====================================================== WARNING: possible circular locking dependency detected 5.16.0-syzkaller #0 Not tainted ------------------------------------------------------ udevd/4227 is trying to acquire lock: ffff88807e9dd138 ((wq_completion)loop2){+.+.}-{0:0}, at: flush_workqueue+0xe1/0x13a0 kernel/workqueue.c:2824 but task is already holding lock: ffff88801a4161a8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put_whole+0x4f/0x1b0 block/bdev.c:728 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_whole+0x4f/0x3c0 block/bdev.c:705 blkdev_get_by_dev.part.0+0x35a/0x9a0 block/bdev.c:862 blkdev_get_by_dev+0x6b/0x80 block/bdev.c:878 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+0x342/0x500 fs/kernfs/file.c:296 call_write_iter include/linux/fs.h:2086 [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_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+0x19/0x1f0 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+0x342/0x500 fs/kernfs/file.c:296 call_write_iter include/linux/fs.h:2086 [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_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+0x4b/0x260 fs/kernfs/file.c:112 seq_read_iter+0x2c6/0x1280 fs/seq_file.c:225 kernfs_fop_read_iter+0x44f/0x5f0 fs/kernfs/file.c:241 call_read_iter include/linux/fs.h:2080 [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 call_read_iter include/linux/fs.h:2080 [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] __x64_sys_sendfile64+0x1cc/0x210 fs/read_write.c:1296 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#3){.+.+}-{0:0}: percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1734 [inline] sb_start_write include/linux/fs.h:1804 [inline] file_start_write include/linux/fs.h:2949 [inline] lo_write_bvec drivers/block/loop.c:242 [inline] lo_write_simple drivers/block/loop.c:265 [inline] do_req_filebacked drivers/block/loop.c:494 [inline] loop_handle_cmd drivers/block/loop.c:1812 [inline] loop_process_work+0x1499/0x1db0 drivers/block/loop.c:1852 process_one_work+0x9ac/0x1650 kernel/workqueue.c:2307 worker_thread+0x657/0x1110 kernel/workqueue.c:2454 kthread+0x2e9/0x3a0 kernel/kthread.c:359 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 -> #1 ((work_completion)(&lo->rootcg_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:359 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 -> #0 ((wq_completion)loop2){+.+.}-{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+0x2a2c/0x5470 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+0x1a7/0xd20 drivers/block/loop.c:1116 lo_release+0x1a7/0x1f0 drivers/block/loop.c:1716 blkdev_put_whole+0xf6/0x1b0 block/bdev.c:732 blkdev_put+0x228/0x670 block/bdev.c:946 blkdev_close+0x6a/0x80 block/fops.c:515 __fput+0x286/0x9f0 fs/file_table.c:280 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_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)loop2 --> 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)loop2); *** DEADLOCK *** 1 lock held by udevd/4227: #0: ffff88801a4161a8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put_whole+0x4f/0x1b0 block/bdev.c:728 stack backtrace: CPU: 1 PID: 4227 Comm: udevd Not tainted 5.16.0-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: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+0x2a2c/0x5470 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+0x1a7/0xd20 drivers/block/loop.c:1116 lo_release+0x1a7/0x1f0 drivers/block/loop.c:1716 blkdev_put_whole+0xf6/0x1b0 block/bdev.c:732 blkdev_put+0x228/0x670 block/bdev.c:946 blkdev_close+0x6a/0x80 block/fops.c:515 __fput+0x286/0x9f0 fs/file_table.c:280 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_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f65eae64fc3 Code: 48 ff ff ff b8 ff ff ff ff e9 3e ff ff ff 66 0f 1f 84 00 00 00 00 00 64 8b 04 25 18 00 00 00 85 c0 75 14 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 45 c3 0f 1f 40 00 48 83 ec 18 89 7c 24 0c e8 RSP: 002b:00007ffe5f57a1f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 00007f65ead0d6a8 RCX: 00007f65eae64fc3 RDX: 000000000000001c RSI: 00007ffe5f5799f8 RDI: 0000000000000008 RBP: 000055b7e2a660c0 R08: 0000000000000007 R09: 000055b7e2a61a60 R10: 000000000176fad2 R11: 0000000000000246 R12: 0000000000000002 R13: 000055b7e2a5a640 R14: 0000000000000008 R15: 000055b7e2a40910 I/O error, dev loop3, sector 1 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0 Buffer I/O error on dev loop3, logical block 1, async page read I/O error, dev loop3, sector 2 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0 Buffer I/O error on dev loop3, logical block 2, async page read I/O error, dev loop3, sector 1 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0 Buffer I/O error on dev loop3, logical block 1, async page read Buffer I/O error on dev loop3, logical block 2, async page read Buffer I/O error on dev loop1, logical block 1, async page read Buffer I/O error on dev loop1, logical block 2, async page read I/O error, dev loop0, sector 1 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0 I/O error, dev loop0, sector 2 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0 I/O error, dev loop0, sector 3 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0 I/O error, dev loop0, sector 4 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0 buffer_io_error: 14 callbacks suppressed Buffer I/O error on dev loop3, logical block 1, async page read Buffer I/O error on dev loop3, logical block 2, async page read Buffer I/O error on dev loop3, logical block 3, async page read Buffer I/O error on dev loop3, logical block 4, async page read Buffer I/O error on dev loop3, logical block 5, async page read Buffer I/O error on dev loop3, logical block 6, async page read Buffer I/O error on dev loop3, logical block 7, async page read Buffer I/O error on dev loop3, logical block 1, async page read I/O error, dev loop5, sector 0 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 0 I/O error, dev loop5, sector 1 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0 Buffer I/O error on dev loop5, logical block 1, async page read