diff options
| author | Ming Lei <ming.lei@redhat.com> | 2022-12-15 05:16:29 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-10-10 23:00:37 +0300 |
| commit | 752ec2d93e75ee5a473086f6f6859ea5ba9fb114 (patch) | |
| tree | 72c644d40677cb624fbbfd8ec69cf2b804d243b9 /block | |
| parent | 77d0e7e8e58273c09efb6095661af010843c0048 (diff) | |
| download | linux-752ec2d93e75ee5a473086f6f6859ea5ba9fb114.tar.xz | |
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-sysfs.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index a582ea0da74f..a82bdec923b2 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -737,6 +737,7 @@ 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_get_queue_kmem_cache(blk_queue_has_srcu(q)), q); } @@ -762,8 +763,6 @@ static void blk_release_queue(struct kobject *kobj) might_sleep(); - percpu_ref_exit(&q->q_usage_counter); - if (q->poll_stat) blk_stat_remove_callback(q, q->poll_cb); blk_stat_free_callback(q->poll_cb); |