Re: [syzbot] [f2fs?] possible deadlock in f2fs_release_file

From: syzbot
Date: Thu Jun 15 2023 - 04:39:29 EST

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syzbot has found a reproducer for the following issue on:

HEAD commit: b6dad5178cea Merge tag 'nios2_fix_v6.4' of git://git.kerne..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=12510203280000
kernel config: https://syzkaller.appspot.com/x/.config?x=5bcee04c3b2a8237
dashboard link: https://syzkaller.appspot.com/bug?extid=e5b81eaab292e00e7d98
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10db66f7280000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=14577753280000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/0ae77e66553b/disk-b6dad517.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/5b2da4d23e74/vmlinux-b6dad517.xz
kernel image: https://storage.googleapis.com/syzbot-assets/23130b8e7a8a/bzImage-b6dad517.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/70b8358ae62a/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+e5b81eaab292e00e7d98@xxxxxxxxxxxxxxxxxxxxxxxxx

loop4: rw=2049, sector=77824, nr_sectors = 3048 limit=63271
syz-executor110: attempt to access beyond end of device
loop4: rw=2049, sector=80872, nr_sectors = 1048 limit=63271
======================================================
WARNING: possible circular locking dependency detected
6.4.0-rc6-syzkaller-00037-gb6dad5178cea #0 Not tainted
------------------------------------------------------
syz-executor110/5218 is trying to acquire lock:
ffff88806676b660 (&sb->s_type->i_mutex_key#17){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:775 [inline]
ffff88806676b660 (&sb->s_type->i_mutex_key#17){+.+.}-{3:3}, at: f2fs_release_file fs/f2fs/file.c:1866 [inline]
ffff88806676b660 (&sb->s_type->i_mutex_key#17){+.+.}-{3:3}, at: f2fs_release_file+0xca/0x100 fs/f2fs/file.c:1856

but task is already holding lock:
ffff88802100c448 (&sbi->node_write){++++}-{3:3}, at: f2fs_down_read fs/f2fs/f2fs.h:2087 [inline]
ffff88802100c448 (&sbi->node_write){++++}-{3:3}, at: f2fs_write_single_data_page+0x166e/0x19d0 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}:
__lock_release kernel/locking/lockdep.c:5419 [inline]
lock_release+0x33c/0x670 kernel/locking/lockdep.c:5725
up_write+0x2a/0x520 kernel/locking/rwsem.c:1625
f2fs_up_write fs/f2fs/f2fs.h:2122 [inline]
block_operations+0xca4/0xe80 fs/f2fs/checkpoint.c:1288
f2fs_write_checkpoint+0x5fa/0x4b40 fs/f2fs/checkpoint.c:1651
__write_checkpoint_sync fs/f2fs/checkpoint.c:1768 [inline]
__checkpoint_and_complete_reqs+0xea/0x350 fs/f2fs/checkpoint.c:1787
issue_checkpoint_thread+0xe3/0x250 fs/f2fs/checkpoint.c:1818
kthread+0x344/0x440 kernel/kthread.c:379
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308

-> #1 (&sbi->cp_rwsem){++++}-{3:3}:
down_read+0x9c/0x480 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+0x47b/0x8e0 fs/f2fs/inline.c:218
f2fs_preallocate_blocks fs/f2fs/file.c:4480 [inline]
f2fs_file_write_iter+0x1a1f/0x24d0 fs/f2fs/file.c:4712
call_write_iter include/linux/fs.h:1868 [inline]
do_iter_readv_writev+0x20b/0x3b0 fs/read_write.c:735
do_iter_write+0x185/0x7e0 fs/read_write.c:860
vfs_writev+0x1aa/0x670 fs/read_write.c:933
do_pwritev+0x1b6/0x270 fs/read_write.c:1030
__do_sys_pwritev2 fs/read_write.c:1089 [inline]
__se_sys_pwritev2 fs/read_write.c:1080 [inline]
__x64_sys_pwritev2+0xef/0x150 fs/read_write.c:1080
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

