From 2c9bc4903b96da06220c81b056d6506b2e8e50ad Mon Sep 17 00:00:00 2001 From: "Liam R. Howlett" Date: Tue, 11 Apr 2023 11:10:44 -0400 Subject: [PATCH] maple_tree: reduce user error potential commit 50e81c82ad947045c7ed26ddc9acb17276b653b6 upstream. 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. Link: https://lkml.kernel.org/r/20230120162650.984577-4-Liam.Howlett@oracle.com Cc: Fixes: 54a611b60590 ("Maple Tree: add new data structure") Signed-off-by: Liam R. Howlett Signed-off-by: Greg Kroah-Hartman --- lib/maple_tree.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/lib/maple_tree.c b/lib/maple_tree.c index f8e1e85dd7a6..360b4bbccd33 100644 --- a/lib/maple_tree.c +++ b/lib/maple_tree.c @@ -4731,6 +4731,11 @@ 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; @@ -4837,6 +4842,11 @@ 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