loop4: detected capacity change from 0 to 512
EXT4-fs (loop4): Ignoring removed nobh option
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.4.259/5524 is trying to acquire lock:
ffff888064a7ec58 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x213/0x2d40 fs/ext4/inode.c:2691

but task is already holding lock:
ffff888064a7c650 (sb_internal){++++}-{0:0}, at: __sb_start_write include/linux/fs.h:1811 [inline]
ffff888064a7c650 (sb_internal){++++}-{0:0}, at: sb_start_intwrite include/linux/fs.h:1928 [inline]
ffff888064a7c650 (sb_internal){++++}-{0:0}, at: ext4_evict_inode+0x41f/0x1050 fs/ext4/inode.c:245

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (sb_internal){++++}-{0:0}:
       percpu_down_read+0x46/0x1b0 include/linux/percpu-rwsem.h:51
       __sb_start_write include/linux/fs.h:1811 [inline]
       sb_start_intwrite include/linux/fs.h:1928 [inline]
       ext4_evict_inode+0x41f/0x1050 fs/ext4/inode.c:245
       evict+0x4b6/0x8b0 fs/inode.c:647
       ext4_ext_migrate+0xc07/0xe50 fs/ext4/migrate.c:588
       __ext4_ioctl fs/ext4/ioctl.c:1037 [inline]
       ext4_ioctl+0x1a84/0x3840 fs/ext4/ioctl.c:1291
       vfs_ioctl fs/ioctl.c:51 [inline]
       __do_sys_ioctl fs/ioctl.c:874 [inline]
       __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:860
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

-> #0 (&sbi->s_writepages_rwsem){++++}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3053 [inline]
       check_prevs_add kernel/locking/lockdep.c:3172 [inline]
       validate_chain kernel/locking/lockdep.c:3788 [inline]
       __lock_acquire+0x2c66/0x7b50 kernel/locking/lockdep.c:5012
       lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623
       percpu_down_read+0x46/0x1b0 include/linux/percpu-rwsem.h:51
       ext4_writepages+0x213/0x2d40 fs/ext4/inode.c:2691
       do_writepages+0x493/0x700 mm/page-writeback.c:2386
       __writeback_single_inode+0x153/0xda0 fs/fs-writeback.c:1657
       writeback_single_inode+0x3d2/0x8e0 fs/fs-writeback.c:1770
       write_inode_now+0x23b/0x2c0 fs/fs-writeback.c:2817
       iput_final fs/inode.c:1756 [inline]
       iput+0x599/0x880 fs/inode.c:1795
       ext4_xattr_set_entry+0x1d76/0x3f70 fs/ext4/xattr.c:1827
       ext4_xattr_block_set+0x4d7/0x2ce0 fs/ext4/xattr.c:1926
       ext4_xattr_move_to_block fs/ext4/xattr.c:2620 [inline]
       ext4_xattr_make_inode_space fs/ext4/xattr.c:2695 [inline]
       ext4_expand_extra_isize_ea+0xebe/0x18e0 fs/ext4/xattr.c:2783
       __ext4_expand_extra_isize+0x301/0x3e0 fs/ext4/inode.c:5924
       ext4_try_to_expand_extra_isize fs/ext4/inode.c:5967 [inline]
       __ext4_mark_inode_dirty+0x444/0x6c0 fs/ext4/inode.c:6045
       ext4_evict_inode+0xa55/0x1050 fs/ext4/inode.c:284
       evict+0x4b6/0x8b0 fs/inode.c:647
       ext4_orphan_cleanup+0xad8/0x1320 fs/ext4/orphan.c:472
       ext4_fill_super+0x8c65/0x93f0 fs/ext4/super.c:5006
       mount_bdev+0x28a/0x3c0 fs/super.c:1400
       legacy_get_tree+0xe6/0x180 fs/fs_context.c:611
       vfs_get_tree+0x88/0x270 fs/super.c:1530
       do_new_mount+0x247/0xa40 fs/namespace.c:3034
       do_mount fs/namespace.c:3377 [inline]
       __do_sys_mount fs/namespace.c:3585 [inline]
       __se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3562
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(sb_internal);
                               lock(
&sbi->s_writepages_rwsem);
                               lock(sb_internal);
  lock(&sbi->s_writepages_rwsem);

