loop4: detected capacity change from 0 to 4096
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.4.1342/9545 is trying to acquire lock:
ffff888031744270 (&wnd->rw_lock){++++}-{3:3}, at: ntfs_look_for_free_space+0xda/0x650 fs/ntfs3/fsntfs.c:362

but task is already holding lock:
ffff88805cdf77b0 (&ni->file.run_lock#2){++++}-{3:3}, at: ntfs_set_size+0x140/0x200 fs/ntfs3/inode.c:849

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&ni->file.run_lock#2){++++}-{3:3}:
       down_read+0x46/0x2e0 kernel/locking/rwsem.c:1520
       run_unpack_ex+0x7fb/0xb80 fs/ntfs3/run.c:1126
       ntfs_read_mft fs/ntfs3/inode.c:401 [inline]
       ntfs_iget5+0x2475/0x38a0 fs/ntfs3/inode.c:535
       ntfs_dir_emit fs/ntfs3/dir.c:338 [inline]
       ntfs_read_hdr+0x7d4/0xc30 fs/ntfs3/dir.c:386
       ntfs_readdir+0xacb/0xeb0 fs/ntfs3/dir.c:497
       iterate_dir+0x1c2/0x580 fs/readdir.c:106
       __do_sys_getdents fs/readdir.c:322 [inline]
       __se_sys_getdents+0xf6/0x260 fs/readdir.c:307
       do_syscall_x64 arch/x86/entry/common.c:46 [inline]
       do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #0 (&wnd->rw_lock){++++}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3134 [inline]
       check_prevs_add kernel/locking/lockdep.c:3253 [inline]
       validate_chain kernel/locking/lockdep.c:3869 [inline]
       __lock_acquire+0x2df1/0x7d40 kernel/locking/lockdep.c:5137
       lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754
       down_write_nested+0x9e/0x200 kernel/locking/rwsem.c:1689
       ntfs_look_for_free_space+0xda/0x650 fs/ntfs3/fsntfs.c:362
       attr_allocate_clusters+0x1be/0x6b0 fs/ntfs3/attrib.c:159
       attr_set_size+0x1516/0x2d70 fs/ntfs3/attrib.c:577
       ntfs_set_size+0x164/0x200 fs/ntfs3/inode.c:851
       ntfs_extend+0x157/0x4d0 fs/ntfs3/file.c:335
       ntfs_file_write_iter+0x3a7/0x700 fs/ntfs3/file.c:1122
       call_write_iter include/linux/fs.h:2018 [inline]
       new_sync_write fs/read_write.c:491 [inline]
       vfs_write+0x46c/0x990 fs/read_write.c:584
       ksys_write+0x150/0x260 fs/read_write.c:637
       do_syscall_x64 arch/x86/entry/common.c:46 [inline]
       do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&ni->file.run_lock#2);
                               lock(&wnd->rw_lock);
                               lock(&ni->file.run_lock#2);
  lock(&wnd->rw_lock);

 *** DEADLOCK ***

5 locks held by syz.4.1342/9545:
 #0: ffff88802e786848 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2a3/0x330 fs/file.c:1040
 #1: ffff888031742418 (sb_writers#27){.+.+}-{0:0}, at: vfs_write+0x21b/0x990 fs/read_write.c:580
 #2: ffff88805cdf79b0 (&sb->s_type->i_mutex_key#35){+.+.}-{3:3}, at: inode_trylock include/linux/fs.h:824 [inline]
 #2: ffff88805cdf79b0 (&sb->s_type->i_mutex_key#35){+.+.}-{3:3}, at: ntfs_file_write_iter+0x23e/0x700 fs/ntfs3/file.c:1100
 #3: ffff88805cdf7700 (&ni->ni_lock/5){+.+.}-{3:3}, at: ni_lock fs/ntfs3/ntfs_fs.h:1120 [inline]
 #3: ffff88805cdf7700 (&ni->ni_lock/5){+.+.}-{3:3}, at: ntfs_set_size+0x131/0x200 fs/ntfs3/inode.c:848
 #4: ffff88805cdf77b0 (&ni->file.run_lock#2){++++}-{3:3}, at: ntfs_set_size+0x140/0x200 fs/ntfs3/inode.c:849

stack backtrace:
CPU: 1 PID: 9545 Comm: syz.4.1342 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
 check_noncircular+0x2fc/0x400 kernel/locking/lockdep.c:2187
 check_prev_add kernel/locking/lockdep.c:3134 [inline]
 check_prevs_add kernel/locking/lockdep.c:3253 [inline]
 validate_chain kernel/locking/lockdep.c:3869 [inline]
 __lock_acquire+0x2df1/0x7d40 kernel/locking/lockdep.c:5137
 lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754
 down_write_nested+0x9e/0x200 kernel/locking/rwsem.c:1689
 ntfs_look_for_free_space+0xda/0x650 fs/ntfs3/fsntfs.c:362
 attr_allocate_clusters+0x1be/0x6b0 fs/ntfs3/attrib.c:159
 attr_set_size+0x1516/0x2d70 fs/ntfs3/attrib.c:577
 ntfs_set_size+0x164/0x200 fs/ntfs3/inode.c:851
 ntfs_extend+0x157/0x4d0 fs/ntfs3/file.c:335
 ntfs_file_write_iter+0x3a7/0x700 fs/ntfs3/file.c:1122
 call_write_iter include/linux/fs.h:2018 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x46c/0x990 fs/read_write.c:584
 ksys_write+0x150/0x260 fs/read_write.c:637
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f420099cdd9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f42017fb028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f4200c15fa0 RCX: 00007f420099cdd9
RDX: 0000000000000050 RSI: 0000200000000080 RDI: 0000000000000004
RBP: 00007f4200a32d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4200c16038 R14: 00007f4200c15fa0 R15: 00007ffdf9a6a598
 </TASK>