syzbot

EXT4-fs (loop0): encrypted files will use data=ordered instead of data journaling mode
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
6.15.0-rc2-syzkaller-00278-gfc96b232f8e7 #0 Not tainted
------------------------------------------------------
syz-executor347/5335 is trying to acquire lock:
ffff8880452f0e20 (&sb->s_type->i_mutex_key#8/1){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline]
ffff8880452f0e20 (&sb->s_type->i_mutex_key#8/1){+.+.}-{4:4}, at: ext4_xattr_inode_create fs/ext4/xattr.c:1506 [inline]
ffff8880452f0e20 (&sb->s_type->i_mutex_key#8/1){+.+.}-{4:4}, at: ext4_xattr_inode_lookup_create+0x1846/0x1cd0 fs/ext4/xattr.c:1588

but task is already holding lock:
ffff8880452f3e38 (&ei->i_data_sem/3){++++}-{4:4}, at: ext4_setattr+0x15f1/0x1c60 fs/ext4/inode.c:5564

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+0x116/0x2f0 kernel/locking/lockdep.c:5866
       down_write+0x9c/0x220 kernel/locking/rwsem.c:1577
       ext4_update_i_disksize fs/ext4/ext4.h:3402 [inline]
       ext4_xattr_inode_write fs/ext4/xattr.c:1444 [inline]
       ext4_xattr_inode_lookup_create+0x14df/0x1cd0 fs/ext4/xattr.c:1594
       ext4_xattr_ibody_set+0x214/0x730 fs/ext4/xattr.c:2258
       ext4_xattr_set_handle+0x103a/0x1a20 fs/ext4/xattr.c:2435
       ext4_xattr_set+0x284/0x400 fs/ext4/xattr.c:2549
       __vfs_setxattr+0x468/0x4a0 fs/xattr.c:200
       __vfs_setxattr_noperm+0x12e/0x660 fs/xattr.c:234
       vfs_setxattr+0x223/0x430 fs/xattr.c:321
       do_setxattr fs/xattr.c:636 [inline]
       filename_setxattr+0x2dd/0x480 fs/xattr.c:665
       path_setxattrat+0x3f7/0x4c0 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/syscall_64.c:63 [inline]
       do_syscall_64+0xf3/0x210 arch/x86/entry/syscall_64.c:94
       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:3166 [inline]
       check_prevs_add kernel/locking/lockdep.c:3285 [inline]
       validate_chain+0xa69/0x24e0 kernel/locking/lockdep.c:3909
       __lock_acquire+0xad5/0xd80 kernel/locking/lockdep.c:5235
       lock_acquire+0x116/0x2f0 kernel/locking/lockdep.c:5866
       down_write+0x9c/0x220 kernel/locking/rwsem.c:1577
       inode_lock include/linux/fs.h:867 [inline]
       ext4_xattr_inode_create fs/ext4/xattr.c:1506 [inline]
       ext4_xattr_inode_lookup_create+0x1846/0x1cd0 fs/ext4/xattr.c:1588
       ext4_xattr_block_set+0x26e/0x32c0 fs/ext4/xattr.c:1908
       ext4_xattr_move_to_block fs/ext4/xattr.c:2659 [inline]
       ext4_xattr_make_inode_space fs/ext4/xattr.c:2734 [inline]
       ext4_expand_extra_isize_ea+0x1452/0x2100 fs/ext4/xattr.c:2822
       __ext4_expand_extra_isize+0x309/0x410 fs/ext4/inode.c:5950
       ext4_try_to_expand_extra_isize fs/ext4/inode.c:5993 [inline]
       __ext4_mark_inode_dirty+0x526/0x880 fs/ext4/inode.c:6071
       ext4_setattr+0x1672/0x1c60 fs/ext4/inode.c:5567
       notify_change+0xbca/0xe90 fs/attr.c:552
       do_truncate+0x222/0x310 fs/open.c:65
       handle_truncate fs/namei.c:3466 [inline]
       do_open fs/namei.c:3849 [inline]
       path_openat+0x2e4f/0x35d0 fs/namei.c:4004
       do_filp_open+0x284/0x4e0 fs/namei.c:4031
       do_sys_openat2+0x12b/0x1d0 fs/open.c:1429
       do_sys_open fs/open.c:1444 [inline]
       __do_sys_openat fs/open.c:1460 [inline]
       __se_sys_openat fs/open.c:1455 [inline]
       __x64_sys_openat+0x249/0x2a0 fs/open.c:1455
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0xf3/0x210 arch/x86/entry/syscall_64.c:94
       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-executor347/5335:
 #0: ffff8880442b4420 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:556
 #1: ffff8880452f3fa8 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline]
 #1: ffff8880452f3fa8 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: do_truncate+0x20e/0x310 fs/open.c:63
 #2: ffff8880452f4148 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock include/linux/fs.h:912 [inline]
 #2: ffff8880452f4148 (mapping.invalidate_lock){++++}-{4:4}, at: ext4_setattr+0xf59/0x1c60 fs/ext4/inode.c:5512
 #3: ffff8880452f3e38 (&ei->i_data_sem/3){++++}-{4:4}, at: ext4_setattr+0x15f1/0x1c60 fs/ext4/inode.c:5564
 #4: ffff8880452f3c38 (&ei->xattr_sem){++++}-{4:4}, at: ext4_write_trylock_xattr fs/ext4/xattr.h:164 [inline]
 #4: ffff8880452f3c38 (&ei->xattr_sem){++++}-{4:4}, at: ext4_try_to_expand_extra_isize fs/ext4/inode.c:5990 [inline]
 #4: ffff8880452f3c38 (&ei->xattr_sem){++++}-{4:4}, at: __ext4_mark_inode_dirty+0x493/0x880 fs/ext4/inode.c:6071

