The patch titled
Subject: mm-list_lru-fix-uaf-for-memory-cgroup-v2
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
mm-list_lru-fix-uaf-for-memory-cgroup-v2.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-list_lru-fix-uaf-for-memory-cgroup-v2.patch
This patch will later appear in the mm-hotfixes-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Muchun Song <songmuchun@xxxxxxxxxxxxx>
Subject: mm-list_lru-fix-uaf-for-memory-cgroup-v2
Date: Thu, 1 Aug 2024 10:46:03 +0800
only grab rcu lock when necessary, per Vlastimil
Link: https://lkml.kernel.org/r/20240801024603.1865-1-songmuchun@xxxxxxxxxxxxx
Fixes: 0a97c01cd20b ("list_lru: allow explicit memcg and NUMA node selection")
Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx>
Acked-by: Shakeel Butt <shakeel.butt@xxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Nhat Pham <nphamcs@xxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/list_lru.c | 24 ++++++++++++++----------
1 file changed, 14 insertions(+), 10 deletions(-)
--- a/mm/list_lru.c~mm-list_lru-fix-uaf-for-memory-cgroup-v2
+++ a/mm/list_lru.c
@@ -112,12 +112,14 @@ bool list_lru_add_obj(struct list_lru *l
{
bool ret;
int nid = page_to_nid(virt_to_page(item));
- struct mem_cgroup *memcg;
- rcu_read_lock();
- memcg = list_lru_memcg_aware(lru) ? mem_cgroup_from_slab_obj(item) : NULL;
- ret = list_lru_add(lru, item, nid, memcg);
- rcu_read_unlock();
+ if (list_lru_memcg_aware(lru)) {
+ rcu_read_lock();
+ ret = list_lru_add(lru, item, nid, mem_cgroup_from_slab_obj(item));
+ rcu_read_unlock();
+ } else {
+ ret = list_lru_add(lru, item, nid, NULL);
+ }
return ret;
}
@@ -148,12 +150,14 @@ bool list_lru_del_obj(struct list_lru *l
{
bool ret;
int nid = page_to_nid(virt_to_page(item));
- struct mem_cgroup *memcg;
- rcu_read_lock();
- memcg = list_lru_memcg_aware(lru) ? mem_cgroup_from_slab_obj(item) : NULL;
- ret = list_lru_del(lru, item, nid, memcg);
- rcu_read_unlock();
+ if (list_lru_memcg_aware(lru)) {
+ rcu_read_lock();
+ ret = list_lru_del(lru, item, nid, mem_cgroup_from_slab_obj(item));
+ rcu_read_unlock();
+ } else {
+ ret = list_lru_del(lru, item, nid, NULL);
+ }
return ret;
}
_
Patches currently in -mm which might be from songmuchun@xxxxxxxxxxxxx are
mm-list_lru-fix-uaf-for-memory-cgroup.patch
mm-list_lru-fix-uaf-for-memory-cgroup-v2.patch
mm-kmem-remove-mem_cgroup_from_obj.patch
