From f6982769910ecddabdb5b8b9afdab0bb8b6668ac Mon Sep 17 00:00:00 2001 From: Damien Le Moal Date: Fri, 22 May 2026 20:56:22 +0900 Subject: [PATCH] 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: 1365b6904fd0 ("block: allow submitting all zone writes from a single context") Signed-off-by: Damien Le Moal Reviewed-by: Christoph Hellwig Link: https://patch.msgid.link/20260522115622.588535-1-dlemoal@kernel.org Signed-off-by: Jens Axboe --- block/blk-zoned.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/block/blk-zoned.c b/block/blk-zoned.c index 42ef830054dc..6a221c180889 100644 --- a/block/blk-zoned.c +++ b/block/blk-zoned.c @@ -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;