Hello, syzbot found the following issue on: HEAD commit: c88416ba074a Add linux-next specific files for 20241101 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=165f0740580000 kernel config: https://syzkaller.appspot.com/x/.config?x=704b6be2ac2f205f dashboard link: https://syzkaller.appspot.com/bug?extid=566d48f3784973a22771 compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/760a8c88d0c3/disk-c88416ba.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/46e4b0a851a2/vmlinux-c88416ba.xz kernel image: https://storage.googleapis.com/syzbot-assets/428e2c784b75/bzImage-c88416ba.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+566d48f3784973a22771@xxxxxxxxxxxxxxxxxxxxxxxxx ====================================================== WARNING: possible circular locking dependency detected 6.12.0-rc5-next-20241101-syzkaller #0 Not tainted ------------------------------------------------------ kworker/1:5/15509 is trying to acquire lock: ffff8880315343e0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] ffff8880315343e0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] ffff8880315343e0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: start_flush_work kernel/workqueue.c:4123 [inline] ffff8880315343e0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: __flush_work+0xe7/0xc50 kernel/workqueue.c:4181 but task is already holding lock: ffff888028c4eb70 (&q->q_usage_counter(queue)#52){++++}-{0:0}, at: sd_remove+0x8d/0x110 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)#52){++++}-{0:0}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 blk_queue_enter+0xe1/0x600 block/blk-core.c:328 blk_mq_alloc_request+0x26b/0xab0 block/blk-mq.c:626 scsi_alloc_request drivers/scsi/scsi_lib.c:1222 [inline] scsi_execute_cmd+0x177/0x1090 drivers/scsi/scsi_lib.c:304 read_capacity_10+0x256/0x9c0 drivers/scsi/sd.c:2766 sd_read_capacity drivers/scsi/sd.c:2834 [inline] sd_revalidate_disk+0x106c/0xbcf0 drivers/scsi/sd.c:3734 sd_probe+0x9fa/0x1100 drivers/scsi/sd.c:4010 really_probe+0x2b8/0xad0 drivers/base/dd.c:658 __driver_probe_device+0x1a2/0x390 drivers/base/dd.c:800 driver_probe_device+0x50/0x430 drivers/base/dd.c:830 __device_attach_driver+0x2d6/0x530 drivers/base/dd.c:958 bus_for_each_drv+0x24e/0x2e0 drivers/base/bus.c:459 __device_attach_async_helper+0x22d/0x300 drivers/base/dd.c:987 async_run_entry_fn+0xa8/0x420 kernel/async.c:129 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/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}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x1ac/0xee0 kernel/locking/mutex.c:735 queue_limits_start_update include/linux/blkdev.h:940 [inline] loop_reconfigure_limits+0x287/0xa70 drivers/block/loop.c:1004 loop_set_block_size drivers/block/loop.c:1474 [inline] lo_simple_ioctl drivers/block/loop.c:1497 [inline] lo_ioctl+0x1351/0x1f50 drivers/block/loop.c:1560 blkdev_ioctl+0x57d/0x6a0 block/ioctl.c:693 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0xf9/0x170 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (&q->q_usage_counter(io)#17){++++}-{0:0}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 bio_queue_enter block/blk.h:75 [inline] blk_mq_submit_bio+0x1510/0x2490 block/blk-mq.c:3069 __submit_bio+0x2c2/0x560 block/blk-core.c:629 __submit_bio_noacct_mq block/blk-core.c:710 [inline] submit_bio_noacct_nocheck+0x4d3/0xe30 block/blk-core.c:739 __block_write_full_folio+0x7ed/0xf50 fs/buffer.c:1904 write_cache_pages+0xd0/0x230 mm/page-writeback.c:2659 blkdev_writepages+0xb1/0x110 block/fops.c:433 do_writepages+0x35d/0x870 mm/page-writeback.c:2702 __writeback_single_inode+0x14f/0x10d0 fs/fs-writeback.c:1656 writeback_sb_inodes+0x80c/0x1370 fs/fs-writeback.c:1952 __writeback_inodes_wb+0x11b/0x260 fs/fs-writeback.c:2023 wb_writeback+0x42f/0xbd0 fs/fs-writeback.c:2134 wb_check_background_flush fs/fs-writeback.c:2204 [inline] wb_do_writeback fs/fs-writeback.c:2292 [inline] wb_workfn+0xc58/0x1090 fs/fs-writeback.c:2319 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/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+0x18ef/0x5920 kernel/locking/lockdep.c:3904 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 touch_work_lockdep_map kernel/workqueue.c:3895 [inline] start_flush_work kernel/workqueue.c:4149 [inline] __flush_work+0x74e/0xc50 kernel/workqueue.c:4181 flush_work kernel/workqueue.c:4238 [inline] flush_delayed_work+0x169/0x1c0 kernel/workqueue.c:4260 wb_shutdown+0x186/0x1e0 mm/backing-dev.c:575 bdi_unregister+0x19a/0x5d0 mm/backing-dev.c:1158 del_gendisk+0x400/0x930 block/genhd.c:707 sd_remove+0x8d/0x110 drivers/scsi/sd.c:4072 device_remove drivers/base/dd.c:569 [inline] __device_release_driver drivers/base/dd.c:1273 [inline] device_release_driver_internal+0x503/0x7c0 drivers/base/dd.c:1296 bus_remove_device+0x34f/0x420 drivers/base/bus.c:576 device_del+0x57a/0x9b0 drivers/base/core.c:3861 __scsi_remove_device+0x1ad/0x3c0 drivers/scsi/scsi_sysfs.c:1499 scsi_forget_host+0xcf/0x110 