====================================================== WARNING: possible circular locking dependency detected 6.12.0-syzkaller-01782-gbf9aa14fc523 #0 Not tainted ------------------------------------------------------ kworker/2:5/8627 is trying to acquire lock: ffff888107028aa8 (&q->q_usage_counter(queue)#51){++++}-{0:0}, at: blk_mq_alloc_request+0x59b/0x950 block/blk-mq.c:652 but task is already holding lock: ffff8881070290c0 (&q->limits_lock){+.+.}-{4:4}, at: queue_limits_start_update include/linux/blkdev.h:945 [inline] ffff8881070290c0 (&q->limits_lock){+.+.}-{4:4}, at: sd_revalidate_disk.isra.0+0x52c/0xa8d0 drivers/scsi/sd.c:3727 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #5 (&q->limits_lock){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x19b/0xa60 kernel/locking/mutex.c:735 queue_limits_start_update include/linux/blkdev.h:945 [inline] __nbd_set_size+0x2c0/0x730 drivers/block/nbd.c:351 nbd_set_size drivers/block/nbd.c:388 [inline] nbd_start_device+0x8fd/0xd70 drivers/block/nbd.c:1456 nbd_start_device_ioctl drivers/block/nbd.c:1464 [inline] __nbd_ioctl drivers/block/nbd.c:1539 [inline] nbd_ioctl+0x21a/0xfd0 drivers/block/nbd.c:1579 blkdev_ioctl+0x276/0x6d0 block/ioctl.c:693 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl fs/ioctl.c:892 [inline] __x64_sys_ioctl+0x190/0x200 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #4 (&q->q_usage_counter(io)#51){++++}-{0:0}: bio_queue_enter block/blk.h:75 [inline] blk_mq_submit_bio+0x1fc4/0x24c0 block/blk-mq.c:3092 __submit_bio+0x384/0x540 block/blk-core.c:629 __submit_bio_noacct_mq block/blk-core.c:710 [inline] submit_bio_noacct_nocheck+0x6fb/0xd70 block/blk-core.c:739 submit_bio_noacct+0x93a/0x1e10 block/blk-core.c:868 submit_bh fs/buffer.c:2825 [inline] block_read_full_folio+0x812/0xa50 fs/buffer.c:2452 filemap_read_folio+0xc6/0x2a0 mm/filemap.c:2367 filemap_update_page mm/filemap.c:2451 [inline] filemap_get_pages+0x1560/0x1be0 mm/filemap.c:2572 filemap_read+0x3ca/0xd70 mm/filemap.c:2647 blkdev_read_iter+0x187/0x480 block/fops.c:767 new_sync_read fs/read_write.c:484 [inline] vfs_read+0x87f/0xbe0 fs/read_write.c:565 ksys_read+0x12b/0x250 fs/read_write.c:708 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #3 (mapping.invalidate_lock#2){++++}-{4:4}: down_read+0x9a/0x330 kernel/locking/rwsem.c:1524 filemap_invalidate_lock_shared include/linux/fs.h:873 [inline] filemap_fault+0x2e2/0x2820 mm/filemap.c:3333 __do_fault+0x10a/0x490 mm/memory.c:4882 do_read_fault mm/memory.c:5297 [inline] do_fault mm/memory.c:5431 [inline] do_pte_missing+0xec5/0x3e70 mm/memory.c:3965 handle_pte_fault mm/memory.c:5766 [inline] __handle_mm_fault+0x100a/0x2a10 mm/memory.c:5909 handle_mm_fault+0x3fa/0xaa0 mm/memory.c:6077 do_user_addr_fault+0x7a3/0x13f0 arch/x86/mm/fault.c:1389 handle_page_fault arch/x86/mm/fault.c:1481 [inline] exc_page_fault+0x5c/0xc0 arch/x86/mm/fault.c:1539 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 do_strncpy_from_user lib/strncpy_from_user.c:41 [inline] strncpy_from_user+0x132/0x2c0 lib/strncpy_from_user.c:127 getname_flags.part.0+0x8f/0x550 fs/namei.c:150 getname_flags include/linux/audit.h:322 [inline] getname+0x8d/0xe0 fs/namei.c:223 do_sys_openat2+0x104/0x1e0 fs/open.c:1392 do_sys_open fs/open.c:1413 [inline] __do_sys_openat fs/open.c:1429 [inline] __se_sys_openat fs/open.c:1424 [inline] __x64_sys_openat+0x175/0x210 fs/open.c:1424 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #2 (&mm->mmap_lock){++++}-{4:4}: __might_fault mm/memory.c:6716 [inline] __might_fault+0x11b/0x190 mm/memory.c:6709 _inline_copy_from_user include/linux/uaccess.h:162 [inline] _copy_from_user+0x29/0xd0 lib/usercopy.c:18 copy_from_user include/linux/uaccess.h:212 [inline] __blk_trace_setup+0xa8/0x180 kernel/trace/blktrace.c:626 blk_trace_ioctl+0x163/0x290 kernel/trace/blktrace.c:740 blkdev_ioctl+0x109/0x6d0 block/ioctl.c:682 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl fs/ioctl.c:892 [inline] __x64_sys_ioctl+0x190/0x200 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (&q->debugfs_mutex){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x19b/0xa60 kernel/locking/mutex.c:735 blk_mq_init_sched+0x42b/0x640 block/blk-mq-sched.c:473 