syzbot

loop0: detected capacity change from 0 to 4096
======================================================
WARNING: possible circular locking dependency detected
5.15.179-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor271/4018 is trying to acquire lock:
ffff0000ddbdf240 (&sb->s_type->i_mutex_key#17){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline]
ffff0000ddbdf240 (&sb->s_type->i_mutex_key#17){+.+.}-{3:3}, at: ntfs_file_mmap+0x4b0/0x688 fs/ntfs3/file.c:401

but task is already holding lock:
ffff0000c1f44bd8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline]
ffff0000c1f44bd8 (&mm->mmap_lock){++++}-{3:3}, at: vm_mmap_pgoff+0x15c/0x2b4 mm/util.c:549

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&mm->mmap_lock){++++}-{3:3}:
       __might_fault+0xc8/0x128 mm/memory.c:5357
       fault_in_readable+0xdc/0x56c mm/gup.c:1793
       fault_in_iov_iter_readable+0x130/0x1b0 lib/iov_iter.c:460
       generic_perform_write+0x198/0x520 mm/filemap.c:3775
       __generic_file_write_iter+0x230/0x454 mm/filemap.c:3912
       ntfs_file_write_iter+0x40c/0x49c fs/ntfs3/file.c:1143
       call_write_iter include/linux/fs.h:2172 [inline]
       new_sync_write fs/read_write.c:507 [inline]
       vfs_write+0x884/0xb44 fs/read_write.c:594
       ksys_write+0x15c/0x26c fs/read_write.c:647
       __do_sys_write fs/read_write.c:659 [inline]
       __se_sys_write fs/read_write.c:656 [inline]
       __arm64_sys_write+0x7c/0x90 fs/read_write.c:656
       __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
       invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
       el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
       do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
       el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608
       el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626
       el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584

-> #0 (&sb->s_type->i_mutex_key#17){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3053 [inline]
       check_prevs_add kernel/locking/lockdep.c:3172 [inline]
       validate_chain kernel/locking/lockdep.c:3788 [inline]
       __lock_acquire+0x32d4/0x7638 kernel/locking/lockdep.c:5012
       lock_acquire+0x240/0x77c kernel/locking/lockdep.c:5623
       down_write+0xbc/0x12c kernel/locking/rwsem.c:1551
       inode_lock include/linux/fs.h:787 [inline]
       ntfs_file_mmap+0x4b0/0x688 fs/ntfs3/file.c:401
       call_mmap include/linux/fs.h:2177 [inline]
       mmap_file+0x6c/0xc8 mm/util.c:1092
       __mmap_region mm/mmap.c:1784 [inline]
       mmap_region+0xb24/0x1408 mm/mmap.c:2921
       do_mmap+0x698/0xdc4 mm/mmap.c:1574
       vm_mmap_pgoff+0x1a4/0x2b4 mm/util.c:551
       ksys_mmap_pgoff+0x458/0x668 mm/mmap.c:1623
       __do_sys_mmap arch/arm64/kernel/sys.c:28 [inline]
       __se_sys_mmap arch/arm64/kernel/sys.c:21 [inline]
       __arm64_sys_mmap+0xf8/0x110 arch/arm64/kernel/sys.c:21
       __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
       invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
       el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
       do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
       el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608
       el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626
       el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&mm->mmap_lock);
                               lock(&sb->s_type->i_mutex_key#17);
                               lock(&mm->mmap_lock);
  lock(&sb->s_type->i_mutex_key#17);

 *** DEADLOCK ***

1 lock held by syz-executor271/4018:
 #0: ffff0000c1f44bd8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline]
 #0: ffff0000c1f44bd8 (&mm->mmap_lock){++++}-{3:3}, at: vm_mmap_pgoff+0x15c/0x2b4 mm/util.c:549

stack backtrace:
CPU: 0 PID: 4018 Comm: syz-executor271 Not tainted 5.15.179-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call trace:
 dump_backtrace+0x0/0x530 arch/arm64/kernel/stacktrace.c:152
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:216
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x108/0x170 lib/dump_stack.c:106
 dump_stack+0x1c/0x58 lib/dump_stack.c:113
 print_circular_bug+0x150/0x1b8 kernel/locking/lockdep.c:2011
 check_noncircular+0x2cc/0x378 kernel/locking/lockdep.c:2133
 check_prev_add kernel/locking/lockdep.c:3053 [inline]
 check_prevs_add kernel/locking/lockdep.c:3172 [inline]
 validate_chain kernel/locking/lockdep.c:3788 [inline]
 __lock_acquire+0x32d4/0x7638 kernel/locking/lockdep.c:5012
 lock_acquire+0x240/0x77c kernel/locking/lockdep.c:5623
 down_write+0xbc/0x12c kernel/locking/rwsem.c:1551
 inode_lock include/linux/fs.h:787 [inline]
 ntfs_file_mmap+0x4b0/0x688 fs/ntfs3/file.c:401
 call_mmap include/linux/fs.h:2177 [inline]
 mmap_file+0x6c/0xc8 mm/util.c:1092
 __mmap_region mm/mmap.c:1784 [inline]
 mmap_region+0xb24/0x1408 mm/mmap.c:2921
 do_mmap+0x698/0xdc4 mm/mmap.c:1574
 vm_mmap_pgoff+0x1a4/0x2b4 mm/util.c:551
 ksys_mmap_pgoff+0x458/0x668 mm/mmap.c:1623
 __do_sys_mmap arch/arm64/kernel/sys.c:28 [inline]
 __se_sys_mmap arch/arm64/kernel/sys.c:21 [inline]
 __arm64_sys_mmap+0xf8/0x110 arch/arm64/kernel/sys.c:21
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
 el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608
 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626
 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584
ntfs3: loop0: ino=21, "net_prio.prioidx" failed to extend initialized size to 208e24b.