This is a note to let you know that I've just added the patch titled
maple_tree: fix mas_empty_area() search
to the 6.2-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
maple_tree-fix-mas_empty_area-search.patch
and it can be found in the queue-6.2 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 06e8fd999334bcd76b4d72d7b9206d4aea89764e Mon Sep 17 00:00:00 2001
From: "Liam R. Howlett" <Liam.Howlett@xxxxxxxxxx>
Date: Fri, 14 Apr 2023 10:57:27 -0400
Subject: maple_tree: fix mas_empty_area() search
From: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
commit 06e8fd999334bcd76b4d72d7b9206d4aea89764e upstream.
The internal function of mas_awalk() was incorrectly skipping the last
entry in a node, which could potentially be NULL. This is only a problem
for the left-most node in the tree - otherwise that NULL would not exist.
Fix mas_awalk() by using the metadata to obtain the end of the node for
the loop and the logical pivot as apposed to the raw pivot value.
Link: https://lkml.kernel.org/r/20230414145728.4067069-2-Liam.Howlett@xxxxxxxxxx
Fixes: 54a611b60590 ("Maple Tree: add new data structure")
Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
Reported-by: Rick Edgecombe <rick.p.edgecombe@xxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
lib/maple_tree.c | 20 +++++++++++---------
1 file changed, 11 insertions(+), 9 deletions(-)
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -5064,10 +5064,10 @@ static inline bool mas_anode_descend(str
{
enum maple_type type = mte_node_type(mas->node);
unsigned long pivot, min, gap = 0;
- unsigned char offset;
- unsigned long *gaps;
- unsigned long *pivots = ma_pivots(mas_mn(mas), type);
- void __rcu **slots = ma_slots(mas_mn(mas), type);
+ unsigned char offset, data_end;
+ unsigned long *gaps, *pivots;
+ void __rcu **slots;
+ struct maple_node *node;
bool found = false;
if (ma_is_dense(type)) {
@@ -5075,13 +5075,15 @@ static inline bool mas_anode_descend(str
return true;
}
- gaps = ma_gaps(mte_to_node(mas->node), type);
+ node = mas_mn(mas);
+ pivots = ma_pivots(node, type);
+ slots = ma_slots(node, type);
+ gaps = ma_gaps(node, type);
offset = mas->offset;
min = mas_safe_min(mas, pivots, offset);
- for (; offset < mt_slots[type]; offset++) {
- pivot = mas_safe_pivot(mas, pivots, offset, type);
- if (offset && !pivot)
- break;
+ data_end = ma_data_end(node, type, pivots, mas->max);
+ for (; offset <= data_end; offset++) {
+ pivot = mas_logical_pivot(mas, pivots, offset, type);
/* Not within lower bounds */
if (mas->index > pivot)
Patches currently in stable-queue which might be from Liam.Howlett@xxxxxxxxxx are
queue-6.2/maple_tree-make-maple-state-reusable-after-mas_empty_area_rev.patch
queue-6.2/maple_tree-fix-a-potential-memory-leak-oob-access-or-other-unpredictable-bug.patch
queue-6.2/maple_tree-fix-mas_empty_area-search.patch
