From: Ming Lei <ming.lei@xxxxxxxxxx> commit daaca3522a8e67c46e39ef09c1d542e866f85f3b upstream. blkcg_init_queue() may add rq qos structures to request queue, previously blk_cleanup_queue() calls rq_qos_exit() to release them, but commit 8e141f9eb803 ("block: drain file system I/O on del_gendisk") moves rq_qos_exit() into del_gendisk(), so memory leak is caused because queues may not have disk, such as un-present scsi luns, nvme admin queue, ... Fixes the issue by adding rq_qos_exit() to blk_cleanup_queue() back. BTW, v5.18 won't need this patch any more since we move blkcg_init_queue()/blkcg_exit_queue() into disk allocation/release handler, and patches have been in for-5.18/block. Cc: Christoph Hellwig <hch@xxxxxx> Cc: stable@xxxxxxxxxxxxxxx Fixes: 8e141f9eb803 ("block: drain file system I/O on del_gendisk") Reported-by: syzbot+b42749a851a47a0f581b@xxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx> Reviewed-by: Bart Van Assche <bvanassche@xxxxxxx> Reviewed-by: Christoph Hellwig <hch@xxxxxx> Link: https://lore.kernel.org/r/20220314043018.177141-1-ming.lei@xxxxxxxxxx Signed-off-by: Jens Axboe <axboe@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- block/blk-core.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/block/blk-core.c +++ b/block/blk-core.c @@ -49,6 +49,7 @@ #include "blk-mq.h" #include "blk-mq-sched.h" #include "blk-pm.h" +#include "blk-rq-qos.h" struct dentry *blk_debugfs_root; @@ -380,6 +381,9 @@ void blk_cleanup_queue(struct request_qu */ blk_freeze_queue(q); + /* cleanup rq qos structures for queue without disk */ + rq_qos_exit(q); + blk_queue_flag_set(QUEUE_FLAG_DEAD, q); blk_sync_queue(q);