loop0: detected capacity change from 0 to 512
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.0.195/6597 is trying to acquire lock:
ffff8880384ecc58 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: percpu_down_read include/linux/percpu-rwsem.h:77 [inline]
ffff8880384ecc58 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1796 [inline]
ffff8880384ecc58 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x1cc/0x350 fs/ext4/inode.c:3024

but task is already holding lock:
ffff88805e091868 (&ei->xattr_sem){++++}-{4:4}, at: ext4_write_trylock_xattr fs/ext4/xattr.h:164 [inline]
ffff88805e091868 (&ei->xattr_sem){++++}-{4:4}, at: ext4_try_to_expand_extra_isize fs/ext4/inode.c:6396 [inline]
ffff88805e091868 (&ei->xattr_sem){++++}-{4:4}, at: __ext4_mark_inode_dirty+0x3eb/0x700 fs/ext4/inode.c:6477

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&ei->xattr_sem){++++}-{4:4}:
       lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
       down_write+0x3a/0x50 kernel/locking/rwsem.c:1590
       ext4_write_lock_xattr fs/ext4/xattr.h:157 [inline]
       ext4_destroy_inline_data+0x28/0xe0 fs/ext4/inline.c:1787
       ext4_do_writepages+0x529/0x4600 fs/ext4/inode.c:2810
       ext4_writepages+0x205/0x350 fs/ext4/inode.c:3025
       do_writepages+0x32e/0x550 mm/page-writeback.c:2604
       __writeback_single_inode+0x145/0x1000 fs/fs-writeback.c:1719
       writeback_sb_inodes+0x6b7/0xf60 fs/fs-writeback.c:2015
       wb_writeback+0x43b/0xaf0 fs/fs-writeback.c:2195
       wb_do_writeback fs/fs-writeback.c:2342 [inline]
       wb_workfn+0x40e/0xf00 fs/fs-writeback.c:2382
       process_one_work kernel/workqueue.c:3263 [inline]
       process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346
       worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
       kthread+0x711/0x8a0 kernel/kthread.c:463
       ret_from_fork+0x4b9/0x870 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+0xb9b/0x2140 kernel/locking/lockdep.c:3908
       __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237
       lock_acquire+0x120/0x360 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:1796 [inline]
       ext4_writepages+0x1cc/0x350 fs/ext4/inode.c:3024
       do_writepages+0x32e/0x550 mm/page-writeback.c:2604
       __writeback_single_inode+0x145/0x1000 fs/fs-writeback.c:1719
       writeback_single_inode+0x1db/0x640 fs/fs-writeback.c:1840
       write_inode_now+0x160/0x1d0 fs/fs-writeback.c:2903
       iput_final fs/inode.c:1901 [inline]
       iput+0x830/0xc50 fs/inode.c:1966
       ext4_xattr_block_set+0x1fce/0x2ac0 fs/ext4/xattr.c:2199
       ext4_xattr_move_to_block fs/ext4/xattr.c:2664 [inline]
       ext4_xattr_make_inode_space fs/ext4/xattr.c:2739 [inline]
       ext4_expand_extra_isize_ea+0x12da/0x1ea0 fs/ext4/xattr.c:2827
       __ext4_expand_extra_isize+0x30d/0x400 fs/ext4/inode.c:6356
       ext4_try_to_expand_extra_isize fs/ext4/inode.c:6399 [inline]
       __ext4_mark_inode_dirty+0x46c/0x700 fs/ext4/inode.c:6477
       ext4_evict_inode+0x80d/0xee0 fs/ext4/inode.c:254
       evict+0x501/0x9c0 fs/inode.c:810
       ext4_orphan_cleanup+0xc20/0x1460 fs/ext4/orphan.c:470
       __ext4_fill_super fs/ext4/super.c:5617 [inline]
       ext4_fill_super+0x593b/0x61f0 fs/ext4/super.c:5736
       get_tree_bdev_flags+0x40e/0x4d0 fs/super.c:1691
       vfs_get_tree+0x92/0x2b0 fs/super.c:1751
       fc_mount fs/namespace.c:1208 [inline]
       do_new_mount_fc fs/namespace.c:3651 [inline]
       do_new_mount+0x302/0xa10 fs/namespace.c:3727
       do_mount fs/namespace.c:4050 [inline]
       __do_sys_mount fs/namespace.c:4238 [inline]
       __se_sys_mount+0x313/0x410 fs/namespace.c:4215
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0xfa/0xfa0 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->xattr_sem);
                               lock(&sbi->s_writepages_rwsem);
                               lock(&ei->xattr_sem);
  rlock(&sbi->s_writepages_rwsem);