 *** DEADLOCK ***

3 locks held by syz.4.259/5524:
 #0: ffff888064a7c0e0
 (&type->s_umount_key#28/1){+.+.}-{3:3}
, at: alloc_super+0x200/0x970 fs/super.c:229
 #1: ffff888064a7c650 (sb_internal){++++}-{0:0}, at: __sb_start_write include/linux/fs.h:1811 [inline]
 #1: ffff888064a7c650 (sb_internal){++++}-{0:0}, at: sb_start_intwrite include/linux/fs.h:1928 [inline]
 #1: ffff888064a7c650 (sb_internal){++++}-{0:0}, at: ext4_evict_inode+0x41f/0x1050 fs/ext4/inode.c:245
 #2: ffff888074b314b8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_write_trylock_xattr fs/ext4/xattr.h:165 [inline]
 #2: ffff888074b314b8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_try_to_expand_extra_isize fs/ext4/inode.c:5964 [inline]
 #2: ffff888074b314b8 (&ei->xattr_sem){++++}-{3:3}, at: __ext4_mark_inode_dirty+0x3bd/0x6c0 fs/ext4/inode.c:6045

stack backtrace:
CPU: 0 PID: 5524 Comm: syz.4.259 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 check_noncircular+0x296/0x330 kernel/locking/lockdep.c:2133
 check_prev_add kernel/locking/lockdep.c:3053 [inline]
 check_prevs_add kernel/locking/lockdep.c:3172 [inline]
 validate_chain kernel/locking/lockdep.c:3788 [inline]
 __lock_acquire+0x2c66/0x7b50 kernel/locking/lockdep.c:5012
 lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623
 percpu_down_read+0x46/0x1b0 include/linux/percpu-rwsem.h:51
 ext4_writepages+0x213/0x2d40 fs/ext4/inode.c:2691
 do_writepages+0x493/0x700 mm/page-writeback.c:2386
 __writeback_single_inode+0x153/0xda0 fs/fs-writeback.c:1657
 writeback_single_inode+0x3d2/0x8e0 fs/fs-writeback.c:1770
 write_inode_now+0x23b/0x2c0 fs/fs-writeback.c:2817
 iput_final fs/inode.c:1756 [inline]
 iput+0x599/0x880 fs/inode.c:1795
 ext4_xattr_set_entry+0x1d76/0x3f70 fs/ext4/xattr.c:1827
 ext4_xattr_block_set+0x4d7/0x2ce0 fs/ext4/xattr.c:1926
 ext4_xattr_move_to_block fs/ext4/xattr.c:2620 [inline]
 ext4_xattr_make_inode_space fs/ext4/xattr.c:2695 [inline]
 ext4_expand_extra_isize_ea+0xebe/0x18e0 fs/ext4/xattr.c:2783
 __ext4_expand_extra_isize+0x301/0x3e0 fs/ext4/inode.c:5924
 ext4_try_to_expand_extra_isize fs/ext4/inode.c:5967 [inline]
 __ext4_mark_inode_dirty+0x444/0x6c0 fs/ext4/inode.c:6045
 ext4_evict_inode+0xa55/0x1050 fs/ext4/inode.c:284
 evict+0x4b6/0x8b0 fs/inode.c:647
 ext4_orphan_cleanup+0xad8/0x1320 fs/ext4/orphan.c:472
 ext4_fill_super+0x8c65/0x93f0 fs/ext4/super.c:5006
 mount_bdev+0x28a/0x3c0 fs/super.c:1400
 legacy_get_tree+0xe6/0x180 fs/fs_context.c:611
 vfs_get_tree+0x88/0x270 fs/super.c:1530
 do_new_mount+0x247/0xa40 fs/namespace.c:3034
 do_mount fs/namespace.c:3377 [inline]
 __do_sys_mount fs/namespace.c:3585 [inline]
 __se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3562
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f95a423910a
Code: 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f95a248fe58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f95a248fee0 RCX: 00007f95a423910a