-> #0 (&sb->s_type->i_mutex_key#17){+.+.}-{3:3}:
check_prev_add kernel/locking/lockdep.c:3113 [inline]
check_prevs_add kernel/locking/lockdep.c:3232 [inline]
validate_chain kernel/locking/lockdep.c:3847 [inline]
__lock_acquire+0x2fcd/0x5f30 kernel/locking/lockdep.c:5088
lock_acquire kernel/locking/lockdep.c:5705 [inline]
lock_acquire+0x1b1/0x520 kernel/locking/lockdep.c:5670
down_write+0x92/0x200 kernel/locking/rwsem.c:1573
inode_lock include/linux/fs.h:775 [inline]
f2fs_release_file fs/f2fs/file.c:1866 [inline]
f2fs_release_file+0xca/0x100 fs/f2fs/file.c:1856
__fput+0x27c/0xa90 fs/file_table.c:321
task_work_run+0x16f/0x270 kernel/task_work.c:179
get_signal+0x1c7/0x25b0 kernel/signal.c:2652
arch_do_signal_or_restart+0x79/0x5c0 arch/x86/kernel/signal.c:306
exit_to_user_mode_loop kernel/entry/common.c:168 [inline]
exit_to_user_mode_prepare+0x11f/0x240 kernel/entry/common.c:204
__syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline]
syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:297
do_syscall_64+0x46/0xb0 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#17 --> &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#17);

*** DEADLOCK ***

1 lock held by syz-executor110/5218:
#0: ffff88802100c448 (&sbi->node_write){++++}-{3:3}, at: f2fs_down_read fs/f2fs/f2fs.h:2087 [inline]
#0: ffff88802100c448 (&sbi->node_write){++++}-{3:3}, at: f2fs_write_single_data_page+0x166e/0x19d0 fs/f2fs/data.c:2842

stack backtrace:
CPU: 1 PID: 5218 Comm: syz-executor110 Not tainted 6.4.0-rc6-syzkaller-00037-gb6dad5178cea #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106
check_noncircular+0x25f/0x2e0 kernel/locking/lockdep.c:2188
check_prev_add kernel/locking/lockdep.c:3113 [inline]
check_prevs_add kernel/locking/lockdep.c:3232 [inline]
validate_chain kernel/locking/lockdep.c:3847 [inline]
__lock_acquire+0x2fcd/0x5f30 kernel/locking/lockdep.c:5088
lock_acquire kernel/locking/lockdep.c:5705 [inline]
lock_acquire+0x1b1/0x520 kernel/locking/lockdep.c:5670
down_write+0x92/0x200 kernel/locking/rwsem.c:1573
inode_lock include/linux/fs.h:775 [inline]
f2fs_release_file fs/f2fs/file.c:1866 [inline]
f2fs_release_file+0xca/0x100 fs/f2fs/file.c:1856
__fput+0x27c/0xa90 fs/file_table.c:321
task_work_run+0x16f/0x270 kernel/task_work.c:179
get_signal+0x1c7/0x25b0 kernel/signal.c:2652
arch_do_signal_or_restart+0x79/0x5c0 arch/x86/kernel/signal.c:306
exit_to_user_mode_loop kernel/entry/common.c:168 [inline]
exit_to_user_mode_prepare+0x11f/0x240 kernel/entry/common.c:204
__syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline]
syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:297
do_syscall_64+0x46/0xb0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f6b9a0179b9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 a1 15 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:00007f6b99fc32f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000148
RAX: fffffffffffffffb RBX: 00007f6b9a0a47a8 RCX: 00007f6b9a0179b9
RDX: 0000000000000001 RSI: 0000000020000240 RDI: 0000000000000004
RBP: 00007f6b9a0a47a0 R08: 0000000000000000 R09: 0000000000000003
R10: 0000000000001400 R11: 0000000000000246 R12: 00007f6b9a0a47ac
R13: 00007f6b9a071008 R14: 6f6f6c2f7665642f R15: 0000000000022000
</TASK>

---
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Next message: Oliver Upton: "Re: [PATCH v5 0/7] KVM: arm64: Add support for FEAT_TLBIRANGE"
Previous message: Varadarajan Narayanan: "Re: [PATCH 9/9] arm64: defconfig: Enable QCOM M31 USB phy driver"
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