====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ kworker/u8:1/13 is trying to acquire lock: ffff888034dc9450 (&disk->zone_revalidate_mutex){+.+.}-{4:4}, at: blk_revalidate_disk_zones+0x1c5/0x1650 block/blk-zoned.c:2560 but task is already holding lock: ffff88802dc8aef0 (&q->q_usage_counter(io)#74){++++}-{0:0}, at: blk_mq_freeze_queue include/linux/blk-mq.h:956 [inline] ffff88802dc8aef0 (&q->q_usage_counter(io)#74){++++}-{0:0}, at: nvme_update_ns_info+0x3ac/0x1200 drivers/nvme/host/core.c:2583 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&q->q_usage_counter(io)#74){++++}-{0:0}: blk_alloc_queue+0x544/0x690 block/blk-core.c:504 __blk_alloc_disk+0xe3/0x1d0 block/genhd.c:1527 nvme_mpath_alloc_disk+0x5c2/0x8b0 drivers/nvme/host/multipath.c:769 nvme_alloc_ns_head drivers/nvme/host/core.c:4049 [inline] nvme_init_ns_head drivers/nvme/host/core.c:4153 [inline] nvme_alloc_ns drivers/nvme/host/core.c:4267 [inline] nvme_scan_ns+0x2e22/0x46c0 drivers/nvme/host/core.c:4483 async_run_entry_fn+0x9d/0x430 kernel/async.c:129 process_one_work kernel/workqueue.c:3495 [inline] process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3578 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3659 kthread+0x38b/0x480 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 -> #2 (fs_reclaim){+.+.}-{0:0}: __fs_reclaim_acquire mm/page_alloc.c:4365 [inline] fs_reclaim_acquire+0x71/0x100 mm/page_alloc.c:4379 might_alloc include/linux/sched/mm.h:316 [inline] slab_pre_alloc_hook mm/slub.c:4673 [inline] slab_alloc_node mm/slub.c:5011 [inline] __kmalloc_cache_node_noprof+0x66/0x620 mm/slub.c:5695 _kmalloc_node_noprof include/linux/slab.h:1196 [inline] alloc_worker kernel/workqueue.c:2853 [inline] init_rescuer+0x167/0x530 kernel/workqueue.c:6002 workqueue_init+0x214/0x680 kernel/workqueue.c:8517 kernel_init_freeable+0x26b/0x3e0 init/main.c:1658 kernel_init+0x22/0x1d0 init/main.c:1563 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 -> #1 (wq_pool_mutex){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x197/0x15a0 kernel/locking/mutex.c:821 __alloc_workqueue+0xe8d/0x21d0 kernel/workqueue.c:6201 alloc_workqueue_va kernel/workqueue.c:6253 [inline] alloc_workqueue_noprof+0xe3/0x210 kernel/workqueue.c:6269 disk_alloc_zone_resources block/blk-zoned.c:2101 [inline] blk_revalidate_disk_zones+0x8d1/0x1650 block/blk-zoned.c:2575 null_add_dev+0x12b8/0x1d70 drivers/block/null_blk/main.c:2056 nullb_device_power_store+0x240/0x380 drivers/block/null_blk/main.c:511 flush_write_buffer fs/configfs/file.c:207 [inline] configfs_write_iter+0x337/0x430 fs/configfs/file.c:229 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x612/0xba0 fs/read_write.c:687 ksys_write+0x150/0x270 fs/read_write.c:739 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&disk->zone_revalidate_mutex){+.+.}-{4:4}: check_prev_add kernel/locking/lockdep.c:3209 [inline] check_prevs_add kernel/locking/lockdep.c:3328 [inline] validate_chain kernel/locking/lockdep.c:3952 [inline] __lock_acquire+0x164c/0x2de0 kernel/locking/lockdep.c:5288 lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5942 __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x197/0x15a0 kernel/locking/mutex.c:821 blk_revalidate_disk_zones+0x1c5/0x1650 block/blk-zoned.c:2560 nvme_mpath_revalidate_zones+0x106/0x1c0 drivers/nvme/host/multipath.c:301 nvme_update_ns_info+0x984/0x1200 drivers/nvme/host/core.c:2620 nvme_alloc_ns drivers/nvme/host/core.c:4293 [inline] nvme_scan_ns+0x34c1/0x46c0 drivers/nvme/host/core.c:4483 async_run_entry_fn+0x9d/0x430 kernel/async.c:129 process_one_work kernel/workqueue.c:3495 [inline] process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3578 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3659 kthread+0x38b/0x480 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 other info that might help us debug this: Chain exists of: &disk->zone_revalidate_mutex --> fs_reclaim --> &q->q_usage_counter(io)#74 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&q->q_usage_counter(io)#74); lock(fs_reclaim); lock(&q->q_usage_counter(io)#74); lock(&disk->zone_revalidate_mutex); *** DEADLOCK *** locks held by kworker/u8:1/13: 4, last CPU#0: #0: ffff88801c29b948 ((wq_completion)async){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffff88801c29b948 ((wq_completion)async){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffff88801c29b948 ((wq_completion)async){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline] #0: ffff88801c29b948 ((wq_completion)async){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578 #1: ffffc90000127c40 ((work_completion)(&entry->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffc90000127c40 ((work_completion)(&entry->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffc90000127c40 ((work_completion)(&entry->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline] #1: ffffc90000127c40 ((work_completion)(&entry->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578 #2: ffff88802dc8aef0 (&q->q_usage_counter(io)#74){++++}-{0:0}, at: blk_mq_freeze_queue include/linux/blk-mq.h:956 [inline] #2: ffff88802dc8aef0 (&q->q_usage_counter(io)#74){++++}-{0:0}, at: nvme_update_ns_info+0x3ac/0x1200 drivers/nvme/host/core.c:2583 #3: ffff88802dc8af28 (&q->q_usage_counter(queue)#58){+.+.}-{0:0}, at: blk_mq_freeze_queue include/linux/blk-mq.h:956 [inline] #3: ffff88802dc8af28 (&q->q_usage_counter(queue)#58){+.+.}-{0:0}, at: nvme_update_ns_info+0x3ac/0x1200 drivers/nvme/host/core.c:2583 stack backtrace: CPU: 0 UID: 0 PID: 13 Comm: kworker/u8:1 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Workqueue: async async_run_entry_fn Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_circular_bug+0x2e2/0x300 kernel/locking/lockdep.c:2087 check_noncircular+0x12f/0x150 kernel/locking/lockdep.c:2219 check_prev_add kernel/locking/lockdep.c:3209 [inline] check_prevs_add kernel/locking/lockdep.c:3328 [inline] validate_chain kernel/locking/lockdep.c:3952 [inline] __lock_acquire+0x164c/0x2de0 kernel/locking/lockdep.c:5288 lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5942 __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x197/0x15a0 kernel/locking/mutex.c:821 blk_revalidate_disk_zones+0x1c5/0x1650 block/blk-zoned.c:2560 nvme_mpath_revalidate_zones+0x106/0x1c0 drivers/nvme/host/multipath.c:301 nvme_update_ns_info+0x984/0x1200 drivers/nvme/host/core.c:2620 nvme_alloc_ns drivers/nvme/host/core.c:4293 [inline] nvme_scan_ns+0x34c1/0x46c0 drivers/nvme/host/core.c:4483 async_run_entry_fn+0x9d/0x430 kernel/async.c:129 process_one_work kernel/workqueue.c:3495 [inline] process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3578 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3659 kthread+0x38b/0x480 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245