Commit 9cdabcb3 authored Sep 17, 2020 by Oliver Neukum Committed by Greg Kroah-Hartman Sep 17, 2020

usblp: fix race between disconnect() and read()



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>

parent 29231826

drivers/usb/class/usblp.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -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);

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