syzbot

loop0: detected capacity change from 0 to 512
EXT4-fs: Ignoring removed i_version option
EXT4-fs (loop0): encrypted files will use data=ordered instead of data journaling mode
EXT4-fs (loop0): 1 truncate cleaned up
======================================================
WARNING: possible circular locking dependency detected
6.6.95-syzkaller #0 Not tainted
------------------------------------------------------
syz.0.68/6050 is trying to acquire lock:
ffff888075375410 (&sb->s_type->i_mutex_key#8/1){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
ffff888075375410 (&sb->s_type->i_mutex_key#8/1){+.+.}-{3:3}, at: ext4_xattr_inode_create fs/ext4/xattr.c:1523 [inline]
ffff888075375410 (&sb->s_type->i_mutex_key#8/1){+.+.}-{3:3}, at: ext4_xattr_inode_lookup_create+0x1917/0x1d80 fs/ext4/xattr.c:1605

but task is already holding lock:
ffff888064570c88 (&ei->i_data_sem/3){++++}-{3:3}, at: ext4_setattr+0x15fa/0x1c90 fs/ext4/inode.c:5581

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&ei->i_data_sem/3){++++}-{3:3}:
       down_write+0x97/0x1f0 kernel/locking/rwsem.c:1573
       ext4_update_i_disksize fs/ext4/ext4.h:3382 [inline]
       ext4_xattr_inode_write fs/ext4/xattr.c:1461 [inline]
       ext4_xattr_inode_lookup_create+0x15fe/0x1d80 fs/ext4/xattr.c:1611
       ext4_xattr_ibody_set+0x202/0x6a0 fs/ext4/xattr.c:2273
       ext4_xattr_set_handle+0xaad/0x1290 fs/ext4/xattr.c:2450
       ext4_xattr_set+0x22d/0x320 fs/ext4/xattr.c:2564
       __vfs_setxattr+0x431/0x470 fs/xattr.c:201
       __vfs_setxattr_noperm+0x12d/0x5e0 fs/xattr.c:235
       vfs_setxattr+0x16c/0x2f0 fs/xattr.c:322
       do_setxattr fs/xattr.c:630 [inline]
       path_setxattr+0x362/0x550 fs/xattr.c:659
       __do_sys_setxattr fs/xattr.c:677 [inline]
       __se_sys_setxattr fs/xattr.c:673 [inline]
       __x64_sys_setxattr+0xbb/0xd0 fs/xattr.c:673
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #0 (&sb->s_type->i_mutex_key#8/1){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3134 [inline]
       check_prevs_add kernel/locking/lockdep.c:3253 [inline]
       validate_chain kernel/locking/lockdep.c:3869 [inline]
       __lock_acquire+0x2ddb/0x7c80 kernel/locking/lockdep.c:5137
       lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754
       down_write+0x97/0x1f0 kernel/locking/rwsem.c:1573
       inode_lock include/linux/fs.h:804 [inline]
       ext4_xattr_inode_create fs/ext4/xattr.c:1523 [inline]
       ext4_xattr_inode_lookup_create+0x1917/0x1d80 fs/ext4/xattr.c:1605
       ext4_xattr_block_set+0x23e/0x32a0 fs/ext4/xattr.c:1925
       ext4_xattr_move_to_block fs/ext4/xattr.c:2674 [inline]
       ext4_xattr_make_inode_space fs/ext4/xattr.c:2749 [inline]
       ext4_expand_extra_isize_ea+0x10ea/0x19e0 fs/ext4/xattr.c:2841
       __ext4_expand_extra_isize+0x306/0x400 fs/ext4/inode.c:5953
       ext4_try_to_expand_extra_isize fs/ext4/inode.c:5996 [inline]
       __ext4_mark_inode_dirty+0x45d/0x6e0 fs/ext4/inode.c:6074
       ext4_setattr+0x1673/0x1c90 fs/ext4/inode.c:5584
       notify_change+0xb0d/0xe10 fs/attr.c:499
       do_truncate+0x19b/0x220 fs/open.c:66
       handle_truncate fs/namei.c:3291 [inline]
       do_open fs/namei.c:3636 [inline]
       path_openat+0x298c/0x3190 fs/namei.c:3789
       do_filp_open+0x1c5/0x3d0 fs/namei.c:3816
       do_sys_openat2+0x12c/0x1c0 fs/open.c:1419
       do_sys_open fs/open.c:1434 [inline]
       __do_sys_openat fs/open.c:1450 [inline]
       __se_sys_openat fs/open.c:1445 [inline]
       __x64_sys_openat+0x139/0x160 fs/open.c:1445
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

