======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.4.443/9135 is trying to acquire lock:
ffff88816dfe9d38 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock_killable+0x1d/0x70

but task is already holding lock:
ffff8881012df980 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_fop_readdir+0x26d/0x960

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #4 (&root->kernfs_rwsem){++++}-{4:4}:
       down_write+0x96/0x200
       kernfs_add_one+0x41/0x5e0
       kernfs_create_dir_ns+0x1a1/0x230
       sysfs_create_dir_ns+0x12f/0x2a0
       kobject_add_internal+0x622/0xcd0
       kobject_init_and_add+0x12b/0x1a0
       btrfs_sysfs_add_qgroups+0x118/0x2f0
       btrfs_quota_enable+0x274/0x1e20
       btrfs_ioctl_quota_ctl+0x186/0x1f0
       __se_sys_ioctl+0xfc/0x170
       do_syscall_64+0x174/0x580
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #3 (&fs_info->qgroup_ioctl_lock){+.+.}-{4:4}:
       __mutex_lock+0x19d/0x1550
       btrfs_quota_enable+0x2b1/0x1e20
       btrfs_ioctl_quota_ctl+0x186/0x1f0
       __se_sys_ioctl+0xfc/0x170
       do_syscall_64+0x174/0x580
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #2 (btrfs_trans_num_extwriters){++++}-{0:0}:
       join_transaction+0x18a/0xd40
       start_transaction+0x74d/0x18b0
       btrfs_dirty_inode+0x9f/0x190
       touch_atime+0x2f8/0x670
       filemap_read+0xffc/0x11e0
       __kernel_read+0x4ca/0x960
       integrity_kernel_read+0x89/0xd0
       ima_calc_file_hash+0x451/0x890
       ima_collect_measurement+0x51b/0xa00
       process_measurement+0x1272/0x1c10
       ima_file_check+0xe1/0x130
       security_file_post_open+0xb3/0x260
       path_openat+0x2e90/0x3830
       do_file_open+0x23e/0x4a0
       do_sys_openat2+0x115/0x200
       __x64_sys_openat+0x138/0x170
       do_syscall_64+0x174/0x580
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #1 (btrfs_trans_num_writers){++++}-{0:0}:
       lock_release+0x199/0x3c0
       sb_end_intwrite+0x26/0x190
       __btrfs_end_transaction+0x23f/0x640
       btrfs_dirty_inode+0x14c/0x190
       touch_atime+0x2f8/0x670
       btrfs_file_mmap_prepare+0x172/0x1f0
       mmap_region+0xe5a/0x2310
       do_mmap+0xc3b/0x10c0
       vm_mmap_pgoff+0x272/0x4e0
       ksys_mmap_pgoff+0x4dc/0x760
       do_syscall_64+0x174/0x580
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (&mm->mmap_lock){++++}-{4:4}:
       __lock_acquire+0x1520/0x2cf0
       lock_acquire+0x106/0x350
       down_read_killable+0x50/0x3b0
       mmap_read_lock_killable+0x1d/0x70
       lock_mm_and_find_vma+0x2d6/0x340
       do_user_addr_fault+0x341/0x1340
       exc_page_fault+0x6a/0xc0
       asm_exc_page_fault+0x26/0x30
       filldir+0x2bd/0x630
       kernfs_fop_readdir+0x580/0x960
       iterate_dir+0x2e2/0x4d0
       __se_sys_getdents+0xf1/0x270
       do_syscall_64+0x174/0x580
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

Chain exists of:
  &mm->mmap_lock --> &fs_info->qgroup_ioctl_lock --> &root->kernfs_rwsem

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  rlock(&root->kernfs_rwsem);
                               lock(&fs_info->qgroup_ioctl_lock);
                               lock(&root->kernfs_rwsem);
  rlock(&mm->mmap_lock);

 *** DEADLOCK ***

3 locks held by syz.4.443/9135:
 #0: ffff88817551cef0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x246/0x320
 #1: ffff8881b8e4a280 (&type->i_mutex_dir_key#6){++++}-{4:4}, at: iterate_dir+0x209/0x4d0
 #2: ffff8881012df980 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_fop_readdir+0x26d/0x960

stack backtrace:
CPU: 0 UID: 0 PID: 9135 Comm: syz.4.443 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150
 print_circular_bug+0x2e1/0x300
 check_noncircular+0x12e/0x150
 __lock_acquire+0x1520/0x2cf0
 lock_acquire+0x106/0x350
 down_read_killable+0x50/0x3b0
 mmap_read_lock_killable+0x1d/0x70
 lock_mm_and_find_vma+0x2d6/0x340
 do_user_addr_fault+0x341/0x1340
 exc_page_fault+0x6a/0xc0
 asm_exc_page_fault+0x26/0x30
RIP: 0010:filldir+0x2bd/0x630
Code: c9 be 79 ff 0f 1f 00 48 8b 44 24 20 49 89 47 08 48 bd 00 00 00 00 00 fc ff df 48 8b 44 24 40 48 89 03 8b 4c 24 04 48 8d 43 10 <66> 89 08 8b 54 24 14 80 e2 0f 89 c9 48 8d 04 0b 48 ff c8 88 10 48
RSP: 0018:ffffc900059b7c50 EFLAGS: 00010297
RAX: 0000200000002000 RBX: 0000200000001ff0 RCX: 0000000000000028
RDX: ffff88816c510000 RSI: 000000000000000d RDI: 0000000000000007
RBP: dffffc0000000000 R08: ffff88816c510007 R09: 1ffff1102d8a2000
R10: dffffc0000000000 R11: ffffed102d8a2001 R12: ffff8881705552e0
R13: 000000000000000d R14: 000000000000000d R15: 0000200000001fd8
 kernfs_fop_readdir+0x580/0x960
 iterate_dir+0x2e2/0x4d0
 __se_sys_getdents+0xf1/0x270
 do_syscall_64+0x174/0x580
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4c4a99ce59
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f4c4b84a028 EFLAGS: 00000246 ORIG_RAX: 000000000000004e
RAX: ffffffffffffffda RBX: 00007f4c4ac15fa0 RCX: 00007f4c4a99ce59
RDX: 0000000020002078 RSI: 0000200000001fc0 RDI: 0000000000000003
RBP: 00007f4c4aa32e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4c4ac16038 R14: 00007f4c4ac15fa0 R15: 00007ffe2b4d8158
 </TASK>
overlayfs: failed to resolve './bus': -2
