Message-ID: <000000000000fbaee205fd026244@google.com>
Date:   Wed, 31 May 2023 12:32:55 -0700
From:   syzbot <syzbot+e94d98936a0ed08bde43@...kaller.appspotmail.com>
To:     almaz.alexandrovich@...agon-software.com,
        linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org,
        llvm@...ts.linux.dev, nathan@...nel.org, ndesaulniers@...gle.com,
        ntfs3@...ts.linux.dev, syzkaller-bugs@...glegroups.com,
        trix@...hat.com
Subject: [syzbot] [ntfs3?] possible deadlock in mark_as_free_ex

Hello,

syzbot found the following issue on:

HEAD commit:    48b1320a674e Merge tag 'for-6.4-rc4-tag' of git://git.kern..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=10ccb25d280000
kernel config:  https://syzkaller.appspot.com/x/.config?x=162cf2103e4a7453
dashboard link: https://syzkaller.appspot.com/bug?extid=e94d98936a0ed08bde43
compiler:       Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/1bdd53056bc4/disk-48b1320a.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/82950e95464f/vmlinux-48b1320a.xz
kernel image: https://storage.googleapis.com/syzbot-assets/8a58eb21a7a7/bzImage-48b1320a.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+e94d98936a0ed08bde43@...kaller.appspotmail.com

======================================================
WARNING: possible circular locking dependency detected
6.4.0-rc4-syzkaller-00051-g48b1320a674e #0 Not tainted
------------------------------------------------------
kworker/u4:0/15666 is trying to acquire lock:
ffff88802d146268 (&wnd->rw_lock){++++}-{3:3}, at: mark_as_free_ex+0x3d/0x330 fs/ntfs3/fsntfs.c:2464

but task is already holding lock:
ffff88804bad60e0 (&ni->ni_lock){+.+.}-{3:3}, at: ni_trylock fs/ntfs3/ntfs_fs.h:1141 [inline]
ffff88804bad60e0 (&ni->ni_lock){+.+.}-{3:3}, at: ni_write_inode+0x167/0x10c0 fs/ntfs3/frecord.c:3252

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&ni->ni_lock){+.+.}-{3:3}:
       lock_acquire+0x1e3/0x520 kernel/locking/lockdep.c:5705
       __mutex_lock_common+0x1d8/0x2530 kernel/locking/mutex.c:603
       __mutex_lock kernel/locking/mutex.c:747 [inline]
       mutex_lock_nested+0x1b/0x20 kernel/locking/mutex.c:799
       ntfs_set_state+0x212/0x730 fs/ntfs3/fsntfs.c:945
       mark_as_free_ex+0x6e/0x330 fs/ntfs3/fsntfs.c:2466
       run_deallocate_ex+0x244/0x5f0 fs/ntfs3/attrib.c:122
       attr_set_size+0x1684/0x4290 fs/ntfs3/attrib.c:750
       ntfs_truncate fs/ntfs3/file.c:393 [inline]
       ntfs3_setattr+0x556/0xb00 fs/ntfs3/file.c:682
       notify_change+0xc8b/0xf40 fs/attr.c:483
       do_truncate+0x220/0x300 fs/open.c:66
       handle_truncate fs/namei.c:3295 [inline]
       do_open fs/namei.c:3640 [inline]
       path_openat+0x294e/0x3170 fs/namei.c:3791
       do_filp_open+0x234/0x490 fs/namei.c:3818
       do_sys_openat2+0x13f/0x500 fs/open.c:1356
       do_sys_open fs/open.c:1372 [inline]
       __do_sys_creat fs/open.c:1448 [inline]
       __se_sys_creat fs/open.c:1442 [inline]
       __x64_sys_creat+0x123/0x160 fs/open.c:1442
       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 (&wnd->rw_lock){++++}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3113 [inline]
       check_prevs_add kernel/locking/lockdep.c:3232 [inline]
       validate_chain+0x166b/0x58f0 kernel/locking/lockdep.c:3847
       __lock_acquire+0x1316/0x2070 kernel/locking/lockdep.c:5088
       lock_acquire+0x1e3/0x520 kernel/locking/lockdep.c:5705
       down_write_nested+0x3d/0x50 kernel/locking/rwsem.c:1689
       mark_as_free_ex+0x3d/0x330 fs/ntfs3/fsntfs.c:2464
       run_deallocate+0x13b/0x230 fs/ntfs3/fsntfs.c:2534
       ni_try_remove_attr_list+0x1558/0x1930 fs/ntfs3/frecord.c:773
       ni_write_inode+0xd14/0x10c0 fs/ntfs3/frecord.c:3318
       write_inode fs/fs-writeback.c:1456 [inline]
       __writeback_single_inode+0x69b/0xfa0 fs/fs-writeback.c:1668
       writeback_sb_inodes+0x8e3/0x11d0 fs/fs-writeback.c:1894
       wb_writeback+0x458/0xc70 fs/fs-writeback.c:2068
       wb_do_writeback fs/fs-writeback.c:2211 [inline]
       wb_workfn+0x400/0xff0 fs/fs-writeback.c:2251
       process_one_work+0x8a0/0x10e0 kernel/workqueue.c:2405
       worker_thread+0xa63/0x1210 kernel/workqueue.c:2552
       kthread+0x2b8/0x350 kernel/kthread.c:379
       ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&ni->ni_lock);
                               lock(&wnd->rw_lock);
                               lock(&ni->ni_lock);
  lock(&wnd->rw_lock);

