syzbot

loop0: detected capacity change from 0 to 512
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.0.17/5965 is trying to acquire lock:
ffff888030ec2c58 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: percpu_down_read include/linux/percpu-rwsem.h:77 [inline]
ffff888030ec2c58 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1796 [inline]
ffff888030ec2c58 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x1cc/0x350 fs/ext4/inode.c:3020

but task is already holding lock:
ffff888054501868 (&ei->xattr_sem){++++}-{4:4}, at: ext4_write_trylock_xattr fs/ext4/xattr.h:164 [inline]
ffff888054501868 (&ei->xattr_sem){++++}-{4:4}, at: ext4_try_to_expand_extra_isize fs/ext4/inode.c:6400 [inline]
ffff888054501868 (&ei->xattr_sem){++++}-{4:4}, at: __ext4_mark_inode_dirty+0x3db/0x6e0 fs/ext4/inode.c:6481

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:1590
       ext4_write_lock_xattr fs/ext4/xattr.h:157 [inline]
       ext4_xattr_set_handle+0x165/0x1590 fs/ext4/xattr.c:2367
       ext4_initxattrs+0x9f/0x110 fs/ext4/xattr_security.c:44
       security_inode_init_security+0x290/0x3d0 security/security.c:1344
       __ext4_new_inode+0x32f7/0x3c90 fs/ext4/ialloc.c:1325
       ext4_create+0x22d/0x460 fs/ext4/namei.c:2822
       lookup_open fs/namei.c:4440 [inline]
       open_last_lookups fs/namei.c:4540 [inline]
       path_openat+0x18d1/0x3df0 fs/namei.c:4784
       do_filp_open+0x1fa/0x410 fs/namei.c:4814
       do_sys_openat2+0x121/0x200 fs/open.c:1430
       do_sys_open fs/open.c:1436 [inline]
       __do_sys_openat fs/open.c:1452 [inline]
       __se_sys_openat fs/open.c:1447 [inline]
       __x64_sys_openat+0x138/0x170 fs/open.c:1447
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #1 (jbd2_handle){++++}-{0:0}:
       start_this_handle+0x1fa7/0x21c0 fs/jbd2/transaction.c:444
       jbd2__journal_start+0x2c1/0x5b0 fs/jbd2/transaction.c:501
       __ext4_journal_start_sb+0x203/0x580 fs/ext4/ext4_jbd2.c:115
       __ext4_journal_start fs/ext4/ext4_jbd2.h:242 [inline]
       ext4_do_writepages+0xf6f/0x45a0 fs/ext4/inode.c:2909
       ext4_writepages+0x205/0x350 fs/ext4/inode.c:3021
       do_writepages+0x32e/0x550 mm/page-writeback.c:2598
       __writeback_single_inode+0x133/0x1240 fs/fs-writeback.c:1737
       writeback_sb_inodes+0x8c8/0x1840 fs/fs-writeback.c:2030
       __writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:2107
       wb_writeback+0x43f/0xaa0 fs/fs-writeback.c:2218
       wb_check_old_data_flush fs/fs-writeback.c:2322 [inline]
       wb_do_writeback fs/fs-writeback.c:2375 [inline]
       wb_workfn+0xad7/0xee0 fs/fs-writeback.c:2403
       process_one_work kernel/workqueue.c:3257 [inline]
       process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
       worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
       kthread+0x711/0x8a0 kernel/kthread.c:463
       ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246