drivers/scsi/scsi_scan.c:2068 scsi_remove_host+0x1dd/0x770 drivers/scsi/hosts.c:181 quiesce_and_remove_host drivers/usb/storage/usb.c:949 [inline] usb_stor_disconnect+0x14e/0x1f0 drivers/usb/storage/usb.c:1178 usb_unbind_interface+0x25e/0x940 drivers/usb/core/driver.c:461 device_remove drivers/base/dd.c:569 [inline] __device_release_driver drivers/base/dd.c:1273 [inline] device_release_driver_internal+0x503/0x7c0 drivers/base/dd.c:1296 bus_remove_device+0x34f/0x420 drivers/base/bus.c:576 device_del+0x57a/0x9b0 drivers/base/core.c:3861 usb_disable_device+0x3bf/0x850 drivers/usb/core/message.c:1418 usb_disconnect+0x340/0x950 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+0x1ebc/0x5150 drivers/usb/core/hub.c:5903 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/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)#52 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&q->q_usage_counter(queue)#52); lock(&q->limits_lock); lock(&q->q_usage_counter(queue)#52); lock((work_completion)(&(&wb->dwork)->work)); *** DEADLOCK *** 9 locks held by kworker/1:5/15509: #0: ffff888021e8bd48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff888021e8bd48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc900048f7d00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc900048f7d00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffff8881443c5190 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1014 [inline] #2: ffff8881443c5190 (&dev->mutex){....}-{4:4}, at: hub_event+0x1fe/0x5150 drivers/usb/core/hub.c:5849 #3: ffff88814d17f190 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1014 [inline] #3: ffff88814d17f190 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0x103/0x950 drivers/usb/core/hub.c:2295 #4: ffff88802484a160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1014 [inline] #4: ffff88802484a160 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1095 [inline] #4: ffff88802484a160 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xce/0x7c0 drivers/base/dd.c:1293 #5: ffff88806d2580e0 (&shost->scan_mutex){+.+.}-{4:4}, at: scsi_remove_host+0x34/0x770 drivers/scsi/hosts.c:169 #6: ffff88805966c378 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1014 [inline] #6: ffff88805966c378 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1095 [inline] #6: ffff88805966c378 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xce/0x7c0 drivers/base/dd.c:1293 #7: ffff888028c4eb70 (&q->q_usage_counter(queue)#52){++++}-{0:0}, at: sd_remove+0x8d/0x110 drivers/scsi/sd.c:4072 #8: ffffffff8e939ee0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #8: ffffffff8e939ee0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #8: ffffffff8e939ee0 (rcu_read_lock){....}-{1:3}, at: start_flush_work kernel/workqueue.c:4123 [inline] #8: ffffffff8e939ee0 (rcu_read_lock){....}-{1:3}, at: __flush_work+0xe7/0xc50 kernel/workqueue.c:4181 stack backtrace: CPU: 1 UID: 0 PID: 15509 Comm: kworker/1:5 Not tainted 6.12.0-rc5-next-20241101-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: usb_hub_wq hub_event Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2074 check_noncircular+0x36a/0x4a0 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+0x18ef/0x5920 kernel/locking/lockdep.c:3904 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 touch_work_lockdep_map kernel/workqueue.c:3895 [inline] start_flush_work kernel/workqueue.c:4149 [inline] __flush_work+0x74e/0xc50 kernel/workqueue.c:4181 flush_work kernel/workqueue.c:4238 [inline] flush_delayed_work+0x169/0x1c0 kernel/workqueue.c:4260 wb_shutdown+0x186/0x1e0 mm/backing-dev.c:575 bdi_unregister+0x19a/0x5d0 mm/backing-dev.c:1158 del_gendisk+0x400/0x930 block/genhd.c:707 sd_remove+0x8d/0x110 drivers/scsi/sd.c:4072 device_remove drivers/base/dd.c:569 [inline] __device_release_driver drivers/base/dd.c:1273 [inline] device_release_driver_internal+0x503/0x7c0 drivers/base/dd.c:1296 bus_remove_device+0x34f/0x420 drivers/base/bus.c:576 device_del+0x57a/0x9b0 drivers/base/core.c:3861 __scsi_remove_device+0x1ad/0x3c0 drivers/scsi/scsi_sysfs.c:1499 scsi_forget_host+0xcf/0x110 drivers/scsi/scsi_scan.c:2068 scsi_remove_host+0x1dd/0x770 drivers/scsi/hosts.c:181 quiesce_and_remove_host drivers/usb/storage/usb.c:949 [inline] usb_stor_disconnect+0x14e/0x1f0 drivers/usb/storage/usb.c:1178 usb_unbind_interface+0x25e/0x940 drivers/usb/core/driver.c:461 device_remove drivers/base/dd.c:569 [inline] __device_release_driver drivers/base/dd.c:1273 [inline] device_release_driver_internal+0x503/0x7c0 drivers/base/dd.c:1296 bus_remove_device+0x34f/0x420 drivers/base/bus.c:576 device_del+0x57a/0x9b0 drivers/base/core.c:3861 usb_disable_device+0x3bf/0x850 drivers/usb/core/message.c:1418 usb_disconnect+0x340/0x950 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+0x1ebc/0x5150 drivers/usb/core/hub.c:5903 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 </TASK> --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup
