4.18-stable review patch. If anyone has any objections, please let me know.
------------------
From: Joe Thornber <ejt@xxxxxxxxxx>
commit 4561ffca88c546f96367f94b8f1e4715a9c62314 upstream.
Commit fd2fa9541 ("dm cache metadata: save in-core policy_hint_size to
on-disk superblock") enabled previously written policy hints to be
used after a cache is reactivated. But in doing so the cache
metadata's hint array was left exposed to out of bounds access because
on resize the metadata's on-disk hint array wasn't ever extended.
Fix this by ignoring that there are no on-disk hints associated with the
newly added cache blocks. An expanded on-disk hint array is later
rewritten upon the next clean shutdown of the cache.
Fixes: fd2fa9541 ("dm cache metadata: save in-core policy_hint_size to on-disk superblock")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Joe Thornber <ejt@xxxxxxxxxx>
Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/md/dm-cache-metadata.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/drivers/md/dm-cache-metadata.c
+++ b/drivers/md/dm-cache-metadata.c
@@ -1455,8 +1455,8 @@ static int __load_mappings(struct dm_cac
if (hints_valid) {
r = dm_array_cursor_next(&cmd->hint_cursor);
if (r) {
- DMERR("dm_array_cursor_next for hint failed");
- goto out;
+ dm_array_cursor_end(&cmd->hint_cursor);
+ hints_valid = false;
}
}
