syzbot

F2FS-fs (loop0): invalid crc value
F2FS-fs (loop0): Found nat_bits in checkpoint
F2FS-fs (loop0): Try to recover 1th superblock, ret: 0
F2FS-fs (loop0): Mounted with checkpoint version = 753bd00b
======================================================
WARNING: possible circular locking dependency detected
5.15.127-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor428/3487 is trying to acquire lock:
ffff8880240c0938 ((wq_completion)loop0){+.+.}-{0:0}, at: flush_workqueue+0x154/0x1610 kernel/workqueue.c:2830

but task is already holding lock:
ffff8881473f8468 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0xa9/0xbe0 drivers/block/loop.c:1365

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #7 (&lo->lo_mutex){+.+.}-{3:3}:
       lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5622
       __mutex_lock_common+0x1da/0x25a0 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+0x68/0x100 drivers/block/loop.c:2055
       blkdev_get_whole+0x94/0x390 block/bdev.c:669
       blkdev_get_by_dev+0x2b2/0xa50 block/bdev.c:824
       blkdev_open+0x138/0x2d0 block/fops.c:463
       do_dentry_open+0x807/0xfb0 fs/open.c:826
       do_open fs/namei.c:3538 [inline]
       path_openat+0x2702/0x2f20 fs/namei.c:3672
       do_filp_open+0x21c/0x460 fs/namei.c:3699
       do_sys_openat2+0x13b/0x500 fs/open.c:1211
       do_sys_open fs/open.c:1227 [inline]
       __do_sys_openat fs/open.c:1243 [inline]
       __se_sys_openat fs/open.c:1238 [inline]
       __x64_sys_openat+0x243/0x290 fs/open.c:1238
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x61/0xcb

-> #6 (&disk->open_mutex){+.+.}-{3:3}:
       lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5622
       __mutex_lock_common+0x1da/0x25a0 kernel/locking/mutex.c:596
       __mutex_lock kernel/locking/mutex.c:729 [inline]
       mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
       blkdev_get_by_dev+0x14d/0xa50 block/bdev.c:817
       swsusp_check+0xb1/0x2c0 kernel/power/swap.c:1526
       software_resume+0xc6/0x3c0 kernel/power/hibernate.c:977
       resume_store+0xe3/0x130 kernel/power/hibernate.c:1179
       kernfs_fop_write_iter+0x3a2/0x4f0 fs/kernfs/file.c:296
       call_write_iter include/linux/fs.h:2103 [inline]
       new_sync_write fs/read_write.c:507 [inline]
       vfs_write+0xacf/0xe50 fs/read_write.c:594
       ksys_write+0x1a2/0x2c0 fs/read_write.c:647
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x61/0xcb

-> #5 (system_transition_mutex/1){+.+.}-{3:3}:
       lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5622
       __mutex_lock_common+0x1da/0x25a0 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/0x3c0 kernel/power/hibernate.c:932
       resume_store+0xe3/0x130 kernel/power/hibernate.c:1179
       kernfs_fop_write_iter+0x3a2/0x4f0 fs/kernfs/file.c:296
       call_write_iter include/linux/fs.h:2103 [inline]
       new_sync_write fs/read_write.c:507 [inline]
       vfs_write+0xacf/0xe50 fs/read_write.c:594
       ksys_write+0x1a2/0x2c0 fs/read_write.c:647
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x61/0xcb

-> #4 (&of->mutex){+.+.}-{3:3}:
       lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5622
       __mutex_lock_common+0x1da/0x25a0 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+0x50/0x3b0 fs/kernfs/file.c:112
       seq_read_iter+0x3d0/0xd10 fs/seq_file.c:225
       call_read_iter include/linux/fs.h:2097 [inline]
       new_sync_read fs/read_write.c:404 [inline]
       vfs_read+0xa9f/0xe10 fs/read_write.c:485
       ksys_read+0x1a2/0x2c0 fs/read_write.c:623
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x61/0xcb

-> #3 (&p->lock){+.+.}-{3:3}:
       lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5622
       __mutex_lock_common+0x1da/0x25a0 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+0xae/0xd10 fs/seq_file.c:182
       proc_reg_read_iter+0x1b7/0x280 fs/proc/inode.c:300
       call_read_iter include/linux/fs.h:2097 [inline]
       generic_file_splice_read+0x4ad/0x790 fs/splice.c:311
       do_splice_to fs/splice.c:796 [inline]
       splice_direct_to_actor+0x448/0xc10 fs/splice.c:870
       do_splice_direct+0x285/0x3d0 fs/splice.c:979
       do_sendfile+0x625/0xff0 fs/read_write.c:1249
       __do_sys_sendfile64 fs/read_write.c:1317 [inline]
       __se_sys_sendfile64+0x178/0x1e0 fs/read_write.c:1303
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x61/0xcb