 *** DEADLOCK ***

3 locks held by syz.0.195/6597:
 #0: ffff8880384ea0d0 (&type->s_umount_key#26/1){+.+.}-{4:4}, at: alloc_super+0x1ba/0x9a0 fs/super.c:344
 #1: ffff8880384ea770 (sb_internal){.+.+}-{0:0}, at: percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline]
 #1: ffff8880384ea770 (sb_internal){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1916 [inline]
 #1: ffff8880384ea770 (sb_internal){.+.+}-{0:0}, at: sb_start_intwrite include/linux/fs.h:2099 [inline]
 #1: ffff8880384ea770 (sb_internal){.+.+}-{0:0}, at: ext4_evict_inode+0x2d6/0xee0 fs/ext4/inode.c:215
 #2: ffff88805e091868 (&ei->xattr_sem){++++}-{4:4}, at: ext4_write_trylock_xattr fs/ext4/xattr.h:164 [inline]
 #2: ffff88805e091868 (&ei->xattr_sem){++++}-{4:4}, at: ext4_try_to_expand_extra_isize fs/ext4/inode.c:6396 [inline]
 #2: ffff88805e091868 (&ei->xattr_sem){++++}-{4:4}, at: __ext4_mark_inode_dirty+0x3eb/0x700 fs/ext4/inode.c:6477

