====================================================== WARNING: possible circular locking dependency detected 6.13.0-rc1-syzkaller-00002-gcdd30ebb1b9f #0 Not tainted ------------------------------------------------------ kworker/0:2/970 is trying to acquire lock: ffff888032eca3e0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: touch_work_lockdep_map kernel/workqueue.c:3909 [inline] ffff888032eca3e0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: start_flush_work kernel/workqueue.c:4163 [inline] ffff888032eca3e0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: __flush_work+0x46d/0xc30 kernel/workqueue.c:4195 but task is already holding lock: ffff888028bc0aa8 (&q->q_usage_counter(queue)#53){++++}-{0:0}, at: sd_remove+0x8f/0x150 drivers/scsi/sd.c:4072 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&q->q_usage_counter(queue)#53){++++}-{0:0}: blk_queue_enter+0x50f/0x640 block/blk-core.c:328 blk_mq_alloc_request+0x59b/0x950 block/blk-mq.c:651 scsi_alloc_request drivers/scsi/scsi_lib.c:1222 [inline] scsi_execute_cmd+0x1eb/0xf40 drivers/scsi/scsi_lib.c:304 read_capacity_10+0x1d4/0x6d0 drivers/scsi/sd.c:2766 sd_read_capacity drivers/scsi/sd.c:2834 [inline] sd_revalidate_disk.isra.0+0x3145/0xa8d0 drivers/scsi/sd.c:3734 sd_probe+0x904/0x1000 drivers/scsi/sd.c:4010 call_driver_probe drivers/base/dd.c:579 [inline] really_probe+0x241/0xa90 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+0x15a/0x1e0 drivers/base/bus.c:459 __device_attach_async_helper+0x1d3/0x290 drivers/base/dd.c:987 async_run_entry_fn+0x9f/0x530 kernel/async.c:129 process_one_work+0x9c8/0x1ba0 kernel/workqueue.c:3229 process_scheduled_works kernel/workqueue.c:3310 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391 kthread+0x2c4/0x3a0 kernel/kthread.c:389 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 -> #2 (&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:949 [inline] loop_reconfigure_limits+0x407/0x8c0 drivers/block/loop.c:998 loop_set_block_size drivers/block/loop.c:1473 [inline] lo_simple_ioctl drivers/block/loop.c:1496 [inline] lo_ioctl+0x901/0x18b0 drivers/block/loop.c:1559 blkdev_ioctl+0x279/0x6d0 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+0x193/0x200 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->q_usage_counter(io)#24){++++}-{0:0}: bio_queue_enter block/blk.h:75 [inline] blk_mq_submit_bio+0x1fb6/0x24c0 block/blk-mq.c:3091 __submit_bio+0x384/0x540 block/blk-core.c:629 __submit_bio_noacct_mq block/blk-core.c:710 [inline] submit_bio_noacct_nocheck+0x698/0xd70 block/blk-core.c:739 submit_bio_noacct+0x93a/0x1e20 block/blk-core.c:868 __block_write_full_folio+0x729/0xe00 fs/buffer.c:1904 block_write_full_folio+0x342/0x400 fs/buffer.c:2743 write_cache_pages+0xb3/0x130 mm/page-writeback.c:2659 blkdev_writepages+0xa6/0xf0 block/fops.c:433 do_writepages+0x1b6/0x820 mm/page-writeback.c:2702 __writeback_single_inode+0x166/0xfa0 fs/fs-writeback.c:1680 writeback_sb_inodes+0x606/0xfa0 fs/fs-writeback.c:1976 __writeback_inodes_wb+0xff/0x2e0 fs/fs-writeback.c:2047 wb_writeback+0x803/0xb80 fs/fs-writeback.c:2158 wb_check_background_flush fs/fs-writeback.c:2228 [inline] wb_do_writeback fs/fs-writeback.c:2316 [inline] wb_workfn+0x730/0xbc0 fs/fs-writeback.c:2343 process_one_work+0x9c8/0x1ba0 kernel/workqueue.c:3229 process_scheduled_works kernel/workqueue.c:3310 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391 kthread+0x2c4/0x3a0 kernel/kthread.c:389 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 -> #0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{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 touch_work_lockdep_map kernel/workqueue.c:3909 [inline] start_flush_work kernel/workqueue.c:4163 [inline] __flush_work+0x477/0xc30 kernel/workqueue.c:4195 wb_shutdown+0x180/0x240 mm/backing-dev.c:575 bdi_unregister+0x184/0x640 mm/backing-dev.c:1158 del_gendisk+0x947/0xb20 block/genhd.c:707 sd_remove+0x8f/0x150 drivers/scsi/sd.c:4072 device_remove drivers/base/dd.c:569 [inline] device_remove+0x125/0x170 drivers/base/dd.c:561 __device_release_driver drivers/base/dd.c:1273 [inline] device_release_driver_internal+0x44a/0x610 drivers/base/dd.c:1296 bus_remove_device+0x22f/0x420 drivers/base/bus.c:576 device_del+0x396/0x9f0 drivers/base/core.c:3854 __scsi_remove_device+0x307/0x3d0 drivers/scsi/scsi_sysfs.c:1499 scsi_forget_host+0x138/0x190 drivers/scsi/scsi_scan.c:2068 scsi_remove_host+0xf8/0x320 drivers/scsi/hosts.c:181 quiesce_and_remove_host drivers/usb/storage/usb.c:949 [inline] usb_stor_disconnect+0x121/0x270 drivers/usb/storage/usb.c:1178 usb_unbind_interface+0x1e5/0x960 drivers/usb/core/driver.c:458 device_remove drivers/base/dd.c:569 [inline] device_remove+0x125/0x170 drivers/base/dd.c:561 __device_release_driver drivers/base/dd.c:1273 [inline] device_release_driver_internal+0x44a/0x610 drivers/base/dd.c:1296 bus_remove_device+0x22f/0x420 