sd 1:0:0:0: [sdb] Test Unit Ready failed: Result: hostbyte=DID_NO_CONNECT driverbyte=DRIVER_OK sd 1:0:0:0: [sdb] Read Capacity(10) failed: Result: hostbyte=DID_NO_CONNECT driverbyte=DRIVER_OK sd 1:0:0:0: [sdb] Sense not available. ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Tainted: G L ------------------------------------------------------ kworker/u8:3/49 is trying to acquire lock: ffffffff8f090420 (fs_reclaim){+.+.}-{0:0}, at: might_alloc include/linux/sched/mm.h:316 [inline] ffffffff8f090420 (fs_reclaim){+.+.}-{0:0}, at: slab_pre_alloc_hook mm/slub.c:4636 [inline] ffffffff8f090420 (fs_reclaim){+.+.}-{0:0}, at: slab_alloc_node mm/slub.c:4974 [inline] ffffffff8f090420 (fs_reclaim){+.+.}-{0:0}, at: __do_kmalloc_node mm/slub.c:5418 [inline] ffffffff8f090420 (fs_reclaim){+.+.}-{0:0}, at: __kmalloc_noprof+0xbc/0x710 mm/slub.c:5444 but task is already holding lock: ffff888012ece3b8 (&q->limits_lock){+.+.}-{4:4}, at: queue_limits_start_update include/linux/blkdev.h:1101 [inline] ffff888012ece3b8 (&q->limits_lock){+.+.}-{4:4}, at: sd_revalidate_disk+0xb88/0xb350 drivers/scsi/sd.c:3803 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&q->limits_lock){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x197/0x15a0 kernel/locking/mutex.c:821 queue_limits_start_update include/linux/blkdev.h:1101 [inline] disk_update_zone_resources block/blk-zoned.c:2067 [inline] blk_revalidate_disk_zones+0xad9/0x12e0 block/blk-zoned.c:2375 nvme_mpath_revalidate_zones+0x106/0x1c0 drivers/nvme/host/multipath.c:301 nvme_update_ns_info+0x984/0x1200 drivers/nvme/host/core.c:2622 nvme_alloc_ns drivers/nvme/host/core.c:4284 [inline] nvme_scan_ns+0x2563/0x3640 drivers/nvme/host/core.c:4471 async_run_entry_fn+0x9d/0x430 kernel/async.c:129 process_one_work kernel/workqueue.c:3399 [inline] process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3482 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3563 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 -> #1 (&q->q_usage_counter(io)#77){++++}-{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:4043 [inline] nvme_init_ns_head drivers/nvme/host/core.c:4144 [inline] nvme_alloc_ns drivers/nvme/host/core.c:4258 [inline] nvme_scan_ns+0x1e0f/0x3640 drivers/nvme/host/core.c:4471 async_run_entry_fn+0x9d/0x430 kernel/async.c:129 process_one_work kernel/workqueue.c:3399 [inline] process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3482 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3563 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 -> #0 (fs_reclaim){+.+.}-{0:0}: 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 __fs_reclaim_acquire mm/page_alloc.c:4357 [inline] fs_reclaim_acquire+0x71/0x100 mm/page_alloc.c:4371 might_alloc include/linux/sched/mm.h:316 [inline] slab_pre_alloc_hook mm/slub.c:4636 [inline] slab_alloc_node mm/slub.c:4974 [inline] __do_kmalloc_node mm/slub.c:5418 [inline] __kmalloc_noprof+0xbc/0x710 mm/slub.c:5444 _kmalloc_noprof include/linux/slab.h:995 [inline] sd_read_block_zero drivers/scsi/sd.c:3749 [inline] sd_revalidate_disk+0x177d/0xb350 drivers/scsi/sd.c:3817 sd_probe+0x9f3/0x1180 drivers/scsi/sd.c:4101 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x254/0xae0 drivers/base/dd.c:706 __driver_probe_device+0x1e8/0x360 drivers/base/dd.c:868 driver_probe_device+0x4f/0x240 drivers/base/dd.c:898 __device_attach_driver+0x270/0x410 drivers/base/dd.c:1026 bus_for_each_drv+0x258/0x2f0 drivers/base/bus.c:500 __device_attach_async_helper+0x1e7/0x2b0 