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From:   "Liam R. Howlett" <Liam.Howlett@oracle.com>
To:     linux-mm@kvack.org, linux-kernel@vger.kernel.org,
        Andrew Morton <akpm@linux-foundation.org>,
        maple-tree@lists.infradead.org
Cc:     "Liam R. Howlett" <Liam.Howlett@Oracle.com>,
        "Liam R . Howlett" <Liam.Howlett@oracle.com>
Subject: [PATCH v4 02/49] maple_tree: Fix potential rcu issue
Date:   Fri, 20 Jan 2023 11:26:03 -0500
Message-Id: <20230120162650.984577-3-Liam.Howlett@oracle.com>
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From: "Liam R. Howlett" <Liam.Howlett@Oracle.com>

Ensure the node isn't dead after reading the node end.

Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
---
 lib/maple_tree.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index cb8c03c4dce7..cbb8bd9b9d25 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -4654,13 +4654,13 @@ static inline void *mas_next_nentry(struct ma_state *mas,
 	pivots = ma_pivots(node, type);
 	slots = ma_slots(node, type);
 	mas->index = mas_safe_min(mas, pivots, mas->offset);
+	count = ma_data_end(node, type, pivots, mas->max);
 	if (ma_dead_node(node))
 		return NULL;
 
 	if (mas->index > max)
 		return NULL;
 
-	count = ma_data_end(node, type, pivots, mas->max);
 	if (mas->offset > count)
 		return NULL;
 
-- 
2.35.1