On Tue, May 9, 2023 at 3:23 PM Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> wrote:
syzbot is reporting sleep in RCU context, for commit d66c718d28ac
("workingset: refactor LRU refault to expose refault recency check")
missed rcu_read_unlock().

Reported-by: syzbot <syzbot+3c6cac1550288f8e7060@syzkaller.appspotmail.com>
Closes: https://syzkaller.appspot.com/bug?extid=3c6cac1550288f8e7060
Signed-off-by
: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Fixes: d66c718d28ac ("workingset: refactor LRU refault to expose refault recency check")
---
 mm/workingset.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/workingset.c b/mm/workingset.c
index d81f9dafc9f1..90ae785d4c9c 100644
--- a/mm/workingset.c
+++ b/mm/workingset.c
@@ -303,7 +303,7 @@ static void lru_gen_refault(struct folio *folio, void *shadow)
                goto unlock;

        if (pgdat != folio_pgdat(folio))
-               return;
+               goto unlock;

        lruvec = mem_cgroup_lruvec(memcg, pgdat);
        lrugen = &lruvec->lrugen;
--
2.18.4

Thanks for the fix!
Acked-by: Nhat Pham <nphamcs@gmail.com>