USB: fix usb open suspend race in cdc-acm
this fixes a race between open and disconnect in the CDC ACM driver.
Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index bcc42136..0147ea3 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -496,13 +496,10 @@
otherwise it is scheduled, and with high data rates data can get lost. */
tty->low_latency = 1;
- if (usb_autopm_get_interface(acm->control)) {
- mutex_unlock(&open_mutex);
- return -EIO;
- }
+ if (usb_autopm_get_interface(acm->control) < 0)
+ goto early_bail;
mutex_lock(&acm->mutex);
- mutex_unlock(&open_mutex);
if (acm->used++) {
usb_autopm_put_interface(acm->control);
goto done;
@@ -536,6 +533,7 @@
done:
err_out:
mutex_unlock(&acm->mutex);
+ mutex_unlock(&open_mutex);
return rv;
full_bailout:
@@ -544,6 +542,8 @@
usb_autopm_put_interface(acm->control);
acm->used--;
mutex_unlock(&acm->mutex);
+early_bail:
+ mutex_unlock(&open_mutex);
return -EIO;
}