Commit f6982769 authored May 22, 2026 by Damien Le Moal Committed by Jens Axboe May 22, 2026

block: avoid use-after-free in disk_free_zone_resources()



The function disk_update_zone_resources() may call
disk_free_zone_resources() in case of error, and following this,
blk_revalidate_disk_zones() will again calls disk_free_zone_resources() if
disk_update_zone_resources() failed. If a zone worker thread is being used
(which is the default for a rotational media zoned device),
disk_free_zone_resources() will try to stop the zone worker thread twice
because disk->zone_wplugs_worker is not reset to NULL when the worker
thread is stopped the first time.

In disk_free_zone_resources(), fix this by correctly clearing
disk->zone_wplugs_worker to NULL when the worker thread is stopped.

And while at it, since disk_free_zone_resources() is always called after a
failed call to disk_update_zone_resources(), remove the unnecessary call
to disk_free_zone_resources() in disk_update_zone_resources().

Fixes: 1365b690 ("block: allow submitting all zone writes from a single context")
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://patch.msgid.link/20260522115622.588535-1-dlemoal@kernel.org


Signed-off-by: Jens Axboe <axboe@kernel.dk>

parent dc278e9b

block/blk-zoned.c

+3 −4

Original line number	Diff line number	Diff line
		@@ -2001,8 +2001,10 @@ static void disk_set_zones_cond_array(struct gendisk disk, u8 zones_cond)

		void disk_free_zone_resources(struct gendisk *disk)
		{
		if (disk->zone_wplugs_worker)
		if (disk->zone_wplugs_worker) {
		kthread_stop(disk->zone_wplugs_worker);
		disk->zone_wplugs_worker = NULL;
		}
		WARN_ON_ONCE(!list_empty(&disk->zone_wplugs_list));

		if (disk->zone_wplugs_wq) {
		@@ -2135,9 +2137,6 @@ static int disk_update_zone_resources(struct gendisk *disk,
		ret = queue_limits_commit_update(q, &lim);

		unfreeze:
		if (ret)
		disk_free_zone_resources(disk);

		blk_mq_unfreeze_queue(q, memflags);

		return ret;