syzbot

loop0: detected capacity change from 0 to 512
======================================================
WARNING: possible circular locking dependency detected
syzkaller[  104.885164][ T5933] syzkaller #0 Not tainted
------------------------------------------------------
syz.0.17/5933 is trying to acquire lock:
ffff888032f68cd8 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: percpu_down_read include/linux/percpu-rwsem.h:77 [inline]
ffff888032f68cd8 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1811 [inline]
ffff888032f68cd8 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x205/0x3b0 fs/ext4/inode.c:3041

but task is already holding lock:
ffff88804634a428 (&ei->xattr_sem){++++}-{4:4}, at: ext4_write_trylock_xattr fs/ext4/xattr.h:164 [inline]
ffff88804634a428 (&ei->xattr_sem){++++}-{4:4}, at: ext4_try_to_expand_extra_isize fs/ext4/inode.c:6474 [inline]
ffff88804634a428 (&ei->xattr_sem){++++}-{4:4}, at: __ext4_mark_inode_dirty+0x3db/0x710 fs/ext4/inode.c:6555

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (&ei->xattr_sem){++++}-{4:4}:
       down_write+0x3a/0x50 kernel/locking/rwsem.c:1625
       ext4_write_lock_xattr fs/ext4/xattr.h:157 [inline]
       ext4_xattr_set_handle+0x19c/0x14c0 fs/ext4/xattr.c:2374
       ext4_initxattrs+0x9f/0x110 fs/ext4/xattr_security.c:44
       security_inode_init_security+0x296/0x3d0 security/security.c:1370
       __ext4_new_inode+0x3319/0x3ce0 fs/ext4/ialloc.c:1330
       ext4_create+0x233/0x470 fs/ext4/namei.c:2827
       lookup_open fs/namei.c:4511 [inline]
       open_last_lookups fs/namei.c:4611 [inline]
       path_openat+0x13b4/0x38a0 fs/namei.c:4855
       do_file_open+0x23e/0x4a0 fs/namei.c:4887
       do_sys_openat2+0x113/0x200 fs/open.c:1364
       do_sys_open fs/open.c:1370 [inline]
       __do_sys_openat fs/open.c:1386 [inline]
       __se_sys_openat fs/open.c:1381 [inline]
       __x64_sys_openat+0x138/0x170 fs/open.c:1381
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #1 (jbd2_handle){++++}-{0:0}:
       wait_transaction_locked+0x1c2/0x280 fs/jbd2/transaction.c:151
       add_transaction_credits fs/jbd2/transaction.c:222 [inline]
       start_this_handle+0x7dc/0x2290 fs/jbd2/transaction.c:403
       jbd2__journal_start+0x2c0/0x5c0 fs/jbd2/transaction.c:502
       __ext4_journal_start_sb+0x203/0x5d0 fs/ext4/ext4_jbd2.c:114
       __ext4_journal_start fs/ext4/ext4_jbd2.h:242 [inline]
       ext4_do_writepages+0xf79/0x4670 fs/ext4/inode.c:2930
       ext4_writepages+0x241/0x3b0 fs/ext4/inode.c:3042
       do_writepages+0x32e/0x550 mm/page-writeback.c:2571
       __writeback_single_inode+0x133/0x10e0 fs/fs-writeback.c:1764
       writeback_sb_inodes+0x97f/0x1980 fs/fs-writeback.c:2056
       __writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:2132
       wb_writeback+0x459/0xb00 fs/fs-writeback.c:2243
       wb_check_old_data_flush fs/fs-writeback.c:2347 [inline]
       wb_do_writeback fs/fs-writeback.c:2400 [inline]
       wb_workfn+0xb17/0xf20 fs/fs-writeback.c:2428
       process_one_work kernel/workqueue.c:3302 [inline]
       process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3385
       worker_thread+0xa53/0xfc0 kernel/workqueue.c:3466
       kthread+0x388/0x470 kernel/kthread.c:436
       ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

