From dd9cb842fa9d90653a9b48aba52f89c069f3bc50 Mon Sep 17 00:00:00 2001
From: Vineeth Vijayan <vneethv@linux.ibm.com>
Date: Wed, 2 Feb 2022 21:45:56 +0100
Subject: [PATCH] s390/cio: verify the driver availability for path_event call
If no driver is attached to a device or the driver does not provide the
path_event function, an FCES path-event on this device could end up in a
kernel-panic. Verify the driver availability before the path_event
function call.
Fixes: 32ef938815c1 ("s390/cio: Add support for FCES status notification")
Cc: stable@vger.kernel.org
Signed-off-by: Vineeth Vijayan <vneethv@linux.ibm.com>
Suggested-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Reviewed-by: Jan Hoeppner <hoeppner@linux.ibm.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
---
drivers/s390/cio/device.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
index cd938a26b76c2..3b1cd0c96a74b 100644
--- a/drivers/s390/cio/device.c
+++ b/drivers/s390/cio/device.c
@@ -1180,7 +1180,7 @@ static int io_subchannel_chp_event(struct subchannel *sch,
else
path_event[chpid] = PE_NONE;
}
- if (cdev)
+ if (cdev && cdev->drv && cdev->drv->path_event)
cdev->drv->path_event(cdev, path_event);
break;
}
--
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