RDX: 0000200000000180 RSI: 0000200000000140 RDI: 00007f95a248fea0
RBP: 0000200000000180 R08: 00007f95a248fee0 R09: 0000000000800718
R10: 0000000000800718 R11: 0000000000000246 R12: 0000200000000140
R13: 00007f95a248fea0 R14: 00000000000004a7 R15: 00002000000003c0
 </TASK>
------------[ cut here ]------------
EA inode 11 i_nlink=1026
WARNING: CPU: 1 PID: 5524 at fs/ext4/xattr.c:1006 ext4_xattr_inode_update_ref+0x4fe/0x560 fs/ext4/xattr.c:1004
Modules linked in:
CPU: 0 PID: 5524 Comm: syz.4.259 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
RIP: 0010:ext4_xattr_inode_update_ref+0x4fe/0x560 fs/ext4/xattr.c:1004
Code: 40 4c 89 e0 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 e7 e8 75 08 a2 ff 49 8b 34 24 48 c7 c7 00 99 3d 8a 44 89 fa e8 f2 0d 99 07 <0f> 0b 49 bd 00 00 00 00 00 fc ff df 4c 8b 74 24 08 4c 8b 64 24 10
RSP: 0018:ffffc900045ef180 EFLAGS: 00010246
RAX: 4e70e79364bbff00 RBX: ffff88805f63de50 RCX: 0000000000080000
RDX: ffffc9000bf61000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc900045ef270 R08: ffff8880b912795b R09: 1ffff11017224f2b
R10: dffffc0000000000 R11: ffffed1017224f2c R12: ffff88805f63dc98
R13: dffffc0000000000 R14: ffff88805f63dc58 R15: 0000000000000402
FS:  00007f95a24906c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f623416ed58 CR3: 00000000624ae000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 ext4_xattr_inode_dec_ref fs/ext4/xattr.c:1029 [inline]
 ext4_xattr_set_entry+0xb48/0x3f70 fs/ext4/xattr.c:1687
 ext4_xattr_ibody_set+0x113/0x330 fs/ext4/xattr.c:2240
 ext4_xattr_move_to_block fs/ext4/xattr.c:2627 [inline]
 ext4_xattr_make_inode_space fs/ext4/xattr.c:2695 [inline]
 ext4_expand_extra_isize_ea+0xf0d/0x18e0 fs/ext4/xattr.c:2783
 __ext4_expand_extra_isize+0x301/0x3e0 fs/ext4/inode.c:5924
 ext4_try_to_expand_extra_isize fs/ext4/inode.c:5967 [inline]
 __ext4_mark_inode_dirty+0x444/0x6c0 fs/ext4/inode.c:6045
 ext4_evict_inode+0xa55/0x1050 fs/ext4/inode.c:284
 evict+0x4b6/0x8b0 fs/inode.c:647
 ext4_orphan_cleanup+0xad8/0x1320 fs/ext4/orphan.c:472
 ext4_fill_super+0x8c65/0x93f0 fs/ext4/super.c:5006
 mount_bdev+0x28a/0x3c0 fs/super.c:1400
 legacy_get_tree+0xe6/0x180 fs/fs_context.c:611
 vfs_get_tree+0x88/0x270 fs/super.c:1530
 do_new_mount+0x247/0xa40 fs/namespace.c:3034
 do_mount fs/namespace.c:3377 [inline]
 __do_sys_mount fs/namespace.c:3585 [inline]
 __se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3562
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f95a423910a
Code: 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f95a248fe58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f95a248fee0 RCX: 00007f95a423910a
RDX: 0000200000000180 RSI: 0000200000000140 RDI: 00007f95a248fea0
RBP: 0000200000000180 R08: 00007f95a248fee0 R09: 0000000000800718
R10: 0000000000800718 R11: 0000000000000246 R12: 0000200000000140
R13: 00007f95a248fea0 R14: 00000000000004a7 R15: 00002000000003c0
 </TASK>