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| author | Muchun Song <songmuchun@bytedance.com> | 2022-03-27 13:18:52 +0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2022-03-27 18:47:00 -0700 |
| commit | ae085d7f9365de7da27ab5c0d16b12d51ea7fca9 (patch) | |
| tree | 30c8132fb43e67b2cb216fe7ff2ff0cdccbf0e80 | |
| parent | f82da161ea75dc4db21b2499e4b1facd36dab275 (diff) | |
| download | linux-ae085d7f9365de7da27ab5c0d16b12d51ea7fca9.tar.gz linux-ae085d7f9365de7da27ab5c0d16b12d51ea7fca9.tar.bz2 linux-ae085d7f9365de7da27ab5c0d16b12d51ea7fca9.zip | |
mm: kfence: fix missing objcg housekeeping for SLAB
The objcg is not cleared and put for kfence object when it is freed,
which could lead to memory leak for struct obj_cgroup and wrong
statistics of NR_SLAB_RECLAIMABLE_B or NR_SLAB_UNRECLAIMABLE_B.
Since the last freed object's objcg is not cleared,
mem_cgroup_from_obj() could return the wrong memcg when this kfence
object, which is not charged to any objcgs, is reallocated to other
users.
A real word issue [1] is caused by this bug.
Link: https://lore.kernel.org/all/000000000000cabcb505dae9e577@google.com/ [1]
Reported-by: syzbot+f8c45ccc7d5d45fc5965@syzkaller.appspotmail.com
Fixes: d3fb45f370d9 ("mm, kfence: insert KFENCE hooks for SLAB")
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | mm/slab.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/mm/slab.c b/mm/slab.c index d9dec7a8fd79..b04e40078bdf 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -3422,6 +3422,7 @@ static __always_inline void __cache_free(struct kmem_cache *cachep, void *objp, if (is_kfence_address(objp)) { kmemleak_free_recursive(objp, cachep->flags); + memcg_slab_free_hook(cachep, &objp, 1); __kfence_free(objp); return; } |