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| author | Muchun Song <songmuchun@bytedance.com> | 2024-07-18 16:36:07 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-08-14 15:34:34 +0200 |
| commit | 4589f77c18dd98b65f45617b6d1e95313cf6fcab (patch) | |
| tree | b432c2882cf6858345506fa1af8a8e5010d3416e /mm | |
| parent | a6ce683090e5193a57dc59f354153c0e57a25470 (diff) | |
| download | linux-4589f77c18dd98b65f45617b6d1e95313cf6fcab.tar.gz linux-4589f77c18dd98b65f45617b6d1e95313cf6fcab.tar.bz2 linux-4589f77c18dd98b65f45617b6d1e95313cf6fcab.zip | |
mm: list_lru: fix UAF for memory cgroup
commit 5161b48712dcd08ec427c450399d4d1483e21dea upstream.
The mem_cgroup_from_slab_obj() is supposed to be called under rcu lock or
cgroup_mutex or others which could prevent returned memcg from being
freed. Fix it by adding missing rcu read lock.
Found by code inspection.
[songmuchun@bytedance.com: only grab rcu lock when necessary, per Vlastimil]
Link: https://lkml.kernel.org/r/20240801024603.1865-1-songmuchun@bytedance.com
Link: https://lkml.kernel.org/r/20240718083607.42068-1-songmuchun@bytedance.com
Fixes: 0a97c01cd20b ("list_lru: allow explicit memcg and NUMA node selection")
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/list_lru.c | 28 |
1 files changed, 22 insertions, 6 deletions
diff --git a/mm/list_lru.c b/mm/list_lru.c index 3fd64736bc45..6ac393ea7439 100644 --- a/mm/list_lru.c +++ b/mm/list_lru.c @@ -85,6 +85,7 @@ list_lru_from_memcg_idx(struct list_lru *lru, int nid, int idx) } #endif /* CONFIG_MEMCG_KMEM */ +/* The caller must ensure the memcg lifetime. */ bool list_lru_add(struct list_lru *lru, struct list_head *item, int nid, struct mem_cgroup *memcg) { @@ -109,14 +110,22 @@ EXPORT_SYMBOL_GPL(list_lru_add); bool list_lru_add_obj(struct list_lru *lru, struct list_head *item) { + bool ret; int nid = page_to_nid(virt_to_page(item)); - struct mem_cgroup *memcg = list_lru_memcg_aware(lru) ? - mem_cgroup_from_slab_obj(item) : NULL; - return list_lru_add(lru, item, nid, memcg); + 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; } EXPORT_SYMBOL_GPL(list_lru_add_obj); +/* The caller must ensure the memcg lifetime. */ bool list_lru_del(struct list_lru *lru, struct list_head *item, int nid, struct mem_cgroup *memcg) { @@ -139,11 +148,18 @@ EXPORT_SYMBOL_GPL(list_lru_del); bool list_lru_del_obj(struct list_lru *lru, struct list_head *item) { + bool ret; int nid = page_to_nid(virt_to_page(item)); - struct mem_cgroup *memcg = list_lru_memcg_aware(lru) ? - mem_cgroup_from_slab_obj(item) : NULL; - return list_lru_del(lru, item, nid, memcg); + 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; } EXPORT_SYMBOL_GPL(list_lru_del_obj); |