+ maple_tree-fix-mt_destroy_walk-on-root-leaf-node.patch added to mm-hotfixes-unstable branch

+ maple_tree-fix-mt_destroy_walk-on-root-leaf-node.patch added to mm-hotfixes-unstable branch

[Andrew Morton]

The patch titled
     Subject: maple_tree: fix mt_destroy_walk() on root leaf node
has been added to the -mm mm-hotfixes-unstable branch.  Its filename is
     maple_tree-fix-mt_destroy_walk-on-root-leaf-node.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/maple_tree-fix-mt_destroy_walk-on-root-leaf-node.patch

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

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------------------------------------------------------
From: Wei Yang <richard.weiyang@gmail.com>
Subject: maple_tree: fix mt_destroy_walk() on root leaf node
Date: Tue, 24 Jun 2025 15:18:40 -0400

On destroy, we should set each node dead.  But current code miss this when
the maple tree has only the root node.

The reason is mt_destroy_walk() leverage mte_destroy_descend() to set node
dead, but this is skipped since the only root node is a leaf.

Fixes this by setting the node dead if it is a leaf.

Link: https://lore.kernel.org/all/20250407231354.11771-1-richard.weiyang@gmail.com/
Link: https://lkml.kernel.org/r/20250624191841.64682-1-Liam.Howlett@oracle.com
Fixes: 54a611b60590 ("Maple Tree: add new data structure")
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 lib/maple_tree.c |    1 +
 1 file changed, 1 insertion(+)

--- a/lib/maple_tree.c~maple_tree-fix-mt_destroy_walk-on-root-leaf-node
+++ a/lib/maple_tree.c
@@ -5319,6 +5319,7 @@ static void mt_destroy_walk(struct maple
 	struct maple_enode *start;
 
 	if (mte_is_leaf(enode)) {
+		mte_set_node_dead(enode);
 		node->type = mte_node_type(enode);
 		goto free_leaf;
 	}
_

Patches currently in -mm which might be from richard.weiyang@gmail.com are

maple_tree-fix-mt_destroy_walk-on-root-leaf-node.patch
maple_tree-assert-retrieving-new-value-on-a-tree-containing-just-a-leaf-node.patch