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authorOliver Neukum <oneukum@suse.com>2020-09-17 12:34:27 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-09-17 18:45:30 +0200
commit9cdabcb3ef8c24ca3a456e4db7b012befb688e73 (patch)
tree2c7043613f45b20b4f325f66855618056407f2b4 /drivers/usb/class
parent29231826f3bd65500118c473fccf31c0cf14dbc0 (diff)
downloadlinux-9cdabcb3ef8c24ca3a456e4db7b012befb688e73.tar.bz2
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>
Diffstat (limited to 'drivers/usb/class')
-rw-r--r--drivers/usb/class/usblp.c5
1 files changed, 5 insertions, 0 deletions
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);