From 9cdabcb3ef8c24ca3a456e4db7b012befb688e73 Mon Sep 17 00:00:00 2001 From: Oliver Neukum Date: Thu, 17 Sep 2020 12:34:27 +0200 Subject: [PATCH] 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 Reported-by: syzbot+be5b5f86a162a6c281e6@syzkaller.appspotmail.com Link: https://lore.kernel.org/r/20200917103427.15740-1-oneukum@suse.com Cc: stable Signed-off-by: Greg Kroah-Hartman --- 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);