+ maple-tree-add-new-data-structure-fix-7.patch added to mm-unstable branch

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: maple_tree: fix mt_destroy_walk() on full non-leaf non-alloc nodes
has been added to the -mm mm-unstable branch.  Its filename is
     maple-tree-add-new-data-structure-fix-7.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/maple-tree-add-new-data-structure-fix-7.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Liam Howlett <liam.howlett@oracle.com>
Subject: maple_tree: fix mt_destroy_walk() on full non-leaf non-alloc nodes
Date: Wed, 15 Jun 2022 14:19:38 +0000

It is possible to iterate over the metadata of full non-leaf nodes when
operating in non-alloc mode.

Link: https://lkml.kernel.org/r/20220615141921.417598-2-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Qian Cai <quic_qiancai@quicinc.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 lib/maple_tree.c |   12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

--- a/lib/maple_tree.c~maple-tree-add-new-data-structure-fix-7
+++ a/lib/maple_tree.c
@@ -5429,11 +5429,15 @@ static void mt_destroy_walk(struct maple
 			goto start_slots_free;
 		type = mte_node_type(mas.node);
 		slots = ma_slots(mte_to_node(mas.node), type);
-		if ((offset < mt_slots[type]) && (slots[offset])) {
-			struct maple_enode *parent = mas.node;
+		if ((offset < mt_slots[type])) {
+			struct maple_enode *next = slots[offset];
 
-			mas.node = mas_slot_locked(&mas, slots, offset);
-			slots = mas_destroy_descend(&mas, parent, offset);
+			if (mte_node_type(next) && mte_to_node(next)) {
+				struct maple_enode *parent = mas.node;
+
+				mas.node = mas_slot_locked(&mas, slots, offset);
+				slots = mas_destroy_descend(&mas, parent, offset);
+			}
 		}
 		node = mas_mn(&mas);
 	} while (start != mas.node);
_

Patches currently in -mm which might be from liam.howlett@oracle.com are

maple-tree-add-new-data-structure-fix.patch
maple-tree-add-new-data-structure-fix-2.patch
maple-tree-add-new-data-structure-fix-3.patch
maple-tree-add-new-data-structure-fix-4.patch
maple-tree-add-new-data-structure-fix-7.patch
maple-tree-add-new-data-structure-fix-8.patch
lib-test_maple_tree-add-testing-for-maple-tree-fix.patch
mm-start-tracking-vmas-with-maple-tree-fix-2.patch
mm-mmap-use-advanced-maple-tree-api-for-mmap_region-fix-2.patch
mm-mmap-change-do_brk_munmap-to-use-do_mas_align_munmap-fix.patch
mm-remove-the-vma-linked-list-fix.patch