbhid->intf) == NULL) + if (test_bit(HID_DISCONNECTED, &usbhid->iofl)) goto done; /* If it has been a while since the last error, we'll assume @@ -941,6 +942,7 @@ static void hid_disconnect(struct usb_interface *intf) spin_lock_irq(&usbhid->inlock); /* Sync with error handler */ usb_set_intfdata(intf, NULL); + set_bit(HID_DISCONNECTED, &usbhid->iofl); spin_unlock_irq(&usbhid->inlock); usb_kill_urb(usbhid->urbin); usb_kill_urb(usbhid->urbout); diff --git a/include/linux/hid.h b/include/linux/hid.h index fe4ac31eced..d951ec41124 100644 --- a/include/linux/hid.h +++ b/include/linux/hid.h @@ -424,6 +424,7 @@ struct hid_control_fifo { #define HID_RESET_PENDING 4 #define HID_SUSPENDED 5 #define HID_CLEAR_HALT 6 +#define HID_DISCONNECTED 7 struct hid_input { struct list_head list; |