From: Vineeth Vijayan vneethv@linux.ibm.com
commit dd9cb842fa9d90653a9b48aba52f89c069f3bc50 upstream.
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/s390/cio/device.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/s390/cio/device.c +++ b/drivers/s390/cio/device.c @@ -1194,7 +1194,7 @@ static int io_subchannel_chp_event(struc else path_event[chpid] = PE_NONE; } - if (cdev) + if (cdev && cdev->drv && cdev->drv->path_event) cdev->drv->path_event(cdev, path_event); break; }