From 17dc622c7b0f94e49bed030726df4db12ecaa6b5 Mon Sep 17 00:00:00 2001
From: "Liam R. Howlett" <Liam.Howlett@oracle.com>
Date: Fri, 20 Jan 2023 11:26:07 -0500
Subject: [PATCH] maple_tree: fix mas_prev() and mas_find() state handling
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>
---
lib/maple_tree.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index 7c786bd5e575a..5e97031892590 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -4845,7 +4845,7 @@ static inline void *mas_prev_entry(struct ma_state *mas, unsigned long min)
if (mas->index < min) {
mas->index = mas->last = min;
- mas_pause(mas);
+ mas->node = MAS_NONE;
return NULL;
}
retry:
@@ -5919,6 +5919,7 @@ void *mas_prev(struct ma_state *mas, unsigned long min)
if (!mas->index) {
/* Nothing comes before 0 */
mas->last = 0;
+ mas->node = MAS_NONE;
return NULL;
}
@@ -6009,6 +6010,9 @@ void *mas_find(struct ma_state *mas, unsigned long max)
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;
--
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