stack backtrace:
CPU: 0 UID: 0 PID: 5335 Comm: syz-executor347 Not tainted 6.15.0-rc2-syzkaller-00278-gfc96b232f8e7 #0 PREEMPT(full) 
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+0x2e1/0x300 kernel/locking/lockdep.c:2079
 check_noncircular+0x142/0x160 kernel/locking/lockdep.c:2211
 check_prev_add kernel/locking/lockdep.c:3166 [inline]
 check_prevs_add kernel/locking/lockdep.c:3285 [inline]
 validate_chain+0xa69/0x24e0 kernel/locking/lockdep.c:3909
 __lock_acquire+0xad5/0xd80 kernel/locking/lockdep.c:5235
 lock_acquire+0x116/0x2f0 kernel/locking/lockdep.c:5866
 down_write+0x9c/0x220 kernel/locking/rwsem.c:1577
 inode_lock include/linux/fs.h:867 [inline]
 ext4_xattr_inode_create fs/ext4/xattr.c:1506 [inline]
 ext4_xattr_inode_lookup_create+0x1846/0x1cd0 fs/ext4/xattr.c:1588
 ext4_xattr_block_set+0x26e/0x32c0 fs/ext4/xattr.c:1908
 ext4_xattr_move_to_block fs/ext4/xattr.c:2659 [inline]
 ext4_xattr_make_inode_space fs/ext4/xattr.c:2734 [inline]
 ext4_expand_extra_isize_ea+0x1452/0x2100 fs/ext4/xattr.c:2822
 __ext4_expand_extra_isize+0x309/0x410 fs/ext4/inode.c:5950
 ext4_try_to_expand_extra_isize fs/ext4/inode.c:5993 [inline]
 __ext4_mark_inode_dirty+0x526/0x880 fs/ext4/inode.c:6071
 ext4_setattr+0x1672/0x1c60 fs/ext4/inode.c:5567
 notify_change+0xbca/0xe90 fs/attr.c:552
 do_truncate+0x222/0x310 fs/open.c:65
 handle_truncate fs/namei.c:3466 [inline]
 do_open fs/namei.c:3849 [inline]
 path_openat+0x2e4f/0x35d0 fs/namei.c:4004
 do_filp_open+0x284/0x4e0 fs/namei.c:4031
 do_sys_openat2+0x12b/0x1d0 fs/open.c:1429
 do_sys_open fs/open.c:1444 [inline]
 __do_sys_openat fs/open.c:1460 [inline]
 __se_sys_openat fs/open.c:1455 [inline]
 __x64_sys_openat+0x249/0x2a0 fs/open.c:1455
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf3/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f388690e2e9
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:00007fffaeeef808 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00002000000000c0 RCX: 00007f388690e2e9
RDX: 0000000000802240 RSI: 00002000000000c0 RDI: 00000000ffffff9c
RBP: 0031656c69662f2e R08: 00007fffaeeef840 R09: 00007fffaeeef840
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fffaeeef82c
R13: 000000000000000b R14: 431bde82d7b634db R15: 00007fffaeeef860
 </TASK>