====================================================== WARNING: possible circular locking dependency detected 5.15.189-syzkaller #0 Not tainted ------------------------------------------------------ syz.5.1035/9030 is trying to acquire lock: ffffffff8c6f9ec8 (major_names_lock){+.+.}-{3:3}, at: blk_probe_dev block/genhd.c:682 [inline] ffffffff8c6f9ec8 (major_names_lock){+.+.}-{3:3}, at: blk_request_module+0x31/0x290 block/genhd.c:698 but task is already holding lock: ffffffff8bfd50a8 (system_transition_mutex/1){+.+.}-{3:3}, at: software_resume+0x7c/0x3b0 kernel/power/hibernate.c:937 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #8 (system_transition_mutex/1){+.+.}-{3:3}: __mutex_lock_common+0x1eb/0x2390 kernel/locking/mutex.c:596 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 software_resume+0x7c/0x3b0 kernel/power/hibernate.c:937 resume_store+0xe4/0x130 kernel/power/hibernate.c:1184 kernfs_fop_write_iter+0x379/0x4c0 fs/kernfs/file.c:296 call_write_iter include/linux/fs.h:2172 [inline] new_sync_write fs/read_write.c:507 [inline] vfs_write+0x712/0xd00 fs/read_write.c:594 ksys_write+0x14d/0x250 fs/read_write.c:647 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 -> #7 (&of->mutex){+.+.}-{3:3}: __mutex_lock_common+0x1eb/0x2390 kernel/locking/mutex.c:596 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 kernfs_seq_start+0x51/0x3c0 fs/kernfs/file.c:112 seq_read_iter+0x3c4/0xd50 fs/seq_file.c:225 call_read_iter include/linux/fs.h:2166 [inline] new_sync_read fs/read_write.c:404 [inline] vfs_read+0x725/0xcf0 fs/read_write.c:485 ksys_read+0x14d/0x250 fs/read_write.c:623 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 -> #6 (&p->lock){+.+.}-{3:3}: __mutex_lock_common+0x1eb/0x2390 kernel/locking/mutex.c:596 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 seq_read_iter+0xad/0xd50 fs/seq_file.c:182 do_iter_readv_writev+0x497/0x600 fs/read_write.c:-1 do_iter_read+0x20b/0x7c0 fs/read_write.c:790 lo_read_simple drivers/block/loop.c:392 [inline] do_req_filebacked drivers/block/loop.c:663 [inline] loop_handle_cmd drivers/block/loop.c:2235 [inline] loop_process_work+0x18dc/0x2480 drivers/block/loop.c:2275 process_one_work+0x863/0x1000 kernel/workqueue.c:2310 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 -> #5 ((work_completion)(&lo->rootcg_work)){+.+.}-{0:0}: process_one_work+0x7bf/0x1000 kernel/workqueue.c:2286 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 -> #4 ((wq_completion)loop6){+.+.}-{0:0}: flush_workqueue+0x142/0x1380 kernel/workqueue.c:2830 drain_workqueue+0xcf/0x380 kernel/workqueue.c:2995 destroy_workqueue+0x7b/0xb20 kernel/workqueue.c:4439 __loop_clr_fd+0x234/0xb90 drivers/block/loop.c:1384 blkdev_put_whole block/bdev.c:692 [inline] blkdev_put+0x53f/0x7d0 block/bdev.c:957 cramfs_kill_sb+0xd7/0x110 fs/cramfs/inode.c:503 deactivate_locked_super+0x93/0xf0 fs/super.c:335 cleanup_mnt+0x418/0x4d0 fs/namespace.c:1139 task_work_run+0x125/0x1a0 kernel/task_work.c:188 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop+0x10f/0x130 kernel/entry/common.c:181 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 -> #3 (&lo->lo_mutex){+.+.}-{3:3}: __mutex_lock_common+0x1eb/0x2390 kernel/locking/mutex.c:596 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_killable_nested+0x17/0x20 kernel/locking/mutex.c:758 lo_open+0x6a/0x100 drivers/block/loop.c:2056 blkdev_get_whole+0x90/0x390 block/bdev.c:669 blkdev_get_by_dev+0x2d0/0xa60 block/bdev.c:827 blkdev_open+0x12d/0x2c0 block/fops.c:466 do_dentry_open+0x7ff/0xf80 fs/open.c:826 do_open fs/namei.c:3608 [inline] path_openat+0x2682/0x2f30 fs/namei.c:3742 do_filp_open+0x1b3/0x3e0 fs/namei.c:3769 do_sys_openat2+0x142/0x4a0 fs/open.c:1253 do_sys_open fs/open.c:1269 [inline] __do_sys_openat fs/open.c:1285 [inline] __se_sys_openat fs/open.c:1280 [inline] __x64_sys_openat+0x135/0x160 fs/open.c:1280 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 -> #2 (&disk->open_mutex){+.+.}-{3:3}: __mutex_lock_common+0x1eb/0x2390 kernel/locking/mutex.c:596 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 bd_register_pending_holders+0x33/0x310 block/holder.c:161 device_add_disk+0x5a7/0xd40 block/genhd.c:486 add_disk include/linux/genhd.h:200 [inline] md_alloc+0x809/0xc00 drivers/md/md.c:5782 blk_probe_dev block/genhd.c:685 [inline] blk_request_module+0x26e/0x290 block/genhd.c:-1 blkdev_get_no_open+0x38/0x1d0 block/bdev.c:740 blkdev_get_by_dev+0x77/0xa60 block/bdev.c:807 blkdev_open+0x12d/0x2c0 block/fops.c:466 do_dentry_open+0x7ff/0xf80 fs/open.c:826 do_open fs/namei.c:3608 [inline] path_openat+0x2682/0x2f30 fs/namei.c:3742 do_filp_open+0x1b3/0x3e0 fs/namei.c:3769 do_sys_openat2+0x142/0x4a0 fs/open.c:1253 do_sys_open fs/open.c:1269 [inline] __do_sys_openat fs/open.c:1285 [inline] __se_sys_openat fs/open.c:1280 [inline] __x64_sys_openat+0x135/0x160 fs/open.c:1280 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 -> #1 (disks_mutex){+.