 *** DEADLOCK ***

3 locks held by kworker/u4:0/15666:
 #0: ffff888019e63938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x77e/0x10e0 kernel/workqueue.c:2378
 #1: ffffc9000ae5fd20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7c8/0x10e0 kernel/workqueue.c:2380
 #2: ffff88804bad60e0 (&ni->ni_lock){+.+.}-{3:3}, at: ni_trylock fs/ntfs3/ntfs_fs.h:1141 [inline]
 #2: ffff88804bad60e0 (&ni->ni_lock){+.+.}-{3:3}, at: ni_write_inode+0x167/0x10c0 fs/ntfs3/frecord.c:3252

stack backtrace:
CPU: 1 PID: 15666 Comm: kworker/u4:0 Not tainted 6.4.0-rc4-syzkaller-00051-g48b1320a674e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023
Workqueue: writeback wb_workfn (flush-7:2)
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:3113 [inline]
 check_prevs_add kernel/locking/lockdep.c:3232 [inline]
 validate_chain+0x166b/0x58f0 kernel/locking/lockdep.c:3847
 __lock_acquire+0x1316/0x2070 kernel/locking/lockdep.c:5088
 lock_acquire+0x1e3/0x520 kernel/locking/lockdep.c:5705
 down_write_nested+0x3d/0x50 kernel/locking/rwsem.c:1689
 mark_as_free_ex+0x3d/0x330 fs/ntfs3/fsntfs.c:2464
 run_deallocate+0x13b/0x230 fs/ntfs3/fsntfs.c:2534
 ni_try_remove_attr_list+0x1558/0x1930 fs/ntfs3/frecord.c:773
 ni_write_inode+0xd14/0x10c0 fs/ntfs3/frecord.c:3318
 write_inode fs/fs-writeback.c:1456 [inline]
 __writeback_single_inode+0x69b/0xfa0 fs/fs-writeback.c:1668
 writeback_sb_inodes+0x8e3/0x11d0 fs/fs-writeback.c:1894
 wb_writeback+0x458/0xc70 fs/fs-writeback.c:2068
 wb_do_writeback fs/fs-writeback.c:2211 [inline]
 wb_workfn+0x400/0xff0 fs/fs-writeback.c:2251
 process_one_work+0x8a0/0x10e0 kernel/workqueue.c:2405
 worker_thread+0xa63/0x1210 kernel/workqueue.c:2552
 kthread+0x2b8/0x350 kernel/kthread.c:379
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>
BTRFS info (device loop3): qgroup scan completed (inconsistency flag cleared)


---
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