syzbot

======================================================
WARNING: possible circular locking dependency detected
6.12.0-rc7-syzkaller-00187-gf868cd251776 #0 Not tainted
------------------------------------------------------
syz-executor133/5844 is trying to acquire lock:
ffff88807d9e4258 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_lock_killable+0x1d/0x70 include/linux/mmap_lock.h:153

but task is already holding lock:
ffff8880794a0398 (&sb->s_type->i_mutex_key#14){+.+.}-{3:3}, at: inode_trylock include/linux/fs.h:835 [inline]
ffff8880794a0398 (&sb->s_type->i_mutex_key#14){+.+.}-{3:3}, at: ntfs_file_write_iter+0x291/0x7a0 fs/ntfs3/file.c:1232

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&sb->s_type->i_mutex_key#14){+.+.}-{3:3}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825
       down_write+0x99/0x220 kernel/locking/rwsem.c:1577
       inode_lock include/linux/fs.h:815 [inline]
       ntfs_file_mmap+0x5bc/0x850 fs/ntfs3/file.c:377
       call_mmap include/linux/fs.h:2172 [inline]
       mmap_file mm/internal.h:123 [inline]
       __mmap_region mm/mmap.c:1453 [inline]
       mmap_region+0x1a2a/0x23f0 mm/mmap.c:1603
       do_mmap+0x8f0/0x1000 mm/mmap.c:496
       vm_mmap_pgoff+0x1dd/0x3d0 mm/util.c:588
       ksys_mmap_pgoff+0x4eb/0x720 mm/mmap.c:542
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (&mm->mmap_lock){++++}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3161 [inline]
       check_prevs_add kernel/locking/lockdep.c:3280 [inline]
       validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904
       __lock_acquire+0x1384/0x2050 kernel/locking/lockdep.c:5202
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825
       down_read_killable+0xca/0xd30 kernel/locking/rwsem.c:1547
       mmap_read_lock_killable+0x1d/0x70 include/linux/mmap_lock.h:153
       get_mmap_lock_carefully mm/memory.c:6123 [inline]
       lock_mm_and_find_vma+0x29c/0x2f0 mm/memory.c:6174
       do_user_addr_fault arch/x86/mm/fault.c:1361 [inline]
       handle_page_fault arch/x86/mm/fault.c:1481 [inline]
       exc_page_fault+0x1bf/0x8c0 arch/x86/mm/fault.c:1539
       asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
       fault_in_readable+0x111/0x2d0
       fault_in_iov_iter_readable+0x229/0x280 lib/iov_iter.c:94
       generic_perform_write+0x259/0x6d0 mm/filemap.c:4044
       ntfs_file_write_iter+0x69c/0x7a0 fs/ntfs3/file.c:1259
       new_sync_write fs/read_write.c:590 [inline]
       vfs_write+0xaeb/0xd30 fs/read_write.c:683
       ksys_write+0x183/0x2b0 fs/read_write.c:736
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&sb->s_type->i_mutex_key#14);
                               lock(&mm->mmap_lock);
                               lock(&sb->s_type->i_mutex_key#14);
  rlock(&mm->mmap_lock);

 *** DEADLOCK ***

3 locks held by syz-executor133/5844:
 #0: ffff888030e487f8 (&f->f_pos_lock){+.+.}-{3:3}, at: fdget_pos+0x24e/0x320 fs/file.c:1160
 #1: ffff88807d5b4420 (sb_writers#9){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2931 [inline]
 #1: ffff88807d5b4420 (sb_writers#9){.+.+}-{0:0}, at: vfs_write+0x225/0xd30 fs/read_write.c:679
 #2: ffff8880794a0398 (&sb->s_type->i_mutex_key#14){+.+.}-{3:3}, at: inode_trylock include/linux/fs.h:835 [inline]
 #2: ffff8880794a0398 (&sb->s_type->i_mutex_key#14){+.+.}-{3:3}, at: ntfs_file_write_iter+0x291/0x7a0 fs/ntfs3/file.c:1232

