syzbot

======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
kworker/u4:9/4480 is trying to acquire lock:
ffff888056c50940 (&rl->lock){++++}-{3:3}, at: ntfs_read_block fs/ntfs/aops.c:248 [inline]
ffff888056c50940 (&rl->lock){++++}-{3:3}, at: ntfs_read_folio+0x1439/0x2980 fs/ntfs/aops.c:436

but task is already holding lock:
ffff888056c53310 (&ni->mrec_lock){+.+.}-{3:3}, at: map_mft_record+0x4c/0x650 fs/ntfs/mft.c:154

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&ni->mrec_lock){+.+.}-{3:3}:
       __mutex_lock_common kernel/locking/mutex.c:603 [inline]
       __mutex_lock+0x12d/0xae0 kernel/locking/mutex.c:747
       map_mft_record+0x4c/0x650 fs/ntfs/mft.c:154
       ntfs_attr_extend_allocation+0x509/0x4340 fs/ntfs/attrib.c:2002
       ntfs_prepare_file_for_write fs/ntfs/file.c:391 [inline]
       ntfs_file_write_iter+0x3c0/0x1bf0 fs/ntfs/file.c:1915
       call_write_iter include/linux/fs.h:2265 [inline]
       new_sync_write fs/read_write.c:491 [inline]
       vfs_write+0x482/0x9a0 fs/read_write.c:584
       ksys_write+0x14d/0x260 fs/read_write.c:637
       do_syscall_x64 arch/x86/entry/common.c:46 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #0 (&rl->lock){++++}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3090 [inline]
       check_prevs_add kernel/locking/lockdep.c:3209 [inline]
       validate_chain kernel/locking/lockdep.c:3825 [inline]
       __lock_acquire+0x2c92/0x7bd0 kernel/locking/lockdep.c:5049
       lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5662
       down_read+0x42/0x2d0 kernel/locking/rwsem.c:1520
       ntfs_read_block fs/ntfs/aops.c:248 [inline]
       ntfs_read_folio+0x1439/0x2980 fs/ntfs/aops.c:436
       filemap_read_folio+0x164/0x7a0 mm/filemap.c:2490
       do_read_cache_folio+0x29e/0x790 mm/filemap.c:3659
       do_read_cache_page+0x32/0x230 mm/filemap.c:3701
       read_mapping_page include/linux/pagemap.h:793 [inline]
       ntfs_map_page fs/ntfs/aops.h:75 [inline]
       ntfs_sync_mft_mirror+0x24e/0x1a90 fs/ntfs/mft.c:480
       write_mft_record_nolock+0x1207/0x1990 fs/ntfs/mft.c:787
       write_mft_record+0x136/0x310 fs/ntfs/mft.h:95
       __ntfs_write_inode+0x6ae/0xbe0 fs/ntfs/inode.c:3050
       write_inode fs/fs-writeback.c:1470 [inline]
       __writeback_single_inode+0x76c/0x1170 fs/fs-writeback.c:1687
       writeback_sb_inodes+0xad5/0x17f0 fs/fs-writeback.c:1913
       wb_writeback+0x470/0xd40 fs/fs-writeback.c:2087
       wb_do_writeback fs/fs-writeback.c:2230 [inline]
       wb_workfn+0x423/0xee0 fs/fs-writeback.c:2270
       process_one_work+0x8ab/0x1160 kernel/workqueue.c:2292
       worker_thread+0xaf5/0x12a0 kernel/workqueue.c:2439
       kthread+0x29d/0x330 kernel/kthread.c:376
       ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&ni->mrec_lock);
                               lock(&rl->lock);
                               lock(&ni->mrec_lock);
  lock(&rl->lock);

 *** DEADLOCK ***

3 locks held by kworker/u4:9/4480:
 #0: ffff888144e50938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
 #1: ffffc900038f7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
 #2: ffff888056c53310 (&ni->mrec_lock){+.+.}-{3:3}, at: map_mft_record+0x4c/0x650 fs/ntfs/mft.c:154

stack backtrace:
CPU: 0 PID: 4480 Comm: kworker/u4:9 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Workqueue: writeback wb_workfn (flush-7:3)
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106
 check_noncircular+0x296/0x330 kernel/locking/lockdep.c:2170
 check_prev_add kernel/locking/lockdep.c:3090 [inline]
 check_prevs_add kernel/locking/lockdep.c:3209 [inline]
 validate_chain kernel/locking/lockdep.c:3825 [inline]
 __lock_acquire+0x2c92/0x7bd0 kernel/locking/lockdep.c:5049
 lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5662
 down_read+0x42/0x2d0 kernel/locking/rwsem.c:1520
 ntfs_read_block fs/ntfs/aops.c:248 [inline]
 ntfs_read_folio+0x1439/0x2980 fs/ntfs/aops.c:436
 filemap_read_folio+0x164/0x7a0 mm/filemap.c:2490
 do_read_cache_folio+0x29e/0x790 mm/filemap.c:3659
 do_read_cache_page+0x32/0x230 mm/filemap.c:3701
 read_mapping_page include/linux/pagemap.h:793 [inline]
 ntfs_map_page fs/ntfs/aops.h:75 [inline]
 ntfs_sync_mft_mirror+0x24e/0x1a90 fs/ntfs/mft.c:480
 write_mft_record_nolock+0x1207/0x1990 fs/ntfs/mft.c:787
 write_mft_record+0x136/0x310 fs/ntfs/mft.h:95
 __ntfs_write_inode+0x6ae/0xbe0 fs/ntfs/inode.c:3050
 write_inode fs/fs-writeback.c:1470 [inline]
 __writeback_single_inode+0x76c/0x1170 fs/fs-writeback.c:1687
 writeback_sb_inodes+0xad5/0x17f0 fs/fs-writeback.c:1913
 wb_writeback+0x470/0xd40 fs/fs-writeback.c:2087
 wb_do_writeback fs/fs-writeback.c:2230 [inline]
 wb_workfn+0x423/0xee0 fs/fs-writeback.c:2270
 process_one_work+0x8ab/0x1160 kernel/workqueue.c:2292
 worker_thread+0xaf5/0x12a0 kernel/workqueue.c:2439
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
wlan0: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
wlan0: Creating new IBSS network, BSSID 50:50:50:50:50:50
IPv6: ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready
wlan1: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
wlan1: Creating new IBSS network, BSSID 50:50:50:50:50:50
IPv6: ADDRCONF(NETDEV_CHANGE): wlan1: link becomes ready