4.4-stable review patch. If anyone has any objections, please let me know.
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From: Jia-Ju Bai baijiaju1990@gmail.com
commit 6e22e3af7bb3a7b9dc53cb4687659f6e63fca427 upstream.
wdm_in_callback() is a completion handler function for the USB driver. So it should not sleep. But it calls service_outstanding_interrupt(), which calls usb_submit_urb() with GFP_KERNEL.
To fix this bug, GFP_KERNEL is replaced with GFP_ATOMIC.
This bug is found by my static analysis tool DSAC.
Signed-off-by: Jia-Ju Bai baijiaju1990@gmail.com Cc: stable stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/usb/class/cdc-wdm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/usb/class/cdc-wdm.c +++ b/drivers/usb/class/cdc-wdm.c @@ -453,7 +453,7 @@ static int clear_wdm_read_flag(struct wd
set_bit(WDM_RESPONDING, &desc->flags); spin_unlock_irq(&desc->iuspin); - rv = usb_submit_urb(desc->response, GFP_KERNEL); + rv = usb_submit_urb(desc->response, GFP_ATOMIC); spin_lock_irq(&desc->iuspin); if (rv) { dev_err(&desc->intf->dev,