[v3,02/48] maple_tree: Fix potential rcu issue

Commit Message

Liam R. Howlett Jan. 17, 2023, 2:34 a.m. UTC

From: "Liam R. Howlett" <[e-mail]>

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

Signed-off-by: Liam R. Howlett <[e-mail]>
---
 lib/maple_tree.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Patch

diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index b990ccea454e..c15e63ac6e93 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -4661,13 +4661,13 @@  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;