This is a note to let you know that I've just added the patch titled
maple_tree: fix a potential memory leak, OOB access, or other unpredictable bug
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-a-potential-memory-leak-oob-access-or-other-unpredictable-bug.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 1f5f12ece722aacea1769fb644f27790ede339dc Mon Sep 17 00:00:00 2001
From: Peng Zhang <zhangpeng.00@xxxxxxxxxxxxx>
Date: Tue, 11 Apr 2023 12:10:04 +0800
Subject: maple_tree: fix a potential memory leak, OOB access, or other unpredictable bug
From: Peng Zhang <zhangpeng.00@xxxxxxxxxxxxx>
commit 1f5f12ece722aacea1769fb644f27790ede339dc upstream.
In mas_alloc_nodes(), "node->node_count = 0" means to initialize the
node_count field of the new node, but the node may not be a new node. It
may be a node that existed before and node_count has a value, setting it
to 0 will cause a memory leak. At this time, mas->alloc->total will be
greater than the actual number of nodes in the linked list, which may
cause many other errors. For example, out-of-bounds access in
mas_pop_node(), and mas_pop_node() may return addresses that should not be
used. Fix it by initializing node_count only for new nodes.
Also, by the way, an if-else statement was removed to simplify the code.
Link: https://lkml.kernel.org/r/20230411041005.26205-1-zhangpeng.00@xxxxxxxxxxxxx
Fixes: 54a611b60590 ("Maple Tree: add new data structure")
Signed-off-by: Peng Zhang <zhangpeng.00@xxxxxxxxxxxxx>
Reviewed-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
lib/maple_tree.c | 19 +++++++------------
1 file changed, 7 insertions(+), 12 deletions(-)
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -1298,26 +1298,21 @@ static inline void mas_alloc_nodes(struc
node = mas->alloc;
node->request_count = 0;
while (requested) {
- max_req = MAPLE_ALLOC_SLOTS;
- if (node->node_count) {
- unsigned int offset = node->node_count;
-
- slots = (void **)&node->slot[offset];
- max_req -= offset;
- } else {
- slots = (void **)&node->slot;
- }
-
+ max_req = MAPLE_ALLOC_SLOTS - node->node_count;
+ slots = (void **)&node->slot[node->node_count];
max_req = min(requested, max_req);
count = mt_alloc_bulk(gfp, max_req, slots);
if (!count)
goto nomem_bulk;
+ if (node->node_count == 0) {
+ node->slot[0]->node_count = 0;
+ node->slot[0]->request_count = 0;
+ }
+
node->node_count += count;
allocated += count;
node = node->slot[0];
- node->node_count = 0;
- node->request_count = 0;
requested -= count;
}
mas->alloc->total = allocated;
Patches currently in stable-queue which might be from zhangpeng.00@xxxxxxxxxxxxx are
queue-6.2/maple_tree-fix-a-potential-memory-leak-oob-access-or-other-unpredictable-bug.patch