-> #0 (&sbi->s_writepages_rwsem){++++}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3165 [inline]
       check_prevs_add kernel/locking/lockdep.c:3284 [inline]
       validate_chain kernel/locking/lockdep.c:3908 [inline]
       __lock_acquire+0x15a5/0x2cf0 kernel/locking/lockdep.c:5237
       lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868
       percpu_down_read_internal+0x48/0x1d0 include/linux/percpu-rwsem.h:53
       percpu_down_read include/linux/percpu-rwsem.h:77 [inline]
       ext4_writepages_down_read fs/ext4/ext4.h:1811 [inline]
       ext4_writepages+0x205/0x3b0 fs/ext4/inode.c:3041
       do_writepages+0x32e/0x550 mm/page-writeback.c:2571
       __writeback_single_inode+0x133/0x10e0 fs/fs-writeback.c:1764
       writeback_single_inode+0x488/0xd60 fs/fs-writeback.c:1883
       write_inode_now+0x1c2/0x290 fs/fs-writeback.c:2974
       iput_final fs/inode.c:1950 [inline]
       iput+0x8c1/0xe80 fs/inode.c:2009
       ext4_xattr_block_set+0x1fd4/0x2ad0 fs/ext4/xattr.c:2206
       ext4_xattr_move_to_block fs/ext4/xattr.c:2671 [inline]
       ext4_xattr_make_inode_space fs/ext4/xattr.c:2746 [inline]
       ext4_expand_extra_isize_ea+0x12cf/0x1ea0 fs/ext4/xattr.c:2834
       __ext4_expand_extra_isize+0x30d/0x400 fs/ext4/inode.c:6434
       ext4_try_to_expand_extra_isize fs/ext4/inode.c:6477 [inline]
       __ext4_mark_inode_dirty+0x45c/0x710 fs/ext4/inode.c:6555
       ext4_evict_inode+0x986/0x10e0 fs/ext4/inode.c:267
       evict+0x61e/0xb10 fs/inode.c:841
       ext4_orphan_cleanup+0xc38/0x1470 fs/ext4/orphan.c:472
       __ext4_fill_super fs/ext4/super.c:5701 [inline]
       ext4_fill_super+0x59bb/0x62d0 fs/ext4/super.c:5824
       get_tree_bdev_flags+0x431/0x4f0 fs/super.c:1694
       vfs_get_tree+0x92/0x2a0 fs/super.c:1754
       fc_mount fs/namespace.c:1193 [inline]
       do_new_mount_fc fs/namespace.c:3758 [inline]
       do_new_mount+0x341/0xd30 fs/namespace.c:3834
       do_mount fs/namespace.c:4167 [inline]
       __do_sys_mount fs/namespace.c:4383 [inline]
       __se_sys_mount+0x31d/0x420 fs/namespace.c:4360
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

Chain exists of:
  &sbi->s_writepages_rwsem --> jbd2_handle --> &ei->xattr_sem

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&ei->xattr_sem);
                               lock(jbd2_handle);
                               lock(&ei->xattr_sem);
  rlock(&sbi->s_writepages_rwsem);

 *** DEADLOCK ***

3 locks held by syz.0.17/5933:
 #0: ffff888039da60d0 (&type->s_umount_key#28/1){+.+.}-{4:4}, at: alloc_super+0x28c/0xac0 fs/super.c:345
 #1: ffff888039da6770 (sb_internal){.+.+}-{0:0}, at: percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline]
 #1: ffff888039da6770 (sb_internal){.+.+}-{0:0}, at: __sb_start_write include/linux/fs/super.h:19 [inline]
 #1: ffff888039da6770 (sb_internal){.+.+}-{0:0}, at: sb_start_intwrite include/linux/fs/super.h:177 [inline]
 #1: ffff888039da6770 (sb_internal){.+.+}-{0:0}, at: ext4_evict_inode+0x426/0x10e0 fs/ext4/inode.c:228
 #2: ffff88804634a428 (&ei->xattr_sem){++++}-{4:4}, at: ext4_write_trylock_xattr fs/ext4/xattr.h:164 [inline]
 #2: ffff88804634a428 (&ei->xattr_sem){++++}-{4:4}, at: ext4_try_to_expand_extra_isize fs/ext4/inode.c:6474 [inline]
 #2: ffff88804634a428 (&ei->xattr_sem){++++}-{4:4}, at: __ext4_mark_inode_dirty+0x3db/0x710 fs/ext4/inode.c:6555