-> #2 (sb_writers#3){.+.+}-{0:0}:
       lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5622
       percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
       __sb_start_write include/linux/fs.h:1742 [inline]
       sb_start_write include/linux/fs.h:1812 [inline]
       file_start_write include/linux/fs.h:2966 [inline]
       lo_write_bvec+0x1a3/0x740 drivers/block/loop.c:315
       lo_write_simple drivers/block/loop.c:338 [inline]
       do_req_filebacked drivers/block/loop.c:656 [inline]
       loop_handle_cmd drivers/block/loop.c:2234 [inline]
       loop_process_work+0x2309/0x2af0 drivers/block/loop.c:2274
       process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310
       worker_thread+0xaca/0x1280 kernel/workqueue.c:2457
       kthread+0x3f6/0x4f0 kernel/kthread.c:319
       ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298

-> #1 ((work_completion)(&lo->rootcg_work)){+.+.}-{0:0}:
       lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5622
       process_one_work+0x7f1/0x10c0 kernel/workqueue.c:2286
       worker_thread+0xaca/0x1280 kernel/workqueue.c:2457
       kthread+0x3f6/0x4f0 kernel/kthread.c:319
       ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298

-> #0 ((wq_completion)loop0){+.+.}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3053 [inline]
       check_prevs_add kernel/locking/lockdep.c:3172 [inline]
       validate_chain+0x1646/0x58b0 kernel/locking/lockdep.c:3787
       __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5011
       lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5622
       flush_workqueue+0x170/0x1610 kernel/workqueue.c:2830
       drain_workqueue+0xc5/0x390 kernel/workqueue.c:2995
       destroy_workqueue+0x7b/0xae0 kernel/workqueue.c:4430
       __loop_clr_fd+0x241/0xbe0 drivers/block/loop.c:1383
       blkdev_put_whole block/bdev.c:692 [inline]
       blkdev_put+0x455/0x790 block/bdev.c:954
       kill_f2fs_super+0x2ff/0x3c0 fs/f2fs/super.c:4501
       deactivate_locked_super+0xa0/0x110 fs/super.c:335
       cleanup_mnt+0x44e/0x500 fs/namespace.c:1143
       task_work_run+0x129/0x1a0 kernel/task_work.c:164
       exit_task_work include/linux/task_work.h:32 [inline]
       do_exit+0x6a3/0x2480 kernel/exit.c:872
       do_group_exit+0x144/0x310 kernel/exit.c:994
       __do_sys_exit_group kernel/exit.c:1005 [inline]
       __se_sys_exit_group kernel/exit.c:1003 [inline]
       __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1003
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x61/0xcb

other info that might help us debug this:

Chain exists of:
  (wq_completion)loop0 --> &disk->open_mutex --> &lo->lo_mutex

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&lo->lo_mutex);
                               lock(&disk->open_mutex);
                               lock(&lo->lo_mutex);
  lock((wq_completion)loop0);

 *** DEADLOCK ***

2 locks held by syz-executor428/3487:
 #0: ffff88801b604118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0xfb/0x790 block/bdev.c:912
 #1: ffff8881473f8468 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0xa9/0xbe0 drivers/block/loop.c:1365

stack backtrace:
CPU: 0 PID: 3487 Comm: syz-executor428 Not tainted 5.15.127-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 check_noncircular+0x2f8/0x3b0 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+0x1646/0x58b0 kernel/locking/lockdep.c:3787
 __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5011
 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5622
 flush_workqueue+0x170/0x1610 kernel/workqueue.c:2830
 drain_workqueue+0xc5/0x390 kernel/workqueue.c:2995
 destroy_workqueue+0x7b/0xae0 kernel/workqueue.c:4430
 __loop_clr_fd+0x241/0xbe0 drivers/block/loop.c:1383
 blkdev_put_whole block/bdev.c:692 [inline]
 blkdev_put+0x455/0x790 block/bdev.c:954
 kill_f2fs_super+0x2ff/0x3c0 fs/f2fs/super.c:4501
 deactivate_locked_super+0xa0/0x110 fs/super.c:335
 cleanup_mnt+0x44e/0x500 fs/namespace.c:1143
 task_work_run+0x129/0x1a0 kernel/task_work.c:164
 exit_task_work include/linux/task_work.h:32 [inline]
 do_exit+0x6a3/0x2480 kernel/exit.c:872
 do_group_exit+0x144/0x310 kernel/exit.c:994
 __do_sys_exit_group kernel/exit.c:1005 [inline]
 __se_sys_exit_group kernel/exit.c:1003 [inline]
 __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1003
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f15bf4b5b49
Code: Unable to access opcode bytes at RIP 0x7f15bf4b5b1f.
RSP: 002b:00007ffe6d1339b8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f15bf4b5b49
RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000001
RBP: 00007f15bf5393d0 R08: ffffffffffffffb8 R09: 0000555555e4e378
R10: 0000000000000003 R11: 0000000000000246 R12: 00007f15bf5393d0
R13: 0000000000000000 R14: 00007f15bf53a140 R15: 00007f15bf483e20
 </TASK>