Patch "s390/dasd: check for device error pointer within state change interrupts" has been added to the 4.4-stable tree

This is a note to let you know that I've just added the patch titled

s390/dasd: check for device error pointer within state change interrupts

to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
s390-dasd-check-for-device-error-pointer-within-state-change-interrupts.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Stefan Haberland <[email protected]>
Date: Sat, 7 Oct 2017 22:37:49 +0000
Subject: s390/dasd: check for device error pointer within state change interrupts

From: Stefan Haberland <[email protected]>

[ Upstream commit 2202134e48a3b50320aeb9e3dd1186833e9d7e66 ]

Check if the device pointer is valid. Just a sanity check since we already are in the int handler of the device.

---
 drivers/s390/block/dasd.c |    7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

@@ -1635,8 +1635,11 @@ void dasd_int_handler(struct ccw_device
 	/* check for for attention message */
 	if (scsw_dstat(&irb->scsw) & DEV_STAT_ATTENTION) {
 		device = dasd_device_from_cdev_locked(cdev);
-		device->discipline->check_attention(device, irb->esw.esw1.lpum);
-		dasd_put_device(device);
+		if (!IS_ERR(device)) {
+			device->discipline->check_attention(device,
+							    irb->esw.esw1.lpum);
+			dasd_put_device(device);
+		}
 	}
 
 	if (!cqr)

Patches currently in stable-queue which might be from [email protected] are

queue-4.4/s390-dasd-check-for-device-error-pointer-within-state-change-interrupts.patch