diff mbox series

[5.10,03/80] btrfs: tree-checker: check item_size for dev_item

Message ID 20220228172312.111075326@linuxfoundation.org
State New
Headers show
Series None | expand

Commit Message

gregkh@linuxfoundation.org Feb. 28, 2022, 5:23 p.m. UTC 
From: Su Yue <l@damenly.su>

commit ea1d1ca4025ac6c075709f549f9aa036b5b6597d upstream.

Check item size before accessing the device item to avoid out of bound
access, similar to inode_item check.

Signed-off-by: Su Yue <l@damenly.su>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 fs/btrfs/tree-checker.c |    8 ++++++++
 1 file changed, 8 insertions(+)
diff mbox series

Patch

--- a/fs/btrfs/tree-checker.c
+++ b/fs/btrfs/tree-checker.c
@@ -947,6 +947,7 @@  static int check_dev_item(struct extent_
 			  struct btrfs_key *key, int slot)
 {
 	struct btrfs_dev_item *ditem;
+	const u32 item_size = btrfs_item_size_nr(leaf, slot);
 
 	if (key->objectid != BTRFS_DEV_ITEMS_OBJECTID) {
 		dev_item_err(leaf, slot,
@@ -954,6 +955,13 @@  static int check_dev_item(struct extent_
 			     key->objectid, BTRFS_DEV_ITEMS_OBJECTID);
 		return -EUCLEAN;
 	}
+
+	if (unlikely(item_size != sizeof(*ditem))) {
+		dev_item_err(leaf, slot, "invalid item size: has %u expect %zu",
+			     item_size, sizeof(*ditem));
+		return -EUCLEAN;
+	}
+
 	ditem = btrfs_item_ptr(leaf, slot, struct btrfs_dev_item);
 	if (btrfs_device_id(leaf, ditem) != key->offset) {
 		dev_item_err(leaf, slot,