syzbot

======================================================
WARNING: possible circular locking dependency detected
6.12.0-syzkaller-11677-g2ba9f676d0a2 #0 Not tainted
------------------------------------------------------
syz-executor331/5818 is trying to acquire lock:
ffff88807b8fbae0 (&mm->mmap_lock){++++}-{4:4}, at: gup_fast_fallback+0x230/0x2b80 mm/gup.c:3407

but task is already holding lock:
ffff888071d18398 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:818 [inline]
ffff888071d18398 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: __blockdev_direct_IO+0x31d/0x4890 fs/direct-io.c:1140

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
       down_write+0x99/0x220 kernel/locking/rwsem.c:1577
       inode_lock include/linux/fs.h:818 [inline]
       ntfs_file_mmap+0x5bc/0x850 fs/ntfs3/file.c:379
       call_mmap include/linux/fs.h:2183 [inline]
       mmap_file mm/internal.h:124 [inline]
       __mmap_new_file_vma mm/vma.c:2291 [inline]
       __mmap_new_vma mm/vma.c:2355 [inline]
       __mmap_region+0x2204/0x2cd0 mm/vma.c:2456
       mmap_region+0x226/0x2c0 mm/mmap.c:1347
       do_mmap+0x8f0/0x1000 mm/mmap.c:496
       vm_mmap_pgoff+0x1dd/0x3d0 mm/util.c:580
       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){++++}-{4:4}:
       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+0x1397/0x2100 kernel/locking/lockdep.c:5226
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
       gup_fast_fallback+0x249/0x2b80 mm/gup.c:3407
       pin_user_pages_fast+0xcc/0x160 mm/gup.c:3531
       iov_iter_extract_user_pages lib/iov_iter.c:1844 [inline]
       iov_iter_extract_pages+0x3bb/0x5c0 lib/iov_iter.c:1907
       dio_refill_pages fs/direct-io.c:172 [inline]
       dio_get_page fs/direct-io.c:213 [inline]
       do_direct_IO fs/direct-io.c:915 [inline]
       __blockdev_direct_IO+0x1443/0x4890 fs/direct-io.c:1243
       blockdev_direct_IO include/linux/fs.h:3313 [inline]
       ntfs_direct_IO+0x194/0x370 fs/ntfs3/inode.c:806
       generic_file_read_iter+0x341/0x550 mm/filemap.c:2811
       new_sync_read fs/read_write.c:484 [inline]
       vfs_read+0x991/0xb70 fs/read_write.c:565
       ksys_read+0x18f/0x2b0 fs/read_write.c:708
       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 ***

1 lock held by syz-executor331/5818:
 #0: ffff888071d18398 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:818 [inline]
 #0: ffff888071d18398 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: __blockdev_direct_IO+0x31d/0x4890 fs/direct-io.c:1140

stack backtrace:
CPU: 1 UID: 0 PID: 5818 Comm: syz-executor331 Not tainted 6.12.0-syzkaller-11677-g2ba9f676d0a2 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
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+0x1397/0x2100 kernel/locking/lockdep.c:5226
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
 gup_fast_fallback+0x249/0x2b80 mm/gup.c:3407
 pin_user_pages_fast+0xcc/0x160 mm/gup.c:3531
 iov_iter_extract_user_pages lib/iov_iter.c:1844 [inline]
 iov_iter_extract_pages+0x3bb/0x5c0 lib/iov_iter.c:1907
 dio_refill_pages fs/direct-io.c:172 [inline]
 dio_get_page fs/direct-io.c:213 [inline]
 do_direct_IO fs/direct-io.c:915 [inline]
 __blockdev_direct_IO+0x1443/0x4890 fs/direct-io.c:1243
 blockdev_direct_IO include/linux/fs.h:3313 [inline]
 ntfs_direct_IO+0x194/0x370 fs/ntfs3/inode.c:806
 generic_file_read_iter+0x341/0x550 mm/filemap.c:2811
 new_sync_read fs/read_write.c:484 [inline]
 vfs_read+0x991/0xb70 fs/read_write.c:565
 ksys_read+0x18f/0x2b0 fs/read_write.c:708
 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: 0033:0x7f77d867ed59
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 17 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fffb251d198 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 0031656c69662f2e RCX: 00007f77d867ed59
RDX: 0000000000002000 RSI: 0000000020000000 RDI: 0000000000000006
RBP: 0000000000000000 R08: 00005555861fd4c0 R09: 00005555861fd4c0
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fffb251d1c0
R13: 00007fffb251d3e8 R14: 431bde82d7b634db R15: 00007f77d86c803b
 </TASK>