diff options
| author | Yu Zhao <yuzhao@google.com> | 2023-01-16 04:44:05 +0100 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2023-02-01 01:44:08 +0100 |
| commit | de08eaa6156405f2e9369f06ba5afae0e4ab3b62 (patch) | |
| tree | afecbef6ee74d6008b818560c1ded48f6002fcbd /mm/vmscan.c | |
| parent | Revert "mm: add nodes= arg to memory.reclaim" (diff) | |
| download | linux-de08eaa6156405f2e9369f06ba5afae0e4ab3b62.tar.xz linux-de08eaa6156405f2e9369f06ba5afae0e4ab3b62.zip | |
mm: multi-gen LRU: fix crash during cgroup migration
lru_gen_migrate_mm() assumes lru_gen_add_mm() runs prior to itself. This
isn't true for the following scenario:
CPU 1 CPU 2
clone()
cgroup_can_fork()
cgroup_procs_write()
cgroup_post_fork()
task_lock()
lru_gen_migrate_mm()
task_unlock()
task_lock()
lru_gen_add_mm()
task_unlock()
And when the above happens, kernel crashes because of linked list
corruption (mm_struct->lru_gen.list).
Link: https://lore.kernel.org/r/20230115134651.30028-1-msizanoen@qtmlabs.xyz/
Link: https://lkml.kernel.org/r/20230116034405.2960276-1-yuzhao@google.com
Fixes: bd74fdaea146 ("mm: multi-gen LRU: support page table walks")
Signed-off-by: Yu Zhao <yuzhao@google.com>
Reported-by: msizanoen <msizanoen@qtmlabs.xyz>
Tested-by: msizanoen <msizanoen@qtmlabs.xyz>
Cc: <stable@vger.kernel.org> [6.1+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/vmscan.c')
| -rw-r--r-- | mm/vmscan.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/mm/vmscan.c b/mm/vmscan.c index e83d2a74e942..bf3eedf0209c 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -3323,13 +3323,16 @@ void lru_gen_migrate_mm(struct mm_struct *mm) if (mem_cgroup_disabled()) return; + /* migration can happen before addition */ + if (!mm->lru_gen.memcg) + return; + rcu_read_lock(); memcg = mem_cgroup_from_task(task); rcu_read_unlock(); if (memcg == mm->lru_gen.memcg) return; - VM_WARN_ON_ONCE(!mm->lru_gen.memcg); VM_WARN_ON_ONCE(list_empty(&mm->lru_gen.list)); lru_gen_del_mm(mm); |