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 <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Mon Nov 6 10:22:56 CET 2017 From: Stefan Haberland <sth@xxxxxxxxxxxxxxxxxx> Date: Sat, 7 Oct 2017 22:37:49 +0000 Subject: s390/dasd: check for device error pointer within state change interrupts From: Stefan Haberland <sth@xxxxxxxxxxxxxxxxxx> [ 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. Signed-off-by: Stefan Haberland <sth@xxxxxxxxxxxxxxxxxx> Signed-off-by: Martin Schwidefsky <schwidefsky@xxxxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/s390/block/dasd.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) --- a/drivers/s390/block/dasd.c +++ b/drivers/s390/block/dasd.c @@ -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 sth@xxxxxxxxxxxxxxxxxx are queue-4.4/s390-dasd-check-for-device-error-pointer-within-state-change-interrupts.patch