From 1535c813e5a95d31db776898cc354f51c5065b3f Mon Sep 17 00:00:00 2001 From: "Liam R. Howlett" Date: Thu, 17 Nov 2022 14:32:36 -0500 Subject: [PATCH] maple_tree: Reduce user error potential When iterating, a user may operate on the tree and cause the maple state to be altered and left in an unintuitive state. Detect this scenario and correct it by setting to the limit and invalidating the state. Signed-off-by: Liam R. Howlett --- lib/maple_tree.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/lib/maple_tree.c b/lib/maple_tree.c index ff28bd6d4745..440539ff0d11 100644 --- a/lib/maple_tree.c +++ b/lib/maple_tree.c @@ -4735,6 +4735,11 @@ static inline void *mas_next_entry(struct ma_state *mas, unsigned long limit) unsigned long last; enum maple_type mt; + if (mas->index > limit) { + mas->index = mas->last = limit; + mas_pause(mas); + return NULL; + } last = mas->last; retry: offset = mas->offset; @@ -4841,6 +4846,11 @@ static inline void *mas_prev_entry(struct ma_state *mas, unsigned long min) { void *entry; + if (mas->index < min) { + mas->index = mas->last = min; + mas_pause(mas); + return NULL; + } retry: while (likely(!mas_is_none(mas))) { entry = mas_prev_nentry(mas, min, mas->index); -- 2.50.1