====================================================== WARNING: possible circular locking dependency detected 5.17.0-rc6-syzkaller-00226-g07ebd38a0da2 #0 Not tainted ------------------------------------------------------ syz-executor.1/3672 is trying to acquire lock: ffff88804d15f138 ((wq_completion)loop1){+.+.}-{0:0}, at: flush_workqueue+0xe1/0x13a0 kernel/workqueue.c:2824 but task is already holding lock: ffff8880183a4118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0x99/0x950 block/bdev.c:902 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #7 (&disk->open_mutex){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:600 [inline] __mutex_lock+0x12f/0x12f0 kernel/locking/mutex.c:733 bd_register_pending_holders+0x2c/0x470 block/holder.c:161 device_add_disk+0x6bb/0xd70 block/genhd.c:493 add_disk include/linux/genhd.h:169 [inline] loop_add+0x71e/0x900 drivers/block/loop.c:2046 loop_probe+0x6a/0x80 drivers/block/loop.c:2091 blk_request_module+0x111/0x1d0 block/genhd.c:704 blkdev_get_no_open+0x74/0x90 block/bdev.c:737 blkdev_get_by_dev.part.0+0x22/0xc70 block/bdev.c:791 blkdev_get_by_dev+0x6b/0x80 block/bdev.c:847 blkdev_open+0x154/0x2e0 block/fops.c:503 do_dentry_open+0x4b9/0x1250 fs/open.c:824 do_open fs/namei.c:3476 [inline] path_openat+0x1c9e/0x2940 fs/namei.c:3609 do_filp_open+0x1aa/0x400 fs/namei.c:3636 do_sys_openat2+0x16d/0x4d0 fs/open.c:1214 do_sys_open fs/open.c:1230 [inline] __do_compat_sys_open fs/open.c:1281 [inline] __se_compat_sys_open fs/open.c:1279 [inline] __ia32_compat_sys_open+0x119/0x1c0 fs/open.c:1279 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0x65/0xf0 arch/x86/entry/common.c:178 do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c -> #6 (major_names_lock){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:600 [inline] __mutex_lock+0x12f/0x12f0 kernel/locking/mutex.c:733 blk_request_module+0x25/0x1d0 block/genhd.c:701 blkdev_get_no_open+0x74/0x90 block/bdev.c:737 blkdev_get_by_dev.part.0+0x22/0xc70 block/bdev.c:791 blkdev_get_by_dev+0x6b/0x80 block/bdev.c:847 swsusp_check+0x97/0x420 kernel/power/swap.c:1526 software_resume.part.0+0x102/0x1f0 kernel/power/hibernate.c:979 software_resume kernel/power/hibernate.c:86 [inline] resume_store+0x161/0x190 kernel/power/hibernate.c:1181 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:296 call_write_iter include/linux/fs.h:2074 [inline] new_sync_write+0x431/0x660 fs/read_write.c:503 vfs_write+0x7cd/0xae0 fs/read_write.c:590 ksys_write+0x12d/0x250 fs/read_write.c:643 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0x65/0xf0 arch/x86/entry/common.c:178 do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c -> #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+0x19/0x1f0 kernel/power/hibernate.c:934 software_resume kernel/power/hibernate.c:86 [inline] resume_store+0x161/0x190 kernel/power/hibernate.c:1181 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:296 call_write_iter include/linux/fs.h:2074 [inline] new_sync_write+0x431/0x660 fs/read_write.c:503 vfs_write+0x7cd/0xae0 fs/read_write.c:590 ksys_write+0x12d/0x250 fs/read_write.c:643 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0x65/0xf0 arch/x86/entry/common.c:178 do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c -> #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+0x47/0x470 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:241 call_read_iter include/linux/fs.h:2068 [inline] new_sync_read+0x429/0x6e0 fs/read_write.c:400 vfs_read+0x35c/0x600 fs/read_write.c:481 ksys_read+0x12d/0x250 fs/read_write.c:619 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 proc_reg_read_iter+0x1fb/0x2d0 fs/proc/inode.c:300 call_read_iter include/linux/fs.h:2068 [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:1245 __do_sys_sendfile64 fs/read_write.c:1310 [inline] __se_sys_sendfile64 fs/read_write.c:1296 [inline] __ia32_sys_sendfile64+0x1cc/0x210 fs/read_write.c:1296 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0x65/0xf0 arch/x86/entry/common.c:178 do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c -> #2 (sb_writers#3){.+.+}-{0:0}: percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1722 [inline] sb_start_write include/linux/fs.h:1792 [inline] file_start_write include/linux/fs.h:2937 [inline] lo_write_bvec drivers/block/loop.c:243 [inline] lo_write_simple drivers/block/loop.c:266 [inline] do_req_filebacked drivers/block/loop.c:495 [inline] loop_handle_cmd drivers/block/loop.c:1852 [inline] loop_process_work+0x1499/0x1db0 drivers/block/loop.c:1892 process_one_work+0x9ac/0x1650 kernel/workqueue.c:2307 worker_thread+0x657/0x1110 kernel/workqueue.c:2454 kthread+0x2e9/0x3a0 kernel/kthread.c:377 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 -> #1 ((work_completion)(&worker->work)){+.