syzbot

loop0: detected capacity change from 0 to 1024
EXT4-fs: Warning: mounting with an experimental mount option 'dioread_nolock' for blocksize < PAGE_SIZE
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.0.74/6120 is trying to acquire lock:
ffff88805ee20410 (&sb->s_type->i_mutex_key#9/1){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
ffff88805ee20410 (&sb->s_type->i_mutex_key#9/1){+.+.}-{3:3}, at: ext4_xattr_inode_create fs/ext4/xattr.c:1528 [inline]
ffff88805ee20410 (&sb->s_type->i_mutex_key#9/1){+.+.}-{3:3}, at: ext4_xattr_inode_lookup_create+0x1917/0x1d80 fs/ext4/xattr.c:1610

but task is already holding lock:
ffff88805ee22088 (&ei->i_data_sem/3){++++}-{3:3}, at: ext4_setattr+0x15fa/0x1c90 fs/ext4/inode.c:5595

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:3392 [inline]
       ext4_xattr_inode_write fs/ext4/xattr.c:1466 [inline]
       ext4_xattr_inode_lookup_create+0x15fe/0x1d80 fs/ext4/xattr.c:1616
       ext4_xattr_ibody_set+0x202/0x6a0 fs/ext4/xattr.c:2278
       ext4_xattr_set_handle+0xaad/0x1290 fs/ext4/xattr.c:2455
       ext4_xattr_set+0x22d/0x320 fs/ext4/xattr.c:2569
       __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#9/1){+.+.}-{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:1528 [inline]
       ext4_xattr_inode_lookup_create+0x1917/0x1d80 fs/ext4/xattr.c:1610
       ext4_xattr_block_set+0x23e/0x32a0 fs/ext4/xattr.c:1930
       ext4_xattr_move_to_block fs/ext4/xattr.c:2679 [inline]
       ext4_xattr_make_inode_space fs/ext4/xattr.c:2754 [inline]
       ext4_expand_extra_isize_ea+0x10ea/0x19e0 fs/ext4/xattr.c:2846
       __ext4_expand_extra_isize+0x306/0x400 fs/ext4/inode.c:5967
       ext4_try_to_expand_extra_isize fs/ext4/inode.c:6010 [inline]
       __ext4_mark_inode_dirty+0x45d/0x6e0 fs/ext4/inode.c:6088
       ext4_setattr+0x1673/0x1c90 fs/ext4/inode.c:5598
       notify_change+0xb0d/0xe10 fs/attr.c:499
       do_truncate+0x19b/0x220 fs/open.c:66
       handle_truncate fs/namei.c:3299 [inline]
       do_open fs/namei.c:3644 [inline]
       path_openat+0x298c/0x3190 fs/namei.c:3797
       do_filp_open+0x1c5/0x3d0 fs/namei.c:3824
       do_sys_openat2+0x12c/0x1c0 fs/open.c:1419
       do_sys_open fs/open.c:1434 [inline]
       __do_sys_creat fs/open.c:1512 [inline]
       __se_sys_creat fs/open.c:1506 [inline]
       __x64_sys_creat+0x90/0xb0 fs/open.c:1506
       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#9/1);
                               lock(&ei->i_data_sem/3);
  lock(&sb->s_type->i_mutex_key#9/1);

 *** DEADLOCK ***

5 locks held by syz.0.74/6120:
 #0: ffff88802fe7e418 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:412
 #1: ffff88805ee22210 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
 #1: ffff88805ee22210 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: do_truncate+0x187/0x220 fs/open.c:64
 #2: ffff88805ee223a0 (mapping.invalidate_lock#2){++++}-{3:3}, at: filemap_invalidate_lock include/linux/fs.h:849 [inline]
 #2: ffff88805ee223a0 (mapping.invalidate_lock#2){++++}-{3:3}, at: ext4_setattr+0xef3/0x1c90 fs/ext4/inode.c:5543
 #3: ffff88805ee22088 (&ei->i_data_sem/3){++++}-{3:3}, at: ext4_setattr+0x15fa/0x1c90 fs/ext4/inode.c:5595
 #4: ffff88805ee21ec8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_write_trylock_xattr fs/ext4/xattr.h:162 [inline]
 #4: ffff88805ee21ec8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_try_to_expand_extra_isize fs/ext4/inode.c:6007 [inline]
 #4: ffff88805ee21ec8 (&ei->xattr_sem){++++}-{3:3}, at: __ext4_mark_inode_dirty+0x3dc/0x6e0 fs/ext4/inode.c:6088

stack backtrace:
CPU: 0 PID: 6120 Comm: syz.0.74 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
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:1528 [inline]
 ext4_xattr_inode_lookup_create+0x1917/0x1d80 fs/ext4/xattr.c:1610
 ext4_xattr_block_set+0x23e/0x32a0 fs/ext4/xattr.c:1930
 ext4_xattr_move_to_block fs/ext4/xattr.c:2679 [inline]
 ext4_xattr_make_inode_space fs/ext4/xattr.c:2754 [inline]
 ext4_expand_extra_isize_ea+0x10ea/0x19e0 fs/ext4/xattr.c:2846
 __ext4_expand_extra_isize+0x306/0x400 fs/ext4/inode.c:5967
 ext4_try_to_expand_extra_isize fs/ext4/inode.c:6010 [inline]
 __ext4_mark_inode_dirty+0x45d/0x6e0 fs/ext4/inode.c:6088
 ext4_setattr+0x1673/0x1c90 fs/ext4/inode.c:5598
 notify_change+0xb0d/0xe10 fs/attr.c:499
 do_truncate+0x19b/0x220 fs/open.c:66
 handle_truncate fs/namei.c:3299 [inline]
 do_open fs/namei.c:3644 [inline]
 path_openat+0x298c/0x3190 fs/namei.c:3797
 do_filp_open+0x1c5/0x3d0 fs/namei.c:3824
 do_sys_openat2+0x12c/0x1c0 fs/open.c:1419
 do_sys_open fs/open.c:1434 [inline]
 __do_sys_creat fs/open.c:1512 [inline]
 __se_sys_creat fs/open.c:1506 [inline]
 __x64_sys_creat+0x90/0xb0 fs/open.c:1506
 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: 0033:0x7f5aa738f6c9
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:00007ffdd903a008 EFLAGS: 00000246 ORIG_RAX: 0000000000000055
RAX: ffffffffffffffda RBX: 00007f5aa75e5fa0 RCX: 00007f5aa738f6c9
RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000200000000180
RBP: 00007f5aa7411f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5aa75e5fa0 R14: 00007f5aa75e5fa0 R15: 0000000000000002
 </TASK>
EXT4-fs error (device loop0): ext4_expand_extra_isize_ea:2802: inode #13: comm syz.0.74: corrupted in-inode xattr: bad magic number in in-inode xattr
EXT4-fs (loop0): Remounting filesystem read-only