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.0.68/6050:
 #0: ffff88802e6a2418 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:403
 #1: ffff888064570e10 (&sb->s_type->i_mutex_key#8){++++}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
 #1: ffff888064570e10 (&sb->s_type->i_mutex_key#8){++++}-{3:3}, at: do_truncate+0x187/0x220 fs/open.c:64
 #2: ffff888064570fa0 (mapping.invalidate_lock){++++}-{3:3}, at: filemap_invalidate_lock include/linux/fs.h:849 [inline]
 #2: ffff888064570fa0 (mapping.invalidate_lock){++++}-{3:3}, at: ext4_setattr+0xef3/0x1c90 fs/ext4/inode.c:5529
 #3: ffff888064570c88 (&ei->i_data_sem/3){++++}-{3:3}, at: ext4_setattr+0x15fa/0x1c90 fs/ext4/inode.c:5581
 #4: ffff888064570ac8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_write_trylock_xattr fs/ext4/xattr.h:162 [inline]
 #4: ffff888064570ac8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_try_to_expand_extra_isize fs/ext4/inode.c:5993 [inline]
 #4: ffff888064570ac8 (&ei->xattr_sem){++++}-{3:3}, at: __ext4_mark_inode_dirty+0x3dc/0x6e0 fs/ext4/inode.c:6074

stack backtrace:
CPU: 0 PID: 6050 Comm: syz.0.68 Not tainted 6.6.95-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
 check_noncircular+0x2bd/0x3c0 kernel/locking/lockdep.c:2187
 check_prev_add kernel/locking/lockdep.c:3134 [inline]
 check_prevs_add kernel/locking/lockdep.c:3253 [inline]
 validate_chain kernel/locking/lockdep.c:3869 [inline]
 __lock_acquire+0x2ddb/0x7c80 kernel/locking/lockdep.c:5137
 lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754
 down_write+0x97/0x1f0 kernel/locking/rwsem.c:1573
 inode_lock include/linux/fs.h:804 [inline]
 ext4_xattr_inode_create fs/ext4/xattr.c:1523 [inline]
 ext4_xattr_inode_lookup_create+0x1917/0x1d80 fs/ext4/xattr.c:1605
 ext4_xattr_block_set+0x23e/0x32a0 fs/ext4/xattr.c:1925
 ext4_xattr_move_to_block fs/ext4/xattr.c:2674 [inline]
 ext4_xattr_make_inode_space fs/ext4/xattr.c:2749 [inline]
 ext4_expand_extra_isize_ea+0x10ea/0x19e0 fs/ext4/xattr.c:2841
 __ext4_expand_extra_isize+0x306/0x400 fs/ext4/inode.c:5953
 ext4_try_to_expand_extra_isize fs/ext4/inode.c:5996 [inline]
 __ext4_mark_inode_dirty+0x45d/0x6e0 fs/ext4/inode.c:6074
 ext4_setattr+0x1673/0x1c90 fs/ext4/inode.c:5584
 notify_change+0xb0d/0xe10 fs/attr.c:499
 do_truncate+0x19b/0x220 fs/open.c:66
 handle_truncate fs/namei.c:3291 [inline]
 do_open fs/namei.c:3636 [inline]
 path_openat+0x298c/0x3190 fs/namei.c:3789
 do_filp_open+0x1c5/0x3d0 fs/namei.c:3816
 do_sys_openat2+0x12c/0x1c0 fs/open.c:1419
 do_sys_open fs/open.c:1434 [inline]
 __do_sys_openat fs/open.c:1450 [inline]
 __se_sys_openat fs/open.c:1445 [inline]
 __x64_sys_openat+0x139/0x160 fs/open.c:1445
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fa9e0f8e929
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fffc245c228 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fa9e11b5fa0 RCX: 00007fa9e0f8e929
RDX: 0000000000000242 RSI: 0000200000000040 RDI: ffffffffffffff9c
RBP: 00007fa9e1010b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa9e11b5fa0 R14: 00007fa9e11b5fa0 R15: 0000000000000004
 </TASK>