stack backtrace:
CPU: 1 UID: 0 PID: 5844 Comm: syz-executor133 Not tainted 6.12.0-rc7-syzkaller-00187-gf868cd251776 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2074
 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2206
 check_prev_add kernel/locking/lockdep.c:3161 [inline]
 check_prevs_add kernel/locking/lockdep.c:3280 [inline]
 validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904
 __lock_acquire+0x1384/0x2050 kernel/locking/lockdep.c:5202
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825
 down_read_killable+0xca/0xd30 kernel/locking/rwsem.c:1547
 mmap_read_lock_killable+0x1d/0x70 include/linux/mmap_lock.h:153
 get_mmap_lock_carefully mm/memory.c:6123 [inline]
 lock_mm_and_find_vma+0x29c/0x2f0 mm/memory.c:6174
 do_user_addr_fault arch/x86/mm/fault.c:1361 [inline]
 handle_page_fault arch/x86/mm/fault.c:1481 [inline]
 exc_page_fault+0x1bf/0x8c0 arch/x86/mm/fault.c:1539
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0010:fault_in_readable+0x111/0x2d0 mm/gup.c:2228
Code: 8b 6c 24 18 4c 89 ee 48 81 e6 ff 0f 00 00 31 ff e8 94 81 b6 ff 4c 89 e8 48 25 ff 0f 00 00 74 34 49 bf 00 00 00 00 00 fc ff df <41> 8a 5d 00 e8 96 7c b6 ff 43 0f b6 04 3e 84 c0 0f 85 61 01 00 00
RSP: 0018:ffffc90003d67a00 EFLAGS: 00050202
RAX: 00000000000008c2 RBX: 0000000020001946 RCX: ffff88802a450000
RDX: 0000000000000000 RSI: 00000000000008c2 RDI: 0000000000000000
RBP: ffffc90003d67ab8 R08: ffffffff81de6cfc R09: ffffffff84b29389
R10: 0000000000000002 R11: ffff88802a450000 R12: 0000000000000084
R13: 00000000200018c2 R14: 1ffff920007acf48 R15: dffffc0000000000
 fault_in_iov_iter_readable+0x229/0x280 lib/iov_iter.c:94
 generic_perform_write+0x259/0x6d0 mm/filemap.c:4044
 ntfs_file_write_iter+0x69c/0x7a0 fs/ntfs3/file.c:1259
 new_sync_write fs/read_write.c:590 [inline]
 vfs_write+0xaeb/0xd30 fs/read_write.c:683
 ksys_write+0x183/0x2b0 fs/read_write.c:736
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7efd54cd8dc9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 b1 18 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007efd54c8f218 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000000000000002c RCX: 00007efd54cd8dc9
RDX: 0000000000001006 RSI: 0000000020000940 RDI: 0000000000000005
RBP: 00007efd54d816c8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007efd54d816c0
R13: 00007efd54d4d83c R14: 00746e6572727563 R15: 7275632e73646970
 </TASK>
----------------
Code disassembly (best guess):
   0:	8b 6c 24 18          	mov    0x18(%rsp),%ebp
   4:	4c 89 ee             	mov    %r13,%rsi
   7:	48 81 e6 ff 0f 00 00 	and    $0xfff,%rsi
   e:	31 ff                	xor    %edi,%edi
  10:	e8 94 81 b6 ff       	call   0xffb681a9
  15:	4c 89 e8             	mov    %r13,%rax
  18:	48 25 ff 0f 00 00    	and    $0xfff,%rax
  1e:	74 34                	je     0x54
  20:	49 bf 00 00 00 00 00 	movabs $0xdffffc0000000000,%r15
  27:	fc ff df
* 2a:	41 8a 5d 00          	mov    0x0(%r13),%bl <-- trapping instruction
  2e:	e8 96 7c b6 ff       	call   0xffb67cc9
  33:	43 0f b6 04 3e       	movzbl (%r14,%r15,1),%eax
  38:	84 c0                	test   %al,%al
  3a:	0f 85 61 01 00 00    	jne    0x1a1