2023-04-11 15:13:26

by Liam R. Howlett

[permalink] [raw]
Subject: [PATCH 6.1 02/14] maple_tree: fix potential rcu issue

From: "Liam R. Howlett" <[email protected]>

commit 65be6f058b0eba98dc6c6f197ea9f62c9b6a519f upstream.

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

Link: https://lkml.kernel.org/r/[email protected]
Cc: <[email protected]>
Fixes: 54a611b60590 ("Maple Tree: add new data structure")
Signed-off-by: Liam R. Howlett <[email protected]>
---
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 fd824b065ace..1ade7748cc9b 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -4656,13 +4656,13 @@ 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;

--
2.39.2