syzbot

EXT4-fs (loop0): 1 truncate cleaned up
EXT4-fs (loop0): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: writeback.
======================================================
WARNING: possible circular locking dependency detected
6.14.0-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor670/5329 is trying to acquire lock:
ffff88804567a1b0 (&sb->s_type->i_mutex_key#8/1){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:877 [inline]
ffff88804567a1b0 (&sb->s_type->i_mutex_key#8/1){+.+.}-{4:4}, at: ext4_xattr_inode_create fs/ext4/xattr.c:1514 [inline]
ffff88804567a1b0 (&sb->s_type->i_mutex_key#8/1){+.+.}-{4:4}, at: ext4_xattr_inode_lookup_create+0x17de/0x1c70 fs/ext4/xattr.c:1596

but task is already holding lock:
ffff8880456551c8 (&ei->i_data_sem/3){++++}-{4:4}, at: ext4_setattr+0x16e1/0x1da0 fs/ext4/inode.c:5505

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&ei->i_data_sem/3){++++}-{4:4}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
       down_write+0x99/0x220 kernel/locking/rwsem.c:1577
       ext4_update_i_disksize fs/ext4/ext4.h:3375 [inline]
       ext4_xattr_inode_write fs/ext4/xattr.c:1452 [inline]
       ext4_xattr_inode_lookup_create+0x1484/0x1c70 fs/ext4/xattr.c:1602
       ext4_xattr_ibody_set+0x214/0x730 fs/ext4/xattr.c:2269
       ext4_xattr_set_handle+0xba6/0x1580 fs/ext4/xattr.c:2446
       ext4_xattr_set+0x280/0x3e0 fs/ext4/xattr.c:2560
       __vfs_setxattr+0x468/0x4a0 fs/xattr.c:200
       __vfs_setxattr_noperm+0x12e/0x660 fs/xattr.c:234
       vfs_setxattr+0x221/0x430 fs/xattr.c:321
       do_setxattr fs/xattr.c:636 [inline]
       filename_setxattr+0x2af/0x430 fs/xattr.c:665
       path_setxattrat+0x440/0x510 fs/xattr.c:713
       __do_sys_lsetxattr fs/xattr.c:754 [inline]
       __se_sys_lsetxattr fs/xattr.c:750 [inline]
       __x64_sys_lsetxattr+0xbf/0xe0 fs/xattr.c:750
       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 (&sb->s_type->i_mutex_key#8/1){+.+.}-{4:4}:
       check_prev_add kernel/locking/lockdep.c:3163 [inline]
       check_prevs_add kernel/locking/lockdep.c:3282 [inline]
       validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3906
       __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5228
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
       down_write+0x99/0x220 kernel/locking/rwsem.c:1577
       inode_lock include/linux/fs.h:877 [inline]
       ext4_xattr_inode_create fs/ext4/xattr.c:1514 [inline]
       ext4_xattr_inode_lookup_create+0x17de/0x1c70 fs/ext4/xattr.c:1596
       ext4_xattr_block_set+0x26c/0x32d0 fs/ext4/xattr.c:1916
       ext4_xattr_move_to_block fs/ext4/xattr.c:2670 [inline]
       ext4_xattr_make_inode_space fs/ext4/xattr.c:2745 [inline]
       ext4_expand_extra_isize_ea+0x1182/0x1cf0 fs/ext4/xattr.c:2837
       __ext4_expand_extra_isize+0x306/0x400 fs/ext4/inode.c:5889
       ext4_try_to_expand_extra_isize fs/ext4/inode.c:5932 [inline]
       __ext4_mark_inode_dirty+0x524/0x880 fs/ext4/inode.c:6010
       ext4_setattr+0x1780/0x1da0 fs/ext4/inode.c:5508
       notify_change+0xbca/0xe90 fs/attr.c:552
       do_truncate+0x220/0x310 fs/open.c:65
       handle_truncate fs/namei.c:3451 [inline]
       do_open fs/namei.c:3834 [inline]
       path_openat+0x2e1b/0x3590 fs/namei.c:3989
       do_filp_open+0x27f/0x4e0 fs/namei.c:4016
       do_sys_openat2+0x13e/0x1d0 fs/open.c:1428
       do_sys_open fs/open.c:1443 [inline]
       __do_sys_creat fs/open.c:1521 [inline]
       __se_sys_creat fs/open.c:1515 [inline]
       __x64_sys_creat+0x123/0x170 fs/open.c:1515
       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(&ei->i_data_sem/3);
                               lock(&sb->s_type->i_mutex_key#8/1);
                               lock(&ei->i_data_sem/3);
  lock(&sb->s_type->i_mutex_key#8/1);

