USB: wdm: close race between wdm_open and wdm_wwan_port_stop

commit c1846ed4eb527bdfe6b3b7dd2c78e2af4bf98f4f upstream.

Clearing WDM_WWAN_IN_USE must be the last action or
we can open a chardev whose URBs are still poisoned

Fixes: cac6fb015f ("usb: class: cdc-wdm: WWAN framework integration")
Cc: stable <stable@kernel.org>
Signed-off-by: Oliver Neukum <oneukum@suse.com>
Link: https://lore.kernel.org/r/20250401084749.175246-3-oneukum@suse.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Oliver Neukum
2025-04-01 10:45:39 +02:00
committed by Greg Kroah-Hartman
parent 8312053acc
commit 54f7f8978a

View File

@@ -726,7 +726,7 @@ static int wdm_open(struct inode *inode, struct file *file)
rv = -EBUSY;
goto out;
}
smp_rmb(); /* ordered against wdm_wwan_port_stop() */
rv = usb_autopm_get_interface(desc->intf);
if (rv < 0) {
dev_err(&desc->intf->dev, "Error autopm - %d\n", rv);
@@ -868,8 +868,10 @@ static void wdm_wwan_port_stop(struct wwan_port *port)
poison_urbs(desc);
desc->manage_power(desc->intf, 0);
clear_bit(WDM_READ, &desc->flags);
clear_bit(WDM_WWAN_IN_USE, &desc->flags);
unpoison_urbs(desc);
smp_wmb(); /* ordered against wdm_open() */
/* this must be last lest we open a poisoned device */
clear_bit(WDM_WWAN_IN_USE, &desc->flags);
}
static void wdm_wwan_port_tx_complete(struct urb *urb)