stack backtrace:
CPU: 0 UID: 0 PID: 5933 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_circular_bug+0x2e1/0x300 kernel/locking/lockdep.c:2043
 check_noncircular+0x12e/0x150 kernel/locking/lockdep.c:2175
 check_prev_add kernel/locking/lockdep.c:3165 [inline]
 check_prevs_add kernel/locking/lockdep.c:3284 [inline]
 validate_chain kernel/locking/lockdep.c:3908 [inline]
 __lock_acquire+0x15a5/0x2cf0 kernel/locking/lockdep.c:5237
 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868
 percpu_down_read_internal+0x48/0x1d0 include/linux/percpu-rwsem.h:53
 percpu_down_read include/linux/percpu-rwsem.h:77 [inline]
 ext4_writepages_down_read fs/ext4/ext4.h:1811 [inline]
 ext4_writepages+0x205/0x3b0 fs/ext4/inode.c:3041
 do_writepages+0x32e/0x550 mm/page-writeback.c:2571
 __writeback_single_inode+0x133/0x10e0 fs/fs-writeback.c:1764
 writeback_single_inode+0x488/0xd60 fs/fs-writeback.c:1883
 write_inode_now+0x1c2/0x290 fs/fs-writeback.c:2974
 iput_final fs/inode.c:1950 [inline]
 iput+0x8c1/0xe80 fs/inode.c:2009
 ext4_xattr_block_set+0x1fd4/0x2ad0 fs/ext4/xattr.c:2206
 ext4_xattr_move_to_block fs/ext4/xattr.c:2671 [inline]
 ext4_xattr_make_inode_space fs/ext4/xattr.c:2746 [inline]
 ext4_expand_extra_isize_ea+0x12cf/0x1ea0 fs/ext4/xattr.c:2834
 __ext4_expand_extra_isize+0x30d/0x400 fs/ext4/inode.c:6434
 ext4_try_to_expand_extra_isize fs/ext4/inode.c:6477 [inline]
 __ext4_mark_inode_dirty+0x45c/0x710 fs/ext4/inode.c:6555
 ext4_evict_inode+0x986/0x10e0 fs/ext4/inode.c:267
 evict+0x61e/0xb10 fs/inode.c:841
 ext4_orphan_cleanup+0xc38/0x1470 fs/ext4/orphan.c:472
 __ext4_fill_super fs/ext4/super.c:5701 [inline]
 ext4_fill_super+0x59bb/0x62d0 fs/ext4/super.c:5824
 get_tree_bdev_flags+0x431/0x4f0 fs/super.c:1694
 vfs_get_tree+0x92/0x2a0 fs/super.c:1754
 fc_mount fs/namespace.c:1193 [inline]
 do_new_mount_fc fs/namespace.c:3758 [inline]
 do_new_mount+0x341/0xd30 fs/namespace.c:3834
 do_mount fs/namespace.c:4167 [inline]
 __do_sys_mount fs/namespace.c:4383 [inline]
 __se_sys_mount+0x31d/0x420 fs/namespace.c:4360
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe972a6e04a
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:00007fff6f24e6c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fff6f24e750 RCX: 00007fe972a6e04a
RDX: 0000200000000180 RSI: 0000200000000040 RDI: 00007fff6f24e710
RBP: 0000200000000180 R08: 00007fff6f24e750 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000200000000040
R13: 00007fff6f24e710 R14: 0000000000000485 R15: 0000200000000b40
 </TASK>
------------[ cut here ]------------
EA inode 11 i_nlink=65535
WARNING: fs/ext4/xattr.c:1059 at ext4_xattr_inode_update_ref+0x4c9/0x5a0 fs/ext4/xattr.c:1057, CPU#1: syz.0.17/5933
Modules linked in:
CPU: 1 UID: 0 PID: 5933 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:ext4_xattr_inode_update_ref+0x511/0x5a0 fs/ext4/xattr.c:1057
Code: 74 08 4c 89 ef e8 7f 30 9b ff 4d 8b 6d 00 48 b8 00 00 00 00 00 fc ff df 41 0f b6 04 06 84 c0 75 77 41 8b 17 4c 89 e7 4c 89 ee <67> 48 0f b9 3a 4c 8b 6c 24 28 e9 59 fe ff ff e8 7b 09 8c 08 44 89
