[PATCH 5.4 216/320] dm space map common: add bounds check to sm_ll_lookup_bitmap()

Greg Kroah-Hartman
2022-01-24T19:40:57Z

From: Joe Thornber <ejt@redhat.com>

[ Upstream commit cba23ac158db7f3cd48a923d6861bee2eb7a2978 ]

Corrupted metadata could warrant returning error from sm_ll_lookup_bitmap().

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/md/persistent-data/dm-space-map-common.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/drivers/md/persistent-data/dm-space-map-common.c b/drivers/md/persistent-data/dm-space-map-common.c
index a213bf11738fb..85853ab629717 100644
--- a/drivers/md/persistent-data/dm-space-map-common.c
+++ b/drivers/md/persistent-data/dm-space-map-common.c
@@ -281,6 +281,11 @@ 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)
--
2.34.1