-> #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+0x15a6/0x2cf0 kernel/locking/lockdep.c:5237
       lock_acquire+0x117/0x340 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:3020
       do_writepages+0x32e/0x550 mm/page-writeback.c:2598
       __writeback_single_inode+0x133/0x1240 fs/fs-writeback.c:1737
       writeback_single_inode+0x488/0xd60 fs/fs-writeback.c:1858
       write_inode_now+0x160/0x1d0 fs/fs-writeback.c:2924
       iput_final fs/inode.c:1941 [inline]
       iput+0xa77/0x1030 fs/inode.c:2003
       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:6360
       ext4_try_to_expand_extra_isize fs/ext4/inode.c:6403 [inline]
       __ext4_mark_inode_dirty+0x45c/0x6e0 fs/ext4/inode.c:6481
       ext4_evict_inode+0x79c/0xe60 fs/ext4/inode.c:253
       evict+0x5f4/0xae0 fs/inode.c:837
       ext4_orphan_cleanup+0xc20/0x1460 fs/ext4/orphan.c:470
       __ext4_fill_super fs/ext4/super.c:5617 [inline]
       ext4_fill_super+0x5930/0x61f0 fs/ext4/super.c:5736
       get_tree_bdev_flags+0x40e/0x4d0 fs/super.c:1699
       vfs_get_tree+0x92/0x2a0 fs/super.c:1759
       fc_mount fs/namespace.c:1199 [inline]
       do_new_mount_fc fs/namespace.c:3636 [inline]
       do_new_mount+0x302/0xa10 fs/namespace.c:3712
       do_mount fs/namespace.c:4035 [inline]
       __do_sys_mount fs/namespace.c:4224 [inline]
       __se_sys_mount+0x313/0x410 fs/namespace.c:4201
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0xfa/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.0.17/5965:
 #0: ffff888030ec00d0 (&type->s_umount_key#27/1){+.+.}-{4:4}, at: alloc_super+0x28c/0xab0 fs/super.c:344
 #1: ffff888030ec0770 (sb_internal){.+.+}-{0:0}, at: percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline]
 #1: ffff888030ec0770 (sb_internal){.+.+}-{0:0}, at: __sb_start_write include/linux/fs/super.h:19 [inline]
 #1: ffff888030ec0770 (sb_internal){.+.+}-{0:0}, at: sb_start_intwrite include/linux/fs/super.h:177 [inline]
 #1: ffff888030ec0770 (sb_internal){.+.+}-{0:0}, at: ext4_evict_inode+0x26f/0xe60 fs/ext4/inode.c:214
 #2: ffff888054501868 (&ei->xattr_sem){++++}-{4:4}, at: ext4_write_trylock_xattr fs/ext4/xattr.h:164 [inline]
 #2: ffff888054501868 (&ei->xattr_sem){++++}-{4:4}, at: ext4_try_to_expand_extra_isize fs/ext4/inode.c:6400 [inline]
 #2: ffff888054501868 (&ei->xattr_sem){++++}-{4:4}, at: __ext4_mark_inode_dirty+0x3db/0x6e0 fs/ext4/inode.c:6481

stack backtrace:
CPU: 0 UID: 0 PID: 5965 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_circular_bug+0x2e2/0x300 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+0x15a6/0x2cf0 kernel/locking/lockdep.c:5237
 lock_acquire+0x117/0x340 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:3020
 do_writepages+0x32e/0x550 mm/page-writeback.c:2598
 __writeback_single_inode+0x133/0x1240 fs/fs-writeback.c:1737
 writeback_single_inode+0x488/0xd60 fs/fs-writeback.c:1858
 write_inode_now+0x160/0x1d0 fs/fs-writeback.c:2924
 iput_final fs/inode.c:1941 [inline]
 iput+0xa77/0x1030 fs/inode.c:2003
 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:6360
 ext4_try_to_expand_extra_isize fs/ext4/inode.c:6403 [inline]
 __ext4_mark_inode_dirty+0x45c/0x6e0 fs/ext4/inode.c:6481
 ext4_evict_inode+0x79c/0xe60 fs/ext4/inode.c:253
 evict+0x5f4/0xae0 fs/inode.c:837
 ext4_orphan_cleanup+0xc20/0x1460 fs/ext4/orphan.c:470
 __ext4_fill_super fs/ext4/super.c:5617 [inline]
 ext4_fill_super+0x5930/0x61f0 fs/ext4/super.c:5736
 get_tree_bdev_flags+0x40e/0x4d0 fs/super.c:1699
 vfs_get_tree+0x92/0x2a0 fs/super.c:1759
 fc_mount fs/namespace.c:1199 [inline]
 do_new_mount_fc fs/namespace.c:3636 [inline]
 do_new_mount+0x302/0xa10 fs/namespace.c:3712
 do_mount fs/namespace.c:4035 [inline]
 __do_sys_mount fs/namespace.c:4224 [inline]
 __se_sys_mount+0x313/0x410 fs/namespace.c:4201
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0db7080eea
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:00007ffccef48d28 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ffccef48db0 RCX: 00007f0db7080eea
RDX: 0000200000000180 RSI: 00002000000001c0 RDI: 00007ffccef48d70
RBP: 0000200000000180 R08: 00007ffccef48db0 R09: 0000000000800700
R10: 0000000000800700 R11: 0000000000000246 R12: 00002000000001c0
R13: 00007ffccef48d70 R14: 0000000000000472 R15: 000000000000002c
 </TASK>
EXT4-fs error (device loop0): ext4_xattr_inode_iget:441: inode #11: comm syz.0.17: iget: bad extra_isize 90 (inode size 256)
EXT4-fs (loop0): Remounting filesystem read-only
EXT4-fs warning (device loop0): ext4_expand_extra_isize_ea:2853: Unable to expand inode 15. Delete some EAs or run e2fsck.
EXT4-fs warning (device loop0): ext4_evict_inode:256: couldn't mark inode dirty (err -30)
EXT4-fs (loop0): 1 orphan inode deleted
EXT4-fs (loop0): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: none.