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| author | Oliver Neukum <oneukum@suse.com> | 2020-09-17 12:34:27 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-09-17 18:45:30 +0200 |
| commit | 9cdabcb3ef8c24ca3a456e4db7b012befb688e73 (patch) | |
| tree | 2c7043613f45b20b4f325f66855618056407f2b4 | |
| parent | 29231826f3bd65500118c473fccf31c0cf14dbc0 (diff) | |
| download | linux-9cdabcb3ef8c24ca3a456e4db7b012befb688e73.tar.gz linux-9cdabcb3ef8c24ca3a456e4db7b012befb688e73.tar.bz2 linux-9cdabcb3ef8c24ca3a456e4db7b012befb688e73.zip | |
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>
| -rw-r--r-- | drivers/usb/class/usblp.c | 5 |
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); |