[dm-devel] Patch "dm space map common: add bounds check to sm_ll_lookup_bitmap()" has been added to the 4.19-stable tree

[Sasha Levin]

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

    dm space map common: add bounds check to sm_ll_lookup_bitmap()

to the 4.19-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-space-map-common-add-bounds-check-to-sm_ll_lookup.patch
and it can be found in the queue-4.19 subdirectory.

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



commit faf4e42dba37be3b4d94c54064ce021d8c7d8f9a
Author: Joe Thornber <ejt at redhat.com>
Date:   Fri Dec 10 13:49:53 2021 +0000

    dm space map common: add bounds check to sm_ll_lookup_bitmap()
    
    [ Upstream commit cba23ac158db7f3cd48a923d6861bee2eb7a2978 ]
    
    Corrupted metadata could warrant returning error from sm_ll_lookup_bitmap().
    
    Signed-off-by: Joe Thornber <ejt at redhat.com>
    Signed-off-by: Mike Snitzer <snitzer at redhat.com>
    Signed-off-by: Sasha Levin <sashal at kernel.org>

diff --git a/drivers/md/persistent-data/dm-space-map-common.c b/drivers/md/persistent-data/dm-space-map-common.c
index a284762e548e1..5115a27196038 100644
--- a/drivers/md/persistent-data/dm-space-map-common.c
+++ b/drivers/md/persistent-data/dm-space-map-common.c
@@ -279,6 +279,11 @@ int sm_ll_lookup_bitmap(struct ll_disk *ll, dm_block_t b, uint32_t *result)
 	struct disk_index_entry ie_disk;
 	struct dm_block *blk;
 
+	if (b >= ll->nr_blocks) {
+		DMERR_LIMIT("metadata block out of bounds");
+		return -EINVAL;
+	}
+
 	b = do_div(index, ll->entries_per_block);
 	r = ll->load_ie(ll, index, &ie_disk);
 	if (r < 0)