From: Vineeth Vijayan <vneethv@linux.ibm.com> stable inclusion from stable-5.10.80 commit 1174298a5b31ba566a4dee424230c10673014ea7 bugzilla: 185821 https://gitee.com/openeuler/kernel/issues/I4L7CG Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- 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> Signed-off-by: Chen Jun <chenjun102@huawei.com> Reviewed-by: Weilong Chen <chenweilong@huawei.com> Acked-by: Weilong Chen <chenweilong@huawei.com> Signed-off-by: Chen Jun <chenjun102@huawei.com> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> --- drivers/s390/cio/css.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/s390/cio/css.c b/drivers/s390/cio/css.c index 305db4173dcf..cf2c3c4c590f 100644 --- a/drivers/s390/cio/css.c +++ b/drivers/s390/cio/css.c @@ -433,8 +433,8 @@ 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 -- 2.20.1