Make mas->min and mas->max point to a node range instead of a leaf entry range. This allows mas to still be usable after mas_empty_area() returns. Users would get unexpected results from other operations on the maple state after calling the affected function.
Reported-by: "Edgecombe, Rick P" rick.p.edgecombe@intel.com Reported-by: Tad support@spotco.us Reported-by: Michael Keyes mgkeyes@vigovproductions.net Link: https://lore.kernel.org/linux-mm/32f156ba80010fd97dbaf0a0cdfc84366608624d.ca... Link: https://lore.kernel.org/linux-mm/e6108286ac025c268964a7ead3aab9899f9bc6e9.ca... Fixes: 54a611b60590 ("Maple Tree: add new data structure") Cc: Stable@vger.kernel.org Signed-off-by: Peng Zhang zhangpeng.00@bytedance.com --- lib/maple_tree.c | 12 +++--------- 1 file changed, 3 insertions(+), 9 deletions(-)
diff --git a/lib/maple_tree.c b/lib/maple_tree.c index 110a36479dced..8ebc43d4cc8c5 100644 --- a/lib/maple_tree.c +++ b/lib/maple_tree.c @@ -5317,15 +5317,9 @@ int mas_empty_area(struct ma_state *mas, unsigned long min,
mt = mte_node_type(mas->node); pivots = ma_pivots(mas_mn(mas), mt); - if (offset) - mas->min = pivots[offset - 1] + 1; - - if (offset < mt_pivots[mt]) - mas->max = pivots[offset]; - - if (mas->index < mas->min) - mas->index = mas->min; - + min = mas_safe_min(mas, pivots, offset); + if (mas->index < min) + mas->index = min; mas->last = mas->index + size - 1; return 0; }