syzbot


possible deadlock in f2fs_release_file

Status: upstream: reported on 2023/05/01 17:06
Labels: f2fs (incorrect?)
Reported-by: syzbot+e5b81eaab292e00e7d98@syzkaller.appspotmail.com
First crash: 31d, last: 30d
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [f2fs?] possible deadlock in f2fs_release_file 0 (1) 2023/05/01 17:06

Sample crash report:
syz-executor.0: attempt to access beyond end of device
loop0: rw=2049, sector=77824, nr_sectors = 2048 limit=63271
syz-executor.0: attempt to access beyond end of device
loop0: rw=2049, sector=79872, nr_sectors = 2048 limit=63271
======================================================
WARNING: possible circular locking dependency detected
6.3.0-syzkaller-12049-g58390c8ce1bd #0 Not tainted
------------------------------------------------------
syz-executor.0/7526 is trying to acquire lock:
ffff8880366c9bd8 (&sb->s_type->i_mutex_key#29){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:775 [inline]
ffff8880366c9bd8 (&sb->s_type->i_mutex_key#29){+.+.}-{3:3}, at: f2fs_release_file+0x9b/0x100 fs/f2fs/file.c:1866

but task is already holding lock:
ffff888037e0c448 (&sbi->node_write){++++}-{3:3}, at: f2fs_down_read fs/f2fs/f2fs.h:2087 [inline]
ffff888037e0c448 (&sbi->node_write){++++}-{3:3}, at: f2fs_write_single_data_page+0xa10/0x1d50 fs/f2fs/data.c:2842

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (&sbi->node_write){++++}-{3:3}:
       reacquire_held_locks+0x3aa/0x660 kernel/locking/lockdep.c:5216
       __lock_release kernel/locking/lockdep.c:5405 [inline]
       lock_release+0x36f/0x9d0 kernel/locking/lockdep.c:5711
       up_write+0x79/0x580 kernel/locking/rwsem.c:1625
       f2fs_write_checkpoint+0x13a4/0x1f90 fs/f2fs/checkpoint.c:1651
       __write_checkpoint_sync fs/f2fs/checkpoint.c:1768 [inline]
       __checkpoint_and_complete_reqs+0xda/0x3b0 fs/f2fs/checkpoint.c:1787
       issue_checkpoint_thread+0xda/0x260 fs/f2fs/checkpoint.c:1818
       kthread+0x2b8/0x350 kernel/kthread.c:379
       ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308

-> #1 (&sbi->cp_rwsem){++++}-{3:3}:
       lock_acquire+0x1e3/0x520 kernel/locking/lockdep.c:5691
       down_read+0x3d/0x50 kernel/locking/rwsem.c:1520
       f2fs_down_read fs/f2fs/f2fs.h:2087 [inline]
       f2fs_lock_op fs/f2fs/f2fs.h:2130 [inline]
       f2fs_convert_inline_inode+0x578/0x800 fs/f2fs/inline.c:218
       f2fs_setattr+0xb0c/0x1270 fs/f2fs/file.c:995
       notify_change+0xc8b/0xf40 fs/attr.c:483
       do_truncate+0x220/0x300 fs/open.c:66
       do_sys_ftruncate+0x2e4/0x380 fs/open.c:194
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x63/0xcd

-> #0 (&sb->s_type->i_mutex_key#29){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3108 [inline]
       check_prevs_add kernel/locking/lockdep.c:3227 [inline]
       validate_chain+0x166b/0x58e0 kernel/locking/lockdep.c:3842
       __lock_acquire+0x1295/0x2000 kernel/locking/lockdep.c:5074
       lock_acquire+0x1e3/0x520 kernel/locking/lockdep.c:5691
       down_write+0x3a/0x50 kernel/locking/rwsem.c:1573
       inode_lock include/linux/fs.h:775 [inline]
       f2fs_release_file+0x9b/0x100 fs/f2fs/file.c:1866
       __fput+0x3b7/0x890 fs/file_table.c:321
       task_work_run+0x24a/0x300 kernel/task_work.c:179
       get_signal+0x1606/0x17e0 kernel/signal.c:2650
       arch_do_signal_or_restart+0x91/0x670 arch/x86/kernel/signal.c:306
       exit_to_user_mode_loop+0x6a/0x100 kernel/entry/common.c:168
       exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:204
       __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline]
       syscall_exit_to_user_mode+0x64/0x280 kernel/entry/common.c:297
       do_syscall_64+0x4d/0xc0 arch/x86/entry/common.c:86
       entry_SYSCALL_64_after_hwframe+0x63/0xcd

other info that might help us debug this:

Chain exists of:
  &sb->s_type->i_mutex_key#29 --> &sbi->cp_rwsem --> &sbi->node_write

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  rlock(&sbi->node_write);
                               lock(&sbi->cp_rwsem);
                               lock(&sbi->node_write);
  lock(&sb->s_type->i_mutex_key#29);

 *** DEADLOCK ***

1 lock held by syz-executor.0/7526:
 #0: ffff888037e0c448 (&sbi->node_write){++++}-{3:3}, at: f2fs_down_read fs/f2fs/f2fs.h:2087 [inline]
 #0: ffff888037e0c448 (&sbi->node_write){++++}-{3:3}, at: f2fs_write_single_data_page+0xa10/0x1d50 fs/f2fs/data.c:2842

stack backtrace:
CPU: 1 PID: 7526 Comm: syz-executor.0 Not tainted 6.3.0-syzkaller-12049-g58390c8ce1bd #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106
 check_noncircular+0x2fe/0x3b0 kernel/locking/lockdep.c:2188
 check_prev_add kernel/locking/lockdep.c:3108 [inline]
 check_prevs_add kernel/locking/lockdep.c:3227 [inline]
 validate_chain+0x166b/0x58e0 kernel/locking/lockdep.c:3842
 __lock_acquire+0x1295/0x2000 kernel/locking/lockdep.c:5074
 lock_acquire+0x1e3/0x520 kernel/locking/lockdep.c:5691
 down_write+0x3a/0x50 kernel/locking/rwsem.c:1573
 inode_lock include/linux/fs.h:775 [inline]
 f2fs_release_file+0x9b/0x100 fs/f2fs/file.c:1866
 __fput+0x3b7/0x890 fs/file_table.c:321
 task_work_run+0x24a/0x300 kernel/task_work.c:179
 get_signal+0x1606/0x17e0 kernel/signal.c:2650
 arch_do_signal_or_restart+0x91/0x670 arch/x86/kernel/signal.c:306
 exit_to_user_mode_loop+0x6a/0x100 kernel/entry/common.c:168
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:204
 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline]
 syscall_exit_to_user_mode+0x64/0x280 kernel/entry/common.c:297
 do_syscall_64+0x4d/0xc0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f9fbc28c169
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 90 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f9fbd007168 EFLAGS: 00000246 ORIG_RAX: 0000000000000148
RAX: fffffffffffffffb RBX: 00007f9fbc3abf80 RCX: 00007f9fbc28c169
RDX: 0000000000000001 RSI: 0000000020000240 RDI: 0000000000000005
RBP: 00007f9fbc2e7ca1 R08: 0000000000000000 R09: 0000000000000003
R10: 0000000000001400 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffc6d012c3f R14: 00007f9fbd007300 R15: 0000000000022000
 </TASK>

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets Manager Title
2023/05/01 10:06 upstream 58390c8ce1bd 62df2017 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in f2fs_release_file
2023/04/30 23:16 upstream 58390c8ce1bd 62df2017 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in f2fs_release_file
* Struck through repros no longer work on HEAD.