[PATCH 3.12 113/113] USB: cdc-acm: fix failed open not being detected

From: Jiri Slaby
Date: Mon Mar 06 2017 - 04:16:59 EST


From: Johan Hovold <jhovold@xxxxxxxxx>

3.12-stable review patch. If anyone has any objections, please let me know.

===============

commit 8727bf689a77a79816065e23a7a58a474ad544f9 upstream.

Fix errors during open not being returned to userspace. Specifically,
failed control-line manipulations or control or read urb submissions
would not be detected.

Fixes: 7fb57a019f94 ("USB: cdc-acm: Fix potential deadlock (lockdep
warning)")

Signed-off-by: Johan Hovold <jhovold@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
drivers/usb/class/cdc-acm.c | 14 ++++++++------
1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index 667f16c169d2..ea93b35b1c6d 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -514,17 +514,17 @@ static int acm_port_activate(struct tty_port *port, struct tty_struct *tty)
acm->control->needs_remote_wakeup = 1;

acm->ctrlurb->dev = acm->dev;
- if (usb_submit_urb(acm->ctrlurb, GFP_KERNEL)) {
+ retval = usb_submit_urb(acm->ctrlurb, GFP_KERNEL);
+ if (retval) {
dev_err(&acm->control->dev,
"%s - usb_submit_urb(ctrl irq) failed\n", __func__);
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)) {
+ retval = acm_set_control(acm, acm->ctrlout);
+ if (retval < 0 && (acm->ctrl_caps & USB_CDC_CAP_LINE))
goto error_set_control;
- }

/*
* Unthrottle device in case the TTY was closed while throttled.
@@ -534,7 +534,8 @@ static int acm_port_activate(struct tty_port *port, struct tty_struct *tty)
acm->throttle_req = 0;
spin_unlock_irq(&acm->read_lock);

- if (acm_submit_read_urbs(acm, GFP_KERNEL))
+ retval = acm_submit_read_urbs(acm, GFP_KERNEL);
+ if (retval)
goto error_submit_read_urbs;

usb_autopm_put_interface(acm->control);
@@ -555,7 +556,8 @@ error_submit_urb:
error_get_interface:
disconnected:
mutex_unlock(&acm->mutex);
- return retval;
+
+ return usb_translate_errors(retval);
}

static void acm_port_destruct(struct tty_port *port)
--
2.12.0