usb: yurex: Fix inconsistent locking bug in yurex_read()

commit e7d3b9f28654dbfce7e09f8028210489adaf6a33 upstream.

Unlock before returning on the error path.

Fixes: 86b20af11e84 ("usb: yurex: Replace snprintf() with the safer scnprintf() variant")
Reported-by: Dan Carpenter <error27@gmail.com>
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/r/202312170252.3udgrIcP-lkp@intel.com/
Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
Link: https://lore.kernel.org/r/20231219063639.450994-1-harshit.m.mogalapalli@oracle.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/misc/yurex.c b/drivers/usb/misc/yurex.c
index 494db0178c1e1dc82136bd164d4da5db392087a5..4eb30089dddf9b663fd5aabac5940a33ecff60eb 100644 (file)
--- a/drivers/usb/misc/yurex.c
+++ b/drivers/usb/misc/yurex.c
@@ -412,8 +412,10 @@ static ssize_t yurex_read(struct file *file, char __user *buffer, size_t count,
                return -ENODEV;
        }
 
-       if (WARN_ON_ONCE(dev->bbu > S64_MAX || dev->bbu < S64_MIN))
+       if (WARN_ON_ONCE(dev->bbu > S64_MAX || dev->bbu < S64_MIN)) {
+               mutex_unlock(&dev->io_mutex);
                return -EIO;
+       }
 
        spin_lock_irq(&dev->lock);
        scnprintf(in_buffer, MAX_S64_STRLEN, "%lld\n", dev->bbu);