====================================================== WARNING: possible circular locking dependency detected 5.17.0-rc6-next-20220301-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.1/3632 is trying to acquire lock: ffff88801f712138 ((wq_completion)loop1){+.+.}-{0:0}, at: flush_workqueue+0x135/0x1440 kernel/workqueue.c:2828 but task is already holding lock: ffff88801b8b8118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0x99/0x950 block/bdev.c:905 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #6 (&disk->open_mutex){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:600 [inline] __mutex_lock+0x12f/0x12f0 kernel/locking/mutex.c:733 blkdev_get_by_dev.part.0+0x482/0xc90 block/bdev.c:807 blkdev_get_by_dev+0x6b/0x80 block/bdev.c:850 swsusp_check+0x97/0x420 kernel/power/swap.c:1524 software_resume.part.0+0x161/0x240 kernel/power/hibernate.c:980 software_resume kernel/power/hibernate.c:85 [inline] resume_store+0x161/0x190 kernel/power/hibernate.c:1182 kobj_attr_store+0x50/0x80 lib/kobject.c:856 sysfs_kf_write+0x110/0x160 fs/sysfs/file.c:136 kernfs_fop_write_iter+0x3f8/0x610 fs/kernfs/file.c:291 call_write_iter include/linux/fs.h:2102 [inline] new_sync_write+0x431/0x660 fs/read_write.c:504 vfs_write+0x7c9/0xad0 fs/read_write.c:591 ksys_write+0x12d/0x250 fs/read_write.c:644 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae -> #5 (system_transition_mutex/1){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:600 [inline] __mutex_lock+0x12f/0x12f0 kernel/locking/mutex.c:733 software_resume.part.0+0x19/0x240 kernel/power/hibernate.c:935 software_resume kernel/power/hibernate.c:85 [inline] resume_store+0x161/0x190 kernel/power/hibernate.c:1182 kobj_attr_store+0x50/0x80 lib/kobject.c:856 sysfs_kf_write+0x110/0x160 fs/sysfs/file.c:136 kernfs_fop_write_iter+0x3f8/0x610 fs/kernfs/file.c:291 call_write_iter include/linux/fs.h:2102 [inline] new_sync_write+0x431/0x660 fs/read_write.c:504 vfs_write+0x7c9/0xad0 fs/read_write.c:591 ksys_write+0x12d/0x250 fs/read_write.c:644 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae -> #4 (&of->mutex){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:600 [inline] __mutex_lock+0x12f/0x12f0 kernel/locking/mutex.c:733 kernfs_seq_start+0x47/0x440 fs/kernfs/file.c:112 seq_read_iter+0x2c6/0x1280 fs/seq_file.c:225 kernfs_fop_read_iter+0x514/0x6f0 fs/kernfs/file.c:236 call_read_iter include/linux/fs.h:2096 [inline] new_sync_read+0x429/0x6e0 fs/read_write.c:401 vfs_read+0x49b/0x5e0 fs/read_write.c:482 ksys_read+0x12d/0x250 fs/read_write.c:620 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae -> #3 (&p->lock){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:600 [inline] __mutex_lock+0x12f/0x12f0 kernel/locking/mutex.c:733 seq_read_iter+0xdf/0x1280 fs/seq_file.c:182 call_read_iter include/linux/fs.h:2096 [inline] generic_file_splice_read+0x45b/0x6d0 fs/splice.c:311 do_splice_to+0x1bf/0x250 fs/splice.c:796 splice_direct_to_actor+0x2c2/0x8c0 fs/splice.c:870 do_splice_direct+0x1b3/0x280 fs/splice.c:979 do_sendfile+0xaf2/0x1250 fs/read_write.c:1246 __do_sys_sendfile64 fs/read_write.c:1311 [inline] __se_sys_sendfile64 fs/read_write.c:1297 [inline] __x64_sys_sendfile64+0x1cc/0x210 fs/read_write.c:1297 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae -> #2 (sb_writers#5){.+.+}-{0:0}: percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1730 [inline] sb_start_write include/linux/fs.h:1805 [inline] file_start_write include/linux/fs.h:2856 [inline] lo_write_bvec drivers/block/loop.c:244 [inline] lo_write_simple drivers/block/loop.c:267 [inline] do_req_filebacked drivers/block/loop.c:494 [inline] loop_handle_cmd drivers/block/loop.c:1869 [inline] loop_process_work+0x1326/0x1da0 drivers/block/loop.c:1909 process_one_work+0x996/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e9/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 -> #1 ((work_completion)(&lo->rootcg_work)){+.