linux-kernel - [PATCH v2 4/4] media: stkwebcam: fix runtime PM after driver unbind

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20191001084908.2003-5-johan@kernel.org>
Date:   Tue,  1 Oct 2019 10:49:08 +0200
From:   Johan Hovold <johan@...nel.org>
To:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Mauro Carvalho Chehab <mchehab@...nel.org>
Cc:     Pete Zaitcev <zaitcev@...hat.com>,
        Alan Stern <stern@...land.harvard.edu>,
        linux-media@...r.kernel.org, linux-usb@...r.kernel.org,
        linux-kernel@...r.kernel.org, Johan Hovold <johan@...nel.org>,
        stable <stable@...r.kernel.org>,
        Mauro Carvalho Chehab <mchehab+samsung@...nel.org>
Subject: [PATCH v2 4/4] media: stkwebcam: fix runtime PM after driver unbind

Since commit c2b71462d294 ("USB: core: Fix bug caused by duplicate
interface PM usage counter") USB drivers must always balance their
runtime PM gets and puts, including when the driver has already been
unbound from the interface.

Leaving the interface with a positive PM usage counter would prevent a
later bound driver from suspending the device.

Note that runtime PM has never actually been enabled for this driver
since the support_autosuspend flag in its usb_driver struct is not set.

Fixes: c2b71462d294 ("USB: core: Fix bug caused by duplicate interface PM usage counter")
Cc: stable <stable@...r.kernel.org>
Acked-by: Mauro Carvalho Chehab <mchehab+samsung@...nel.org>
Signed-off-by: Johan Hovold <johan@...nel.org>
---
 drivers/media/usb/stkwebcam/stk-webcam.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/media/usb/stkwebcam/stk-webcam.c b/drivers/media/usb/stkwebcam/stk-webcam.c
index be8041e3e6b8..b0cfa4c1f8cc 100644
--- a/drivers/media/usb/stkwebcam/stk-webcam.c
+++ b/drivers/media/usb/stkwebcam/stk-webcam.c
@@ -643,8 +643,7 @@ static int v4l_stk_release(struct file *fp)
 		dev->owner = NULL;
 	}
 
-	if (is_present(dev))
-		usb_autopm_put_interface(dev->interface);
+	usb_autopm_put_interface(dev->interface);
 	mutex_unlock(&dev->lock);
 	return v4l2_fh_release(fp);
 }
-- 
2.23.0