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authorAlexey Khoroshilov <khoroshilov@ispras.ru>2014-04-12 02:10:45 +0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-04-16 13:56:08 -0700
commit070c0b17f6a1ba39dff9be112218127e7e8fd456 (patch)
tree234e8b760c190f6a93a8f8de0776aaf2e93f5cd0
parentf9076e28013e448ba2a905ae905ac9b53f8a2e16 (diff)
USB: cdc-acm: fix double usb_autopm_put_interface() in acm_port_activate()
If acm_submit_read_urbs() fails in acm_port_activate(), error handling code calls usb_autopm_put_interface() while it is already called before acm_submit_read_urbs(). The patch reorganizes error handling code to avoid double decrement of USB interface's PM-usage counter. Found by Linux Driver Verification project (linuxtesting.org). Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru> Acked-by: Oliver Neukum <oliver@neukum.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/usb/class/cdc-acm.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index 900f7ff..d5d2c92 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -518,13 +518,16 @@ static int acm_port_activate(struct tty_port *port, struct tty_struct *tty)
if (usb_submit_urb(acm->ctrlurb, GFP_KERNEL)) {
dev_err(&acm->control->dev,
"%s - usb_submit_urb(ctrl irq) failed\n", __func__);
+ usb_autopm_put_interface(acm->control);
goto error_submit_urb;
}
acm->ctrlout = ACM_CTRL_DTR | ACM_CTRL_RTS;
if (acm_set_control(acm, acm->ctrlout) < 0 &&
- (acm->ctrl_caps & USB_CDC_CAP_LINE))
+ (acm->ctrl_caps & USB_CDC_CAP_LINE)) {
+ usb_autopm_put_interface(acm->control);
goto error_set_control;
+ }
usb_autopm_put_interface(acm->control);
@@ -549,7 +552,6 @@ error_submit_read_urbs:
error_set_control:
usb_kill_urb(acm->ctrlurb);
error_submit_urb:
- usb_autopm_put_interface(acm->control);
error_get_interface:
disconnected:
mutex_unlock(&acm->mutex);