Patch "dm integrity: test for corrupted disk format during table load" has been added to the 4.12-stable tree

[<gregkh@linuxfoundation.org>]

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

    dm integrity: test for corrupted disk format during table load

to the 4.12-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:
     dm-integrity-test-for-corrupted-disk-format-during-table-load.patch
and it can be found in the queue-4.12 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 bc86a41e96c5b6f07453c405e036d95acc673389 Mon Sep 17 00:00:00 2001
From: Mikulas Patocka <mpatocka@redhat.com>
Date: Fri, 21 Jul 2017 11:58:38 -0400
Subject: dm integrity: test for corrupted disk format during table load

From: Mikulas Patocka <mpatocka@redhat.com>

commit bc86a41e96c5b6f07453c405e036d95acc673389 upstream.

If the dm-integrity superblock was corrupted in such a way that the
journal_sections field was zero, the integrity target would deadlock
because it would wait forever for free space in the journal.

Detect this situation and refuse to activate the device.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Fixes: 7eada909bfd7 ("dm: add integrity target")
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/md/dm-integrity.c |    5 +++++
 1 file changed, 5 insertions(+)

--- a/drivers/md/dm-integrity.c
+++ b/drivers/md/dm-integrity.c
@@ -3021,6 +3021,11 @@ static int dm_integrity_ctr(struct dm_ta
 		ti->error = "Block size doesn't match the information in superblock";
 		goto bad;
 	}
+	if (!le32_to_cpu(ic->sb->journal_sections)) {
+		r = -EINVAL;
+		ti->error = "Corrupted superblock, journal_sections is 0";
+		goto bad;
+	}
 	/* make sure that ti->max_io_len doesn't overflow */
 	if (ic->sb->log2_interleave_sectors < MIN_LOG2_INTERLEAVE_SECTORS ||
 	    ic->sb->log2_interleave_sectors > MAX_LOG2_INTERLEAVE_SECTORS) {


Patches currently in stable-queue which might be from mpatocka@redhat.com are

queue-4.12/dm-integrity-fix-inefficient-allocation-of-journal-space.patch
queue-4.12/dm-integrity-test-for-corrupted-disk-format-during-table-load.patch