drivers/net/usb/catc.c: Fix potential deadlock in catc_ctrl_run()

khoroshilov · davem330 · commit 930a6eac9f40 · 2011-05-31T15:30:17.000-07:00
catc_ctrl_run() calls usb_submit_urb() with GFP_KERNEL, while it is called from
catc_ctrl_async() and catc_ctrl_done() with catc-&gt;ctrl_lock spinlock held.

The patch replaces GFP_KERNEL with GFP_ATOMIC.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov &lt;khoroshilov@ispras.ru&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
diff --git a/drivers/net/usb/catc.c b/drivers/net/usb/catc.c
@@ -495,7 +495,7 @@ static void catc_ctrl_run(struct catc *catc)
 	if (!q->dir && q->buf && q->len)
 		memcpy(catc->ctrl_buf, q->buf, q->len);
 
-	if ((status = usb_submit_urb(catc->ctrl_urb, GFP_KERNEL)))
+	if ((status = usb_submit_urb(catc->ctrl_urb, GFP_ATOMIC)))
 		err("submit(ctrl_urb) status %d", status);
 }
 

Original file line number	Diff line number	Diff line change
`@@ -495,7 +495,7 @@ static void catc_ctrl_run(struct catc *catc)`
`495`	`495`	`if (!q->dir && q->buf && q->len)`
`496`	`496`	`memcpy(catc->ctrl_buf, q->buf, q->len);`
`497`	`497`
`498`		`- if ((status = usb_submit_urb(catc->ctrl_urb, GFP_KERNEL)))`
	`498`	`+ if ((status = usb_submit_urb(catc->ctrl_urb, GFP_ATOMIC)))`
`499`	`499`	`err("submit(ctrl_urb) status %d", status);`
`500`	`500`	`}`
`501`	`501`