 *** DEADLOCK ***

5 locks held by syz-executor670/5329:
 #0: ffff8880425c8420 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:547
 #1: ffff888045655338 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: inode_lock include/linux/fs.h:877 [inline]
 #1: ffff888045655338 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: do_truncate+0x20c/0x310 fs/open.c:63
 #2: ffff8880456554d8 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock include/linux/fs.h:922 [inline]
 #2: ffff8880456554d8 (mapping.invalidate_lock){++++}-{4:4}, at: ext4_setattr+0xf94/0x1da0 fs/ext4/inode.c:5453
 #3: ffff8880456551c8 (&ei->i_data_sem/3){++++}-{4:4}, at: ext4_setattr+0x16e1/0x1da0 fs/ext4/inode.c:5505
 #4: ffff888045655008 (&ei->xattr_sem){++++}-{4:4}, at: ext4_write_trylock_xattr fs/ext4/xattr.h:161 [inline]
 #4: ffff888045655008 (&ei->xattr_sem){++++}-{4:4}, at: ext4_try_to_expand_extra_isize fs/ext4/inode.c:5929 [inline]
 #4: ffff888045655008 (&ei->xattr_sem){++++}-{4:4}, at: __ext4_mark_inode_dirty+0x491/0x880 fs/ext4/inode.c:6010

stack backtrace:
CPU: 0 UID: 0 PID: 5329 Comm: syz-executor670 Not tainted 6.14.0-syzkaller #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
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:2076
 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2208
 check_prev_add kernel/locking/lockdep.c:3163 [inline]
 check_prevs_add kernel/locking/lockdep.c:3282 [inline]
 validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3906
 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5228
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
 down_write+0x99/0x220 kernel/locking/rwsem.c:1577
 inode_lock include/linux/fs.h:877 [inline]
 ext4_xattr_inode_create fs/ext4/xattr.c:1514 [inline]
 ext4_xattr_inode_lookup_create+0x17de/0x1c70 fs/ext4/xattr.c:1596
 ext4_xattr_block_set+0x26c/0x32d0 fs/ext4/xattr.c:1916
 ext4_xattr_move_to_block fs/ext4/xattr.c:2670 [inline]
 ext4_xattr_make_inode_space fs/ext4/xattr.c:2745 [inline]
 ext4_expand_extra_isize_ea+0x1182/0x1cf0 fs/ext4/xattr.c:2837
 __ext4_expand_extra_isize+0x306/0x400 fs/ext4/inode.c:5889
 ext4_try_to_expand_extra_isize fs/ext4/inode.c:5932 [inline]
 __ext4_mark_inode_dirty+0x524/0x880 fs/ext4/inode.c:6010
 ext4_setattr+0x1780/0x1da0 fs/ext4/inode.c:5508
 notify_change+0xbca/0xe90 fs/attr.c:552
 do_truncate+0x220/0x310 fs/open.c:65
 handle_truncate fs/namei.c:3451 [inline]
 do_open fs/namei.c:3834 [inline]
 path_openat+0x2e1b/0x3590 fs/namei.c:3989
 do_filp_open+0x27f/0x4e0 fs/namei.c:4016
 do_sys_openat2+0x13e/0x1d0 fs/open.c:1428
 do_sys_open fs/open.c:1443 [inline]
 __do_sys_creat fs/open.c:1521 [inline]
 __se_sys_creat fs/open.c:1515 [inline]
 __x64_sys_creat+0x123/0x170 fs/open.c:1515
 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: 0033:0x7fb7da2182e9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 21 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd09100f88 EFLAGS: 00000246 ORIG_RAX: 0000000000000055
RAX: ffffffffffffffda RBX: 0031656c69662f2e RCX: 00007fb7da2182e9
RDX: 00007fb7da2182e9 RSI: 00000000000001ad RDI: 0000200000000300
RBP: 0000000000000000 R08: 00007ffd09100fc0 R09: 00007ffd09100fc0
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd09100fac
R13: 0000000000000008 R14: 431bde82d7b634db R15: 00007ffd09100fe0
 </TASK>