diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c index fe9b392bffee..39203f2ce6a1 100644 --- a/drivers/usb/core/hcd.c +++ b/drivers/usb/core/hcd.c @@ -1567,6 +1567,13 @@ int usb_hcd_submit_urb (struct urb *urb, gfp_t mem_flags) urb->hcpriv = NULL; INIT_LIST_HEAD(&urb->urb_list); atomic_dec(&urb->use_count); + /* + * Order the write of urb->use_count above before the read + * of urb->reject below. Pairs with the memory barriers in + * usb_kill_urb() and usb_poison_urb(). + */ + smp_mb__after_atomic(); + atomic_dec(&urb->dev->urbnum); if (atomic_read(&urb->reject)) wake_up(&usb_kill_urb_queue); @@ -1662,6 +1669,13 @@ static void __usb_hcd_giveback_urb(struct urb *urb) usb_anchor_resume_wakeups(anchor); atomic_dec(&urb->use_count); + /* + * Order the write of urb->use_count above before the read + * of urb->reject below. Pairs with the memory barriers in + * usb_kill_urb() and usb_poison_urb(). + */ + smp_mb__after_atomic(); + if (unlikely(atomic_read(&urb->reject))) wake_up(&usb_kill_urb_queue); usb_put_urb(urb); diff --git a/drivers/usb/core/urb.c b/drivers/usb/core/urb.c index 31ca5abb4c12..0045bbc3627d 100644 --- a/drivers/usb/core/urb.c +++ b/drivers/usb/core/urb.c @@ -691,6 +691,12 @@ void usb_kill_urb(struct urb *urb) if (!(urb && urb->dev && urb->ep)) return; atomic_inc(&urb->reject); + /* + * Order the write of urb->reject above before the read + * of urb->use_count below. Pairs with the barriers in + * __usb_hcd_giveback_urb() and usb_hcd_submit_urb(). + */ + smp_mb__after_atomic(); usb_hcd_unlink_urb(urb, -ENOENT); wait_event(usb_kill_urb_queue, atomic_read(&urb->use_count) == 0); @@ -732,6 +738,12 @@ void usb_poison_urb(struct urb *urb) if (!urb) return; atomic_inc(&urb->reject); + /* + * Order the write of urb->reject above before the read + * of urb->use_count below. Pairs with the barriers in + * __usb_hcd_giveback_urb() and usb_hcd_submit_urb(). + */ + smp_mb__after_atomic(); if (!urb->dev || !urb->ep) return;