From: Yufen Yu <[email protected]>
commit ee37e62191a59d253fc916b9fc763deb777211e2 upstream.
When doing re-add, we need to ensure rdev->mddev->pers is not NULL,
which can avoid potential NULL pointer derefence in fallowing
add_bound_rdev().
Fixes: a6da4ef85cef ("md: re-add a failed disk")
Cc: Xiao Ni <[email protected]>
Cc: NeilBrown <[email protected]>
Cc: <[email protected]> # 4.4+
Reviewed-by: NeilBrown <[email protected]>
Signed-off-by: Yufen Yu <[email protected]>
Signed-off-by: Song Liu <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
drivers/md/md.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -2845,8 +2845,10 @@ state_store(struct md_rdev *rdev, const
err = 0;
}
} else if (cmd_match(buf, "re-add")) {
- if (test_bit(Faulty, &rdev->flags) && (rdev->raid_disk == -1) &&
- rdev->saved_raid_disk >= 0) {
+ if (!rdev->mddev->pers)
+ err = -EINVAL;
+ else if (test_bit(Faulty, &rdev->flags) && (rdev->raid_disk ==
-1) &&
+ rdev->saved_raid_disk >= 0) {
/* clear_bit is performed _after_ all the devices
* have their local Faulty bit cleared. If any writes
* happen in the meantime in the local node, they