drivers/base/dd.c:1055 async_run_entry_fn+0x9d/0x430 kernel/async.c:129 process_one_work kernel/workqueue.c:3399 [inline] process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3482 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3563 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: fs_reclaim --> &q->q_usage_counter(io)#77 --> &q->limits_lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&q->limits_lock); lock(&q->q_usage_counter(io)#77); lock(&q->limits_lock); lock(fs_reclaim); *** DEADLOCK *** locks held by kworker/u8:3/49: 4, last CPU#0: #0: ffff88801bedc940 ((wq_completion)async){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffff88801bedc940 ((wq_completion)async){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffff88801bedc940 ((wq_completion)async){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3364 [inline] #0: ffff88801bedc940 ((wq_completion)async){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3482 #1: ffffc90000ba7c40 ((work_completion)(&entry->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffc90000ba7c40 ((work_completion)(&entry->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffc90000ba7c40 ((work_completion)(&entry->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3364 [inline] #1: ffffc90000ba7c40 ((work_completion)(&entry->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3482 #2: ffff888075d823c0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #2: ffff888075d823c0 (&dev->mutex){....}-{4:4}, at: __device_attach_async_helper+0xa4/0x2b0 drivers/base/dd.c:1041 #3: ffff888012ece3b8 (&q->limits_lock){+.+.}-{4:4}, at: queue_limits_start_update include/linux/blkdev.h:1101 [inline] #3: ffff888012ece3b8 (&q->limits_lock){+.+.}-{4:4}, at: sd_revalidate_disk+0xb88/0xb350 drivers/scsi/sd.c:3803 stack backtrace: CPU: 0 UID: 0 PID: 49 Comm: kworker/u8:3 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP 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 __fs_reclaim_acquire mm/page_alloc.c:4357 [inline] fs_reclaim_acquire+0x71/0x100 mm/page_alloc.c:4371 might_alloc include/linux/sched/mm.h:316 [inline] slab_pre_alloc_hook mm/slub.c:4636 [inline] slab_alloc_node mm/slub.c:4974 [inline] __do_kmalloc_node mm/slub.c:5418 [inline] __kmalloc_noprof+0xbc/0x710 mm/slub.c:5444 _kmalloc_noprof include/linux/slab.h:995 [inline] sd_read_block_zero drivers/scsi/sd.c:3749 [inline] sd_revalidate_disk+0x177d/0xb350 drivers/scsi/sd.c:3817 sd_probe+0x9f3/0x1180 drivers/scsi/sd.c:4101 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x254/0xae0 drivers/base/dd.c:706 __driver_probe_device+0x1e8/0x360 drivers/base/dd.c:868 driver_probe_device+0x4f/0x240 drivers/base/dd.c:898 __device_attach_driver+0x270/0x410 drivers/base/dd.c:1026 bus_for_each_drv+0x258/0x2f0 drivers/base/bus.c:500 __device_attach_async_helper+0x1e7/0x2b0 drivers/base/dd.c:1055 async_run_entry_fn+0x9d/0x430 kernel/async.c:129 process_one_work kernel/workqueue.c:3399 [inline] process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3482 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3563 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 sd 1:0:0:0: [sdb] 0 512-byte logical blocks: (0 B/0 B) sd 1:0:0:0: [sdb] 0-byte physical blocks sd 1:0:0:0: [sdb] Write Protect is off sd 1:0:0:0: [sdb] Mode Sense: 00 00 00 00 sd 1:0:0:0: [sdb] Asking for cache data failed sd 1:0:0:0: [sdb] Assuming drive cache: write through sd 1:0:0:0: [sdb] Attached SCSI removable disk