stack backtrace:
CPU: 1 UID: 0 PID: 6597 Comm: syz.0.195 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_circular_bug+0x2ee/0x310 kernel/locking/lockdep.c:2043
 check_noncircular+0x134/0x160 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+0xb9b/0x2140 kernel/locking/lockdep.c:3908
 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237
 lock_acquire+0x120/0x360 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:1796 [inline]
 ext4_writepages+0x1cc/0x350 fs/ext4/inode.c:3024
 do_writepages+0x32e/0x550 mm/page-writeback.c:2604
 __writeback_single_inode+0x145/0x1000 fs/fs-writeback.c:1719
 writeback_single_inode+0x1db/0x640 fs/fs-writeback.c:1840
 write_inode_now+0x160/0x1d0 fs/fs-writeback.c:2903
 iput_final fs/inode.c:1901 [inline]
 iput+0x830/0xc50 fs/inode.c:1966
 ext4_xattr_block_set+0x1fce/0x2ac0 fs/ext4/xattr.c:2199
 ext4_xattr_move_to_block fs/ext4/xattr.c:2664 [inline]
 ext4_xattr_make_inode_space fs/ext4/xattr.c:2739 [inline]
 ext4_expand_extra_isize_ea+0x12da/0x1ea0 fs/ext4/xattr.c:2827
 __ext4_expand_extra_isize+0x30d/0x400 fs/ext4/inode.c:6356
 ext4_try_to_expand_extra_isize fs/ext4/inode.c:6399 [inline]
 __ext4_mark_inode_dirty+0x46c/0x700 fs/ext4/inode.c:6477
 ext4_evict_inode+0x80d/0xee0 fs/ext4/inode.c:254
 evict+0x501/0x9c0 fs/inode.c:810
 ext4_orphan_cleanup+0xc20/0x1460 fs/ext4/orphan.c:470
 __ext4_fill_super fs/ext4/super.c:5617 [inline]
 ext4_fill_super+0x593b/0x61f0 fs/ext4/super.c:5736
 get_tree_bdev_flags+0x40e/0x4d0 fs/super.c:1691
 vfs_get_tree+0x92/0x2b0 fs/super.c:1751
 fc_mount fs/namespace.c:1208 [inline]
 do_new_mount_fc fs/namespace.c:3651 [inline]
 do_new_mount+0x302/0xa10 fs/namespace.c:3727
 do_mount fs/namespace.c:4050 [inline]
 __do_sys_mount fs/namespace.c:4238 [inline]
 __se_sys_mount+0x313/0x410 fs/namespace.c:4215
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd08708066a
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fd0852e5e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fd0852e5ef0 RCX: 00007fd08708066a
RDX: 0000200000000180 RSI: 00002000000001c0 RDI: 00007fd0852e5eb0
RBP: 0000200000000180 R08: 00007fd0852e5ef0 R09: 0000000000800700
R10: 0000000000800700 R11: 0000000000000246 R12: 00002000000001c0
R13: 00007fd0852e5eb0 R14: 0000000000000473 R15: 0000200000000680
 </TASK>
------------[ cut here ]------------
EA inode 11 i_nlink=2
WARNING: CPU: 0 PID: 6597 at fs/ext4/xattr.c:1058 ext4_xattr_inode_update_ref+0x51a/0x5b0 fs/ext4/xattr.c:1056
Modules linked in:
CPU: 0 UID: 0 PID: 6597 Comm: syz.0.195 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:ext4_xattr_inode_update_ref+0x51a/0x5b0 fs/ext4/xattr.c:1056
Code: 48 b8 00 00 00 00 00 fc ff df 41 0f b6 04 06 84 c0 0f 85 80 00 00 00 41 8b 17 48 c7 c7 c0 98 ff 8a 4c 89 e6 e8 a7 b8 03 ff 90 <0f> 0b 90 90 4c 8b 6c 24 28 e9 59 fe ff ff e8 63 93 46 08 44 89 f9
RSP: 0018:ffffc9000d347100 EFLAGS: 00010246
RAX: 47b7d416af1c1a00 RBX: 0000000000000001 RCX: 0000000000080000
RDX: ffffc90005c51000 RSI: 000000000002dfe9 RDI: 000000000002dfea
RBP: ffffc9000d3471f8 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed101710487b R12: 000000000000000b
R13: ffff88805e14bf88 R14: 1ffff1100bc297d7 R15: ffff88805e14beb8
FS:  00007fd0852e66c0(0000) GS:ffff888126bcd000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc057801000 CR3: 0000000054ec2000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 ext4_xattr_inode_dec_ref fs/ext4/xattr.c:1081 [inline]
 ext4_xattr_set_entry+0xabb/0x1e20 fs/ext4/xattr.c:1719
 ext4_xattr_ibody_set+0x254/0x6a0 fs/ext4/xattr.c:2268
 ext4_xattr_move_to_block fs/ext4/xattr.c:2671 [inline]
 ext4_xattr_make_inode_space fs/ext4/xattr.c:2739 [inline]
 ext4_expand_extra_isize_ea+0x13ad/0x1ea0 fs/ext4/xattr.c:2827
 __ext4_expand_extra_isize+0x30d/0x400 fs/ext4/inode.c:6356
 ext4_try_to_expand_extra_isize fs/ext4/inode.c:6399 [inline]
 __ext4_mark_inode_dirty+0x46c/0x700 fs/ext4/inode.c:6477
 ext4_evict_inode+0x80d/0xee0 fs/ext4/inode.c:254
 evict+0x501/0x9c0 fs/inode.c:810
 ext4_orphan_cleanup+0xc20/0x1460 fs/ext4/orphan.c:470
 __ext4_fill_super fs/ext4/super.c:5617 [inline]
 ext4_fill_super+0x593b/0x61f0 fs/ext4/super.c:5736
 get_tree_bdev_flags+0x40e/0x4d0 fs/super.c:1691
 vfs_get_tree+0x92/0x2b0 fs/super.c:1751
 fc_mount fs/namespace.c:1208 [inline]
 do_new_mount_fc fs/namespace.c:3651 [inline]
 do_new_mount+0x302/0xa10 fs/namespace.c:3727
 do_mount fs/namespace.c:4050 [inline]
 __do_sys_mount fs/namespace.c:4238 [inline]
 __se_sys_mount+0x313/0x410 fs/namespace.c:4215
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd08708066a
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fd0852e5e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fd0852e5ef0 RCX: 00007fd08708066a
RDX: 0000200000000180 RSI: 00002000000001c0 RDI: 00007fd0852e5eb0
RBP: 0000200000000180 R08: 00007fd0852e5ef0 R09: 0000000000800700
R10: 0000000000800700 R11: 0000000000000246 R12: 00002000000001c0
R13: 00007fd0852e5eb0 R14: 0000000000000473 R15: 0000200000000680
 </TASK>