+.}-{3:3}: __mutex_lock_common+0x1eb/0x2390 kernel/locking/mutex.c:596 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 md_alloc+0x48/0xc00 drivers/md/md.c:5723 blk_probe_dev block/genhd.c:685 [inline] blk_request_module+0x26e/0x290 block/genhd.c:-1 blkdev_get_no_open+0x38/0x1d0 block/bdev.c:740 blkdev_get_by_dev+0x77/0xa60 block/bdev.c:807 blkdev_open+0x12d/0x2c0 block/fops.c:466 do_dentry_open+0x7ff/0xf80 fs/open.c:826 do_open fs/namei.c:3608 [inline] path_openat+0x2682/0x2f30 fs/namei.c:3742 do_filp_open+0x1b3/0x3e0 fs/namei.c:3769 do_sys_openat2+0x142/0x4a0 fs/open.c:1253 do_sys_open fs/open.c:1269 [inline] __do_sys_openat fs/open.c:1285 [inline] __se_sys_openat fs/open.c:1280 [inline] __x64_sys_openat+0x135/0x160 fs/open.c:1280 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 -> #0 (major_names_lock){+.+.}-{3:3}: check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain kernel/locking/lockdep.c:3788 [inline] __lock_acquire+0x2c33/0x7c60 kernel/locking/lockdep.c:5012 lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623 __mutex_lock_common+0x1eb/0x2390 kernel/locking/mutex.c:596 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 blk_probe_dev block/genhd.c:682 [inline] blk_request_module+0x31/0x290 block/genhd.c:698 blkdev_get_no_open+0x38/0x1d0 block/bdev.c:740 blkdev_get_by_dev+0x77/0xa60 block/bdev.c:807 swsusp_check+0x9b/0x2a0 kernel/power/swap.c:1526 software_resume+0xc6/0x3b0 kernel/power/hibernate.c:982 resume_store+0xe4/0x130 kernel/power/hibernate.c:1184 kernfs_fop_write_iter+0x379/0x4c0 fs/kernfs/file.c:296 call_write_iter include/linux/fs.h:2172 [inline] new_sync_write fs/read_write.c:507 [inline] vfs_write+0x712/0xd00 fs/read_write.c:594 ksys_write+0x14d/0x250 fs/read_write.c:647 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 other info that might help us debug this: Chain exists of: major_names_lock --> &of->mutex --> system_transition_mutex/1 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(system_transition_mutex/1); lock(&of->mutex); lock(system_transition_mutex/1); lock(major_names_lock); *** DEADLOCK *** 5 locks held by syz.5.1035/9030: #0: ffff8880600b8ff0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2bf/0x370 fs/file.c:1058 #1: ffff88807e97e460 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x28a/0xd00 fs/read_write.c:590 #2: ffff8880250fc888 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e5/0x4c0 fs/kernfs/file.c:287 #3: ffff888144bfd830 (kn->active#671){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x208/0x4c0 fs/kernfs/file.c:288 #4: ffffffff8bfd50a8 (system_transition_mutex/1){+.+.}-{3:3}, at: software_resume+0x7c/0x3b0 kernel/power/hibernate.c:937 stack backtrace: CPU: 0 PID: 9030 Comm: syz.5.1035 Not tainted 5.15.189-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106 check_noncircular+0x274/0x310 kernel/locking/lockdep.c:2133 check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain kernel/locking/lockdep.c:3788 [inline] __lock_acquire+0x2c33/0x7c60 kernel/locking/lockdep.c:5012 lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623 __mutex_lock_common+0x1eb/0x2390 kernel/locking/mutex.c:596 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 blk_probe_dev block/genhd.c:682 [inline] blk_request_module+0x31/0x290 block/genhd.c:698 blkdev_get_no_open+0x38/0x1d0 block/bdev.c:740 blkdev_get_by_dev+0x77/0xa60 block/bdev.c:807 swsusp_check+0x9b/0x2a0 kernel/power/swap.c:1526 software_resume+0xc6/0x3b0 kernel/power/hibernate.c:982 resume_store+0xe4/0x130 kernel/power/hibernate.c:1184 kernfs_fop_write_iter+0x379/0x4c0 fs/kernfs/file.c:296 call_write_iter include/linux/fs.h:2172 [inline] new_sync_write fs/read_write.c:507 [inline] vfs_write+0x712/0xd00 fs/read_write.c:594 ksys_write+0x14d/0x250 fs/read_write.c:647 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fcc97d699a9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fcc95b8f038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fcc97f91160 RCX: 00007fcc97d699a9 RDX: 0000000000000012 RSI: 0000200000000040 RDI: 0000000000000006 RBP: 00007fcc97debd69 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fcc97f91160 R15: 00007ffde28fb788 block device autoloading is deprecated and will be removed. PM: Image not found (code -22)