read() needs to check whether the device has been
disconnected before it tries to talk to the device.
Signed-off-by: Oliver Neukum <oneukum@xxxxxxxx>
Reported-by: syzbot+be5b5f86a162a6c281e6@xxxxxxxxxxxxxxxxxxxxxxxxx
---
drivers/usb/class/usblp.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/drivers/usb/class/usblp.c b/drivers/usb/class/usblp.c
index 084c48c5848f..67cbd42421be 100644
--- a/drivers/usb/class/usblp.c
+++ b/drivers/usb/class/usblp.c
@@ -827,6 +827,11 @@ static ssize_t usblp_read(struct file *file, char __user *buffer, size_t len, lo
if (rv < 0)
return rv;
+ if (!usblp->present) {
+ count = -ENODEV;
+ goto done;
+ }
+
if ((avail = usblp->rstatus) < 0) {
printk(KERN_ERR "usblp%d: error %d reading from printer\n",
usblp->minor, (int)avail);
--
2.16.4
