Commit 24ecc358 authored by Bart Van Assche's avatar Bart Van Assche Committed by Jens Axboe

block: Ensure that a request queue is dissociated from the cgroup controller

Several block drivers call alloc_disk() followed by put_disk() if
something fails before device_add_disk() is called without calling
blk_cleanup_queue(). Make sure that also for this scenario a request
queue is dissociated from the cgroup controller. This patch avoids
that loading the parport_pc, paride and pf drivers triggers the
following kernel crash:

BUG: KASAN: null-ptr-deref in pi_init+0x42e/0x580 [paride]
Read of size 4 at addr 0000000000000008 by task modprobe/744
Call Trace:
dump_stack+0x9a/0xeb
kasan_report+0x139/0x350
pi_init+0x42e/0x580 [paride]
pf_init+0x2bb/0x1000 [pf]
do_one_initcall+0x8e/0x405
do_init_module+0xd9/0x2f2
load_module+0x3ab4/0x4700
SYSC_finit_module+0x176/0x1a0
do_syscall_64+0xee/0x2b0
entry_SYSCALL_64_after_hwframe+0x42/0xb7
Reported-by: default avatarAlexandru Moise <00moses.alexander00@gmail.com>
Fixes: a063057d ("block: Fix a race between request queue removal and the block cgroup controller") # v4.17
Signed-off-by: default avatarBart Van Assche <bart.vanassche@wdc.com>
Tested-by: default avatarAlexandru Moise <00moses.alexander00@gmail.com>
Reviewed-by: default avatarJohannes Thumshirn <jthumshirn@suse.de>
Cc: Tejun Heo <tj@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Alexandru Moise <00moses.alexander00@gmail.com>
Cc: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 4cf6324b
...@@ -802,6 +802,21 @@ static void __blk_release_queue(struct work_struct *work) ...@@ -802,6 +802,21 @@ static void __blk_release_queue(struct work_struct *work)
blk_stat_remove_callback(q, q->poll_cb); blk_stat_remove_callback(q, q->poll_cb);
blk_stat_free_callback(q->poll_cb); blk_stat_free_callback(q->poll_cb);
if (!blk_queue_dead(q)) {
/*
* Last reference was dropped without having called
* blk_cleanup_queue().
*/
WARN_ONCE(blk_queue_init_done(q),
"request queue %p has been registered but blk_cleanup_queue() has not been called for that queue\n",
q);
blk_exit_queue(q);
}
WARN(blkg_root_lookup(q),
"request queue %p is being released but it has not yet been removed from the blkcg controller\n",
q);
blk_free_queue_stats(q->stats); blk_free_queue_stats(q->stats);
blk_exit_rl(q, &q->root_rl); blk_exit_rl(q, &q->root_rl);
......
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