+.}-{0:0}: process_one_work+0x905/0x1610 kernel/workqueue.c:2265 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e9/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 -> #0 ((wq_completion)loop1){+.+.}-{0:0}: check_prev_add kernel/locking/lockdep.c:3096 [inline] check_prevs_add kernel/locking/lockdep.c:3219 [inline] validate_chain kernel/locking/lockdep.c:3834 [inline] __lock_acquire+0x2ac6/0x56c0 kernel/locking/lockdep.c:5060 lock_acquire kernel/locking/lockdep.c:5672 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5637 flush_workqueue+0x164/0x1440 kernel/workqueue.c:2831 drain_workqueue+0x1a5/0x3c0 kernel/workqueue.c:2996 destroy_workqueue+0x71/0x800 kernel/workqueue.c:4433 __loop_clr_fd+0x1ab/0xe20 drivers/block/loop.c:1123 lo_release+0x1ac/0x1f0 drivers/block/loop.c:1755 blkdev_put_whole block/bdev.c:689 [inline] blkdev_put+0x2de/0x950 block/bdev.c:947 deactivate_locked_super+0x94/0x160 fs/super.c:332 deactivate_super+0xad/0xd0 fs/super.c:363 cleanup_mnt+0x3a2/0x540 fs/namespace.c:1171 task_work_run+0xdd/0x1a0 kernel/task_work.c:164 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_user_mode_loop kernel/entry/common.c:176 [inline] exit_to_user_mode_prepare+0x27e/0x290 kernel/entry/common.c:208 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:301 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae other info that might help us debug this: Chain exists of: (wq_completion)loop1 --> system_transition_mutex/1 --> &disk->open_mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&disk->open_mutex); lock(system_transition_mutex/1); lock(&disk->open_mutex); lock((wq_completion)loop1); *** DEADLOCK *** 1 lock held by syz-executor.1/3632: #0: ffff88801b8b8118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0x99/0x950 block/bdev.c:905 stack backtrace: CPU: 1 PID: 3632 Comm: syz-executor.1 Not tainted 5.17.0-rc6-next-20220301-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 check_noncircular+0x25f/0x2e0 kernel/locking/lockdep.c:2176 check_prev_add kernel/locking/lockdep.c:3096 [inline] check_prevs_add kernel/locking/lockdep.c:3219 [inline] validate_chain kernel/locking/lockdep.c:3834 [inline] __lock_acquire+0x2ac6/0x56c0 kernel/locking/lockdep.c:5060 lock_acquire kernel/locking/lockdep.c:5672 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5637 flush_workqueue+0x164/0x1440 kernel/workqueue.c:2831 drain_workqueue+0x1a5/0x3c0 kernel/workqueue.c:2996 destroy_workqueue+0x71/0x800 kernel/workqueue.c:4433 __loop_clr_fd+0x1ab/0xe20 drivers/block/loop.c:1123 lo_release+0x1ac/0x1f0 drivers/block/loop.c:1755 blkdev_put_whole block/bdev.c:689 [inline] blkdev_put+0x2de/0x950 block/bdev.c:947 deactivate_locked_super+0x94/0x160 fs/super.c:332 deactivate_super+0xad/0xd0 fs/super.c:363 cleanup_mnt+0x3a2/0x540 fs/namespace.c:1171 task_work_run+0xdd/0x1a0 kernel/task_work.c:164 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_user_mode_loop kernel/entry/common.c:176 [inline] exit_to_user_mode_prepare+0x27e/0x290 kernel/entry/common.c:208 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:301 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f04fb08a4b7 Code: ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffd35a64328 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f04fb08a4b7 RDX: 00007ffd35a643fb RSI: 000000000000000a RDI: 00007ffd35a643f0 RBP: 00007ffd35a643f0 R08: 00000000ffffffff R09: 00007ffd35a641c0 R10: 00005555563088b3 R11: 0000000000000246 R12: 00007f04fb0e21ea R13: 00007ffd35a654b0 R14: 0000555556308810 R15: 00007ffd35a654f0