From: Daniel Wagner <dwagner@suse.de>
Date: Mon, 7 Jun 2021 10:56:56 +0200
Subject: nvme: verify MNAN value if ANA is enabled
Patch-mainline: v5.14-rc1
Git-commit: 120bb3624d55d65145f7c1bf12a839fd323cde29
References: bsc#1185791

The controller is required to have a non-zero MNAN value if it supports
ANA:

   If the controller supports Asymmetric Namespace Access Reporting, then
   this field shall be set to a non-zero value that is less than or equal
   to the NN value.

Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/nvme/host/multipath.c |    7 +++++++
 1 file changed, 7 insertions(+)

--- a/drivers/nvme/host/multipath.c
+++ b/drivers/nvme/host/multipath.c
@@ -730,6 +730,13 @@ int nvme_mpath_init(struct nvme_ctrl *ct
 	if (!multipath || !ctrl->subsys || !(ctrl->subsys->cmic & (1 << 3)))
 		return 0;
 
+	if (!ctrl->max_namespaces ||
+	    ctrl->max_namespaces > le32_to_cpu(id->nn)) {
+		dev_err(ctrl->device,
+			"Invalid MNAN value %u\n", ctrl->max_namespaces);
+		return -EINVAL;
+	}
+
 	ctrl->anacap = id->anacap;
 	ctrl->anatt = id->anatt;
 	ctrl->nanagrpid = le32_to_cpu(id->nanagrpid);