Commit d73ae146 authored Nov 05, 2021 by Vineeth Vijayan Committed by Greg Kroah-Hartman Nov 26, 2021

s390/cio: check the subchannel validity for dev_busid



commit a4751f157c194431fae9e9c493f456df8272b871 upstream.

Check the validity of subchanel before reading other fields in
the schib.

Fixes: d3683c055212 ("s390/cio: add dev_busid sysfs entry for each subchannel")
CC: <stable@vger.kernel.org>
Reported-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Vineeth Vijayan <vneethv@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Link: https://lore.kernel.org/r/20211105154451.847288-1-vneethv@linux.ibm.com


Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 1711b877

drivers/s390/cio/css.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -371,8 +371,8 @@ static ssize_t dev_busid_show(struct device *dev,
		struct subchannel *sch = to_subchannel(dev);
		struct pmcw *pmcw = &sch->schib.pmcw;

		if ((pmcw->st == SUBCHANNEL_TYPE_IO \|\|
		pmcw->st == SUBCHANNEL_TYPE_MSG) && pmcw->dnv)
		if ((pmcw->st == SUBCHANNEL_TYPE_IO && pmcw->dnv) \|\|
		(pmcw->st == SUBCHANNEL_TYPE_MSG && pmcw->w))
		return sysfs_emit(buf, "0.%x.%04x\n", sch->schid.ssid,
		pmcw->dev);
		else