Patch "libnvdimm, namespace: fix label initialization to use valid seq numbers" has been added to the 4.9-stable tree

Patch "libnvdimm, namespace: fix label initialization to use valid seq numbers" has been added to the 4.9-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    libnvdimm, namespace: fix label initialization to use valid seq numbers

to the 4.9-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     libnvdimm-namespace-fix-label-initialization-to-use-valid-seq-numbers.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From b18d4b8a25af6fe83d7692191d6ff962ea611c4f Mon Sep 17 00:00:00 2001
From: Dan Williams <dan.j.williams@intel.com>
Date: Tue, 26 Sep 2017 11:41:28 -0700
Subject: libnvdimm, namespace: fix label initialization to use valid seq numbers

From: Dan Williams <dan.j.williams@intel.com>

commit b18d4b8a25af6fe83d7692191d6ff962ea611c4f upstream.

The set of valid sequence numbers is {1,2,3}. The specification
indicates that an implementation should consider 0 a sign of a critical
error:

    UEFI 2.7: 13.19 NVDIMM Label Protocol

    Software never writes the sequence number 00, so a correctly
    check-summed Index Block with this sequence number probably indicates a
    critical error. When software discovers this case it treats it as an
    invalid Index Block indication.

While the expectation is that the invalid block is just thrown away, the
Robustness Principle says we should fix this to make both sequence
numbers valid.

Fixes: f524bf271a5c ("libnvdimm: write pmem label set")
Reported-by: Juston Li <juston.li@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/nvdimm/label.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/nvdimm/label.c
+++ b/drivers/nvdimm/label.c
@@ -861,7 +861,7 @@ static int init_labels(struct nd_mapping
 	nsindex = to_namespace_index(ndd, 0);
 	memset(nsindex, 0, ndd->nsarea.config_size);
 	for (i = 0; i < 2; i++) {
-		int rc = nd_label_write_index(ndd, i, i*2, ND_NSINDEX_INIT);
+		int rc = nd_label_write_index(ndd, i, 3 - i, ND_NSINDEX_INIT);
 
 		if (rc)
 			return rc;


Patches currently in stable-queue which might be from dan.j.williams@intel.com are

queue-4.9/libnvdimm-pfn-make-resource-attribute-only-readable-by-root.patch
queue-4.9/libnvdimm-namespace-make-resource-attribute-only-readable-by-root.patch
queue-4.9/libnvdimm-namespace-fix-label-initialization-to-use-valid-seq-numbers.patch