elevator_init_mq+0x2cd/0x420 block/elevator.c:610 add_disk_fwnode+0x113/0x1300 block/genhd.c:413 sd_probe+0xa86/0x1000 drivers/scsi/sd.c:4024 call_driver_probe drivers/base/dd.c:579 [inline] really_probe+0x23e/0xa90 drivers/base/dd.c:658 __driver_probe_device+0x1de/0x440 drivers/base/dd.c:800 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:830 __device_attach_driver+0x1df/0x310 drivers/base/dd.c:958 bus_for_each_drv+0x157/0x1e0 drivers/base/bus.c:459 __device_attach_async_helper+0x1d3/0x290 drivers/base/dd.c:987 async_run_entry_fn+0x9c/0x530 kernel/async.c:129 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3229 process_scheduled_works kernel/workqueue.c:3310 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 -> #0 (&q->q_usage_counter(queue)#51){++++}-{0:0}: check_prev_add kernel/locking/lockdep.c:3161 [inline] check_prevs_add kernel/locking/lockdep.c:3280 [inline] validate_chain kernel/locking/lockdep.c:3904 [inline] __lock_acquire+0x249e/0x3c40 kernel/locking/lockdep.c:5226 lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5849 blk_queue_enter+0x50f/0x640 block/blk-core.c:328 blk_mq_alloc_request+0x59b/0x950 block/blk-mq.c:652 scsi_alloc_request drivers/scsi/scsi_lib.c:1222 [inline] scsi_execute_cmd+0x1eb/0xf40 drivers/scsi/scsi_lib.c:304 read_capacity_16+0x213/0xe10 drivers/scsi/sd.c:2655 sd_read_capacity drivers/scsi/sd.c:2824 [inline] sd_revalidate_disk.isra.0+0x1a06/0xa8d0 drivers/scsi/sd.c:3734 scsi_rescan_device+0x243/0x340 drivers/scsi/scsi_scan.c:1715 ata_scsi_dev_rescan+0x1cb/0x470 drivers/ata/libata-scsi.c:4902 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3229 process_scheduled_works kernel/workqueue.c:3310 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 other info that might help us debug this: Chain exists of: &q->q_usage_counter(queue)#51 --> &q->q_usage_counter(io)#51 --> &q->limits_lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&q->limits_lock); lock(&q->q_usage_counter(io)#51); lock(&q->limits_lock); rlock(&q->q_usage_counter(queue)#51); *** DEADLOCK *** 5 locks held by kworker/2:5/8627: #0: ffff88801b088948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x129b/0x1ba0 kernel/workqueue.c:3204 #1: ffffc90003cb7d80 ((work_completion)(&(&ap->scsi_rescan_task)->work)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3205 #2: ffff888027324358 (&ap->scsi_scan_mutex){+.+.}-{4:4}, at: ata_scsi_dev_rescan+0x3e/0x470 drivers/ata/libata-scsi.c:4874 #3: ffff888107dda378 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1014 [inline] #3: ffff888107dda378 (&dev->mutex){....}-{4:4}, at: scsi_rescan_device+0x27/0x340 drivers/scsi/scsi_scan.c:1691 #4: ffff8881070290c0 (&q->limits_lock){+.+.}-{4:4}, at: queue_limits_start_update include/linux/blkdev.h:945 [inline] #4: ffff8881070290c0 (&q->limits_lock){+.+.}-{4:4}, at: sd_revalidate_disk.isra.0+0x52c/0xa8d0 drivers/scsi/sd.c:3727 stack backtrace: CPU: 2 UID: 0 PID: 8627 Comm: kworker/2:5 Not tainted 6.12.0-syzkaller-01782-gbf9aa14fc523 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Workqueue: events ata_scsi_dev_rescan Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_circular_bug+0x419/0x5d0 kernel/locking/lockdep.c:2074 check_noncircular+0x31a/0x400 kernel/locking/lockdep.c:2206 check_prev_add kernel/locking/lockdep.c:3161 [inline] check_prevs_add kernel/locking/lockdep.c:3280 [inline] validate_chain kernel/locking/lockdep.c:3904 [inline] __lock_acquire+0x249e/0x3c40 kernel/locking/lockdep.c:5226 lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5849 blk_queue_enter+0x50f/0x640 block/blk-core.c:328 blk_mq_alloc_request+0x59b/0x950 block/blk-mq.c:652 scsi_alloc_request drivers/scsi/scsi_lib.c:1222 [inline] scsi_execute_cmd+0x1eb/0xf40 drivers/scsi/scsi_lib.c:304 read_capacity_16+0x213/0xe10 drivers/scsi/sd.c:2655 sd_read_capacity drivers/scsi/sd.c:2824 [inline] sd_revalidate_disk.isra.0+0x1a06/0xa8d0 drivers/scsi/sd.c:3734 scsi_rescan_device+0x243/0x340 drivers/scsi/scsi_scan.c:1715 ata_scsi_dev_rescan+0x1cb/0x470 drivers/ata/libata-scsi.c:4902 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3229 process_scheduled_works kernel/workqueue.c:3310 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244