From: Oliver Neukum oneukum@suse.com
commit 9cdabcb3ef8c24ca3a456e4db7b012befb688e73 upstream.
read() needs to check whether the device has been disconnected before it tries to talk to the device.
Signed-off-by: Oliver Neukum oneukum@suse.com Reported-by: syzbot+be5b5f86a162a6c281e6@syzkaller.appspotmail.com Link: https://lore.kernel.org/r/20200917103427.15740-1-oneukum@suse.com Cc: stable stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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 419804c9c974..db36a796af8c 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);