drivers/base/bus.c:576 device_del+0x396/0x9f0 drivers/base/core.c:3854 usb_disable_device+0x36c/0x7f0 drivers/usb/core/message.c:1418 usb_disconnect+0x2e1/0x920 drivers/usb/core/hub.c:2304 hub_port_connect drivers/usb/core/hub.c:5361 [inline] hub_port_connect_change drivers/usb/core/hub.c:5661 [inline] port_event drivers/usb/core/hub.c:5821 [inline] hub_event+0x1da5/0x4e10 drivers/usb/core/hub.c:5903 process_one_work+0x9c8/0x1ba0 kernel/workqueue.c:3229 process_scheduled_works kernel/workqueue.c:3310 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391 kthread+0x2c4/0x3a0 kernel/kthread.c:389 ret_from_fork+0x48/0x80 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: (work_completion)(&(&wb->dwork)->work) --> &q->limits_lock --> &q->q_usage_counter(queue)#53 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&q->q_usage_counter(queue)#53); lock(&q->limits_lock); lock(&q->q_usage_counter(queue)#53); lock((work_completion)(&(&wb->dwork)->work)); *** DEADLOCK *** 9 locks held by kworker/0:2/970: #0: ffff8881412c8d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3204 #1: ffffc90003d5fd80 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3205 #2: ffff888028c83190 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1014 [inline] #2: ffff888028c83190 (&dev->mutex){....}-{4:4}, at: hub_event+0x1c1/0x4e10 drivers/usb/core/hub.c:5849 #3: ffff88805e343190 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1014 [inline] #3: ffff88805e343190 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0x10a/0x920 drivers/usb/core/hub.c:2295 #4: ffff88807dc73160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1014 [inline] #4: ffff88807dc73160 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1095 [inline] #4: ffff88807dc73160 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xa4/0x610 drivers/base/dd.c:1293 #5: ffff88805e1280e0 (&shost->scan_mutex){+.+.}-{4:4}, at: scsi_remove_host+0x26/0x320 drivers/scsi/hosts.c:169 #6: ffff88805b12c378 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1014 [inline] #6: ffff88805b12c378 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1095 [inline] #6: ffff88805b12c378 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xa4/0x610 drivers/base/dd.c:1293 #7: ffff888028bc0aa8 (&q->q_usage_counter(queue)#53){++++}-{0:0}, at: sd_remove+0x8f/0x150 drivers/scsi/sd.c:4072 #8: ffffffff8e1bb500 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #8: ffffffff8e1bb500 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #8: ffffffff8e1bb500 (rcu_read_lock){....}-{1:3}, at: start_flush_work kernel/workqueue.c:4137 [inline] #8: ffffffff8e1bb500 (rcu_read_lock){....}-{1:3}, at: __flush_work+0x103/0xc30 kernel/workqueue.c:4195 stack backtrace: CPU: 0 UID: 0 PID: 970 Comm: kworker/0:2 Not tainted 6.13.0-rc1-syzkaller-00002-gcdd30ebb1b9f #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: usb_hub_wq hub_event 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 touch_work_lockdep_map kernel/workqueue.c:3909 [inline] start_flush_work kernel/workqueue.c:4163 [inline] __flush_work+0x477/0xc30 kernel/workqueue.c:4195 wb_shutdown+0x180/0x240 mm/backing-dev.c:575 bdi_unregister+0x184/0x640 mm/backing-dev.c:1158 del_gendisk+0x947/0xb20 block/genhd.c:707 sd_remove+0x8f/0x150 drivers/scsi/sd.c:4072 device_remove drivers/base/dd.c:569 [inline] device_remove+0x125/0x170 drivers/base/dd.c:561 __device_release_driver drivers/base/dd.c:1273 [inline] device_release_driver_internal+0x44a/0x610 drivers/base/dd.c:1296 bus_remove_device+0x22f/0x420 drivers/base/bus.c:576 device_del+0x396/0x9f0 drivers/base/core.c:3854 __scsi_remove_device+0x307/0x3d0 drivers/scsi/scsi_sysfs.c:1499 scsi_forget_host+0x138/0x190 drivers/scsi/scsi_scan.c:2068 scsi_remove_host+0xf8/0x320 drivers/scsi/hosts.c:181 quiesce_and_remove_host drivers/usb/storage/usb.c:949 [inline] usb_stor_disconnect+0x121/0x270 drivers/usb/storage/usb.c:1178 usb_unbind_interface+0x1e5/0x960 drivers/usb/core/driver.c:458 device_remove drivers/base/dd.c:569 [inline] device_remove+0x125/0x170 drivers/base/dd.c:561 __device_release_driver drivers/base/dd.c:1273 [inline] device_release_driver_internal+0x44a/0x610 drivers/base/dd.c:1296 bus_remove_device+0x22f/0x420 drivers/base/bus.c:576 device_del+0x396/0x9f0 drivers/base/core.c:3854 usb_disable_device+0x36c/0x7f0 drivers/usb/core/message.c:1418 usb_disconnect+0x2e1/0x920 drivers/usb/core/hub.c:2304 hub_port_connect drivers/usb/core/hub.c:5361 [inline] hub_port_connect_change drivers/usb/core/hub.c:5661 [inline] port_event drivers/usb/core/hub.c:5821 [inline] hub_event+0x1da5/0x4e10 drivers/usb/core/hub.c:5903 process_one_work+0x9c8/0x1ba0 kernel/workqueue.c:3229 process_scheduled_works kernel/workqueue.c:3310 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391 kthread+0x2c4/0x3a0 kernel/kthread.c:389 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244