RSP: 0018:ffffc90003b77100 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 00000000ffffffff RCX: dffffc0000000000
RDX: 000000000000ffff RSI: 000000000000000b RDI: ffffffff8f8f2f70
RBP: ffffc90003b77200 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed100b1c638e R12: ffffffff8f8f2f70
R13: 000000000000000b R14: 1ffff1100b1c6352 R15: ffff888058e31a90
FS:  0000555568a01500(0000) GS:ffff888126279000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7935ec4a90 CR3: 00000000431b4000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 ext4_xattr_inode_dec_ref fs/ext4/xattr.c:1082 [inline]
 ext4_xattr_set_entry+0xabb/0x1e20 fs/ext4/xattr.c:1726
 ext4_xattr_ibody_set+0x254/0x6a0 fs/ext4/xattr.c:2275
 ext4_xattr_move_to_block fs/ext4/xattr.c:2678 [inline]
 ext4_xattr_make_inode_space fs/ext4/xattr.c:2746 [inline]
 ext4_expand_extra_isize_ea+0x13a2/0x1ea0 fs/ext4/xattr.c:2834
 __ext4_expand_extra_isize+0x30d/0x400 fs/ext4/inode.c:6434
 ext4_try_to_expand_extra_isize fs/ext4/inode.c:6477 [inline]
 __ext4_mark_inode_dirty+0x45c/0x710 fs/ext4/inode.c:6555
 ext4_evict_inode+0x986/0x10e0 fs/ext4/inode.c:267
 evict+0x61e/0xb10 fs/inode.c:841
 ext4_orphan_cleanup+0xc38/0x1470 fs/ext4/orphan.c:472
 __ext4_fill_super fs/ext4/super.c:5701 [inline]
 ext4_fill_super+0x59bb/0x62d0 fs/ext4/super.c:5824
 get_tree_bdev_flags+0x431/0x4f0 fs/super.c:1694
 vfs_get_tree+0x92/0x2a0 fs/super.c:1754
 fc_mount fs/namespace.c:1193 [inline]
 do_new_mount_fc fs/namespace.c:3758 [inline]
 do_new_mount+0x341/0xd30 fs/namespace.c:3834
 do_mount fs/namespace.c:4167 [inline]
 __do_sys_mount fs/namespace.c:4383 [inline]
 __se_sys_mount+0x31d/0x420 fs/namespace.c:4360
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe972a6e04a
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:00007fff6f24e6c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fff6f24e750 RCX: 00007fe972a6e04a
RDX: 0000200000000180 RSI: 0000200000000040 RDI: 00007fff6f24e710
RBP: 0000200000000180 R08: 00007fff6f24e750 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000200000000040
R13: 00007fff6f24e710 R14: 0000000000000485 R15: 0000200000000b40
 </TASK>
----------------
Code disassembly (best guess):
   0:	74 08                	je     0xa
   2:	4c 89 ef             	mov    %r13,%rdi
   5:	e8 7f 30 9b ff       	call   0xff9b3089
   a:	4d 8b 6d 00          	mov    0x0(%r13),%r13
   e:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  15:	fc ff df
  18:	41 0f b6 04 06       	movzbl (%r14,%rax,1),%eax
  1d:	84 c0                	test   %al,%al
  1f:	75 77                	jne    0x98
  21:	41 8b 17             	mov    (%r15),%edx
  24:	4c 89 e7             	mov    %r12,%rdi
  27:	4c 89 ee             	mov    %r13,%rsi
* 2a:	67 48 0f b9 3a       	ud1    (%edx),%rdi <-- trapping instruction
  2f:	4c 8b 6c 24 28       	mov    0x28(%rsp),%r13
  34:	e9 59 fe ff ff       	jmp    0xfffffe92
  39:	e8 7b 09 8c 08       	call   0x88c09b9
  3e:	44                   	rex.R
  3f:	89                   	.byte 0x89