diff options
| author | Ming Lei <ming.lei@redhat.com> | 2022-12-15 10:16:29 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-10-10 21:59:05 +0200 |
| commit | 3f59e63568adb57bc0703942b6d2c99e4f1595b1 (patch) | |
| tree | 8197432d6598ce2e98374d5385b46f2fa8c66133 /block | |
| parent | b75b017b3f375604e18b829e7de78e440c9ebe5a (diff) | |
block: fix use-after-free of q->q_usage_counter
commit d36a9ea5e7766961e753ee38d4c331bbe6ef659b upstream.
For blk-mq, queue release handler is usually called after
blk_mq_freeze_queue_wait() returns. However, the
q_usage_counter->release() handler may not be run yet at that time, so
this can cause a use-after-free.
Fix the issue by moving percpu_ref_exit() into blk_free_queue_rcu().
Since ->release() is called with rcu read lock held, it is agreed that
the race should be covered in caller per discussion from the two links.
Reported-by: Zhang Wensheng <zhangwensheng@huaweicloud.com>
Reported-by: Zhong Jinghua <zhongjinghua@huawei.com>
Link: https://lore.kernel.org/linux-block/Y5prfOjyyjQKUrtH@T590/T/#u
Link: https://lore.kernel.org/lkml/Y4%2FmzMd4evRg9yDi@fedora/
Cc: Hillf Danton <hdanton@sina.com>
Cc: Yu Kuai <yukuai3@huawei.com>
Cc: Dennis Zhou <dennis@kernel.org>
Fixes: 2b0d3d3e4fcf ("percpu_ref: reduce memory footprint of percpu_ref in fast path")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20221215021629.74870-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Saranya Muruganandam <saranyamohan@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'block')
| -rw-r--r-- | block/blk-core.c | 2 | ||||
| -rw-r--r-- | block/blk-sysfs.c | 2 |
2 files changed, 2 insertions, 2 deletions
diff --git a/block/blk-core.c b/block/blk-core.c index 0c4a4e42ad87..fbbd59e6d7e1 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -405,8 +405,6 @@ void blk_cleanup_queue(struct request_queue *q) blk_mq_sched_free_requests(q); mutex_unlock(&q->sysfs_lock); - percpu_ref_exit(&q->q_usage_counter); - /* @q is and will stay empty, shutdown and put */ blk_put_queue(q); } diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index 00021f012370..4ea84e46a665 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -748,6 +748,8 @@ static void blk_free_queue_rcu(struct rcu_head *rcu_head) { struct request_queue *q = container_of(rcu_head, struct request_queue, rcu_head); + + percpu_ref_exit(&q->q_usage_counter); kmem_cache_free(blk_requestq_cachep, q); } |