+.}-{0:0}: process_one_work+0x91b/0x1650 kernel/workqueue.c:2283 worker_thread+0x657/0x1110 kernel/workqueue.c:2454 kthread+0x2e9/0x3a0 kernel/kthread.c:377 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:3063 [inline] check_prevs_add kernel/locking/lockdep.c:3186 [inline] validate_chain kernel/locking/lockdep.c:3801 [inline] __lock_acquire+0x2ad4/0x56c0 kernel/locking/lockdep.c:5027 lock_acquire kernel/locking/lockdep.c:5639 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5604 flush_workqueue+0x110/0x13a0 kernel/workqueue.c:2827 drain_workqueue+0x1a5/0x3c0 kernel/workqueue.c:2992 destroy_workqueue+0x71/0x800 kernel/workqueue.c:4429 __loop_clr_fd+0x1ab/0xe20 drivers/block/loop.c:1124 lo_release+0x1ac/0x1f0 drivers/block/loop.c:1756 blkdev_put_whole block/bdev.c:689 [inline] blkdev_put+0x2de/0x950 block/bdev.c:944 deactivate_locked_super+0x94/0x160 fs/super.c:332 deactivate_super+0xad/0xd0 fs/super.c:363 cleanup_mnt+0x3a2/0x540 fs/namespace.c:1173 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:175 [inline] exit_to_user_mode_prepare+0x27e/0x290 kernel/entry/common.c:207 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300 __do_fast_syscall_32+0x72/0xf0 arch/x86/entry/common.c:181 do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c other info that might help us debug this: Chain exists of: (wq_completion)loop1 --> major_names_lock --> &disk->open_mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&disk->open_mutex); lock(major_names_lock); lock(&disk->open_mutex); lock((wq_completion)loop1); *** DEADLOCK *** 1 lock held by syz-executor.1/3672: #0: ffff8880183a4118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0x99/0x950 block/bdev.c:902 stack backtrace: CPU: 2 PID: 3672 Comm: syz-executor.1 Not tainted 5.17.0-rc6-syzkaller-00226-g07ebd38a0da2 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014 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:2143 check_prev_add kernel/locking/lockdep.c:3063 [inline] check_prevs_add kernel/locking/lockdep.c:3186 [inline] validate_chain kernel/locking/lockdep.c:3801 [inline] __lock_acquire+0x2ad4/0x56c0 kernel/locking/lockdep.c:5027 lock_acquire kernel/locking/lockdep.c:5639 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5604 flush_workqueue+0x110/0x13a0 kernel/workqueue.c:2827 drain_workqueue+0x1a5/0x3c0 kernel/workqueue.c:2992 destroy_workqueue+0x71/0x800 kernel/workqueue.c:4429 __loop_clr_fd+0x1ab/0xe20 drivers/block/loop.c:1124 lo_release+0x1ac/0x1f0 drivers/block/loop.c:1756 blkdev_put_whole block/bdev.c:689 [inline] blkdev_put+0x2de/0x950 block/bdev.c:944 deactivate_locked_super+0x94/0x160 fs/super.c:332 deactivate_super+0xad/0xd0 fs/super.c:363 cleanup_mnt+0x3a2/0x540 fs/namespace.c:1173 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:175 [inline] exit_to_user_mode_prepare+0x27e/0x290 kernel/entry/common.c:207 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300 __do_fast_syscall_32+0x72/0xf0 arch/x86/entry/common.c:181 do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c RIP: 0023:0xf6f19549 Code: 03 74 c0 01 10 05 03 74 b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 RSP: 002b:00000000ffd3572c EFLAGS: 00000296 ORIG_RAX: 0000000000000034 RAX: 0000000000000000 RBX: 00000000ffd357d0 RCX: 000000000000000a RDX: 00000000f7051000 RSI: 0000000000000000 RDI: 00000000f6fca462 RBP: 00000000ffd357d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 ---------------- Code disassembly (best guess): 0: 03 74 c0 01 add 0x1(%rax,%rax,8),%esi 4: 10 05 03 74 b8 01 adc %al,0x1b87403(%rip) # 0x1b8740d a: 10 06 adc %al,(%rsi) c: 03 74 b4 01 add 0x1(%rsp,%rsi,4),%esi 10: 10 07 adc %al,(%rdi) 12: 03 74 b0 01 add 0x1(%rax,%rsi,4),%esi 16: 10 08 adc %cl,(%rax) 18: 03 74 d8 01 add 0x1(%rax,%rbx,8),%esi 1c: 00 00 add %al,(%rax) 1e: 00 00 add %al,(%rax) 20: 00 51 52 add %dl,0x52(%rcx) 23: 55 push %rbp 24: 89 e5 mov %esp,%ebp 26: 0f 34 sysenter 28: cd 80 int $0x80 * 2a: 5d pop %rbp <-- trapping instruction 2b: 5a pop %rdx 2c: 59 pop %rcx 2d: c3 retq 2e: 90 nop 2f: 90 nop 30: 90 nop 31: 90 nop 32: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi 39: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi