From 4b7a35866b0ca4205ec5bacd2a5531caf19a463f Mon Sep 17 00:00:00 2001 From: Stefan Haberland Date: Sat, 7 Oct 2017 22:37:49 +0000 Subject: [PATCH] s390/dasd: check for device error pointer within state change interrupts [ 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 Signed-off-by: Martin Schwidefsky Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/s390/block/dasd.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c index 84c13dffa3a8..e7a6f1222642 100644 --- a/drivers/s390/block/dasd.c +++ b/drivers/s390/block/dasd.c @@ -1635,8 +1635,11 @@ void dasd_int_handler(struct ccw_device *cdev, unsigned long intparm, /* 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)