From: "Liam R. Howlett" <Liam.Howlett@xxxxxxxxxx> 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@xxxxxxxxxx Cc: <Stable@xxxxxxxxxxxxxxx> Fixes: 54a611b60590 ("Maple Tree: add new data structure") Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- lib/maple_tree.c | 10 ++++++++++ 1 file changed, 10 insertions(+) --- a/lib/maple_tree.c +++ b/lib/maple_tree.c @@ -4731,6 +4731,11 @@ static inline void *mas_next_entry(struc 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(struc { 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);
