+ maple_tree-fix-mas_prev-and-mas_find-state-handling.patch added to mm-unstable branch

+ maple_tree-fix-mas_prev-and-mas_find-state-handling.patch added to mm-unstable branch

[Andrew Morton]

The patch titled
     Subject: maple_tree: fix mas_prev() and mas_find() state handling
has been added to the -mm mm-unstable branch.  Its filename is
     maple_tree-fix-mas_prev-and-mas_find-state-handling.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-mas_prev-and-mas_find-state-handling.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 R. Howlett" <Liam.Howlett@oracle.com>
Subject: maple_tree: fix mas_prev() and mas_find() state handling
Date: Fri, 20 Jan 2023 11:26:07 -0500

When mas_prev() does not find anything, set the state to MAS_NONE.

Handle the MAS_NONE in mas_find() like a MAS_START.

Link: https://lkml.kernel.org/r/20230120162650.984577-7-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reported-by: <syzbot+502859d610c661e56545@syzkaller.appspotmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---


--- a/lib/maple_tree.c~maple_tree-fix-mas_prev-and-mas_find-state-handling
+++ a/lib/maple_tree.c
@@ -4844,7 +4844,7 @@ static inline void *mas_prev_entry(struc
 
 	if (mas->index < min) {
 		mas->index = mas->last = min;
-		mas_pause(mas);
+		mas->node = MAS_NONE;
 		return NULL;
 	}
 retry:
@@ -5918,6 +5918,7 @@ void *mas_prev(struct ma_state *mas, uns
 	if (!mas->index) {
 		/* Nothing comes before 0 */
 		mas->last = 0;
+		mas->node = MAS_NONE;
 		return NULL;
 	}
 
@@ -6008,6 +6009,9 @@ void *mas_find(struct ma_state *mas, uns
 		mas->index = ++mas->last;
 	}
 
+	if (unlikely(mas_is_none(mas)))
+		mas->node = MAS_START;
+
 	if (unlikely(mas_is_start(mas))) {
 		/* First run or continue */
 		void *entry;
_

Patches currently in -mm which might be from Liam.Howlett@oracle.com are

maple_tree-fix-handle-of-invalidated-state-in-mas_wr_store_setup.patch
maple_tree-fix-mas_prev-and-mas_find-state-handling.patch
nommu-pass-through-vma-iterator-to-shrink_vma.patch
mm-damon-vaddr-testh-stop-using-vma_mas_store-for-maple-tree-store.patch
mm-mremap-convert-vma_adjust-to-vma_expand.patch