From: Oliver Neukum <oneukum@xxxxxxxx> 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@xxxxxxxx> Reported-by: syzbot+be5b5f86a162a6c281e6@xxxxxxxxxxxxxxxxxxxxxxxxx Link: https://lore.kernel.org/r/20200917103427.15740-1-oneukum@xxxxxxxx Cc: stable <stable@xxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/usb/class/usblp.c | 5 +++++ 1 file changed, 5 insertions(+) --- a/drivers/usb/class/usblp.c +++ b/drivers/usb/class/usblp.c @@ -840,6 +840,11 @@ static ssize_t usblp_read(struct file *f 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);
