[PATCH 4.4 008/135] usblp: poison URBs upon disconnect

[Sasha Levin]

From: Oliver Neukum <oneukum@xxxxxxxx>

[ Upstream commit 296a193b06120aa6ae7cf5c0d7b5e5b55968026e ]

syzkaller reported an URB that should have been killed to be active.
We do not understand it, but this should fix the issue if it is real.

Signed-off-by: Oliver Neukum <oneukum@xxxxxxxx>
Reported-by: syzbot+be5b5f86a162a6c281e6@xxxxxxxxxxxxxxxxxxxxxxxxx
Link: https://lore.kernel.org/r/20200507085806.5793-1-oneukum@xxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/usb/class/usblp.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/class/usblp.c b/drivers/usb/class/usblp.c
index 07c3c3449147f..c578d64edc153 100644
--- a/drivers/usb/class/usblp.c
+++ b/drivers/usb/class/usblp.c
@@ -481,7 +481,8 @@ static int usblp_release(struct inode *inode, struct file *file)
 	usb_autopm_put_interface(usblp->intf);
 
 	if (!usblp->present)		/* finish cleanup from disconnect */
-		usblp_cleanup(usblp);
+		usblp_cleanup(usblp);	/* any URBs must be dead */
+
 	mutex_unlock(&usblp_mutex);
 	return 0;
 }
@@ -1397,9 +1398,11 @@ static void usblp_disconnect(struct usb_interface *intf)
 
 	usblp_unlink_urbs(usblp);
 	mutex_unlock(&usblp->mut);
+	usb_poison_anchored_urbs(&usblp->urbs);
 
 	if (!usblp->used)
 		usblp_cleanup(usblp);
+
 	mutex_unlock(&usblp_mutex);
 }
 
-- 
2.25.1