======================================================
WARNING: possible circular locking dependency detected
6.1.147-syzkaller #0 Not tainted
------------------------------------------------------
syz.5.1009/7019 is trying to acquire lock:
ffff888072a39698 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_map_blocks+0x316/0x1b60 fs/ext4/inode.c:604

but task is already holding lock:
ffff88802426a208 (&s->s_dquot.dqio_sem){++++}-{3:3}, at: v2_write_dquot+0x12b/0x190 fs/quota/quota_v2.c:357

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (&s->s_dquot.dqio_sem){++++}-{3:3}:
       down_read+0x42/0x2d0 kernel/locking/rwsem.c:1520
       v2_read_dquot+0x4a/0x110 fs/quota/quota_v2.c:335
       dquot_acquire+0x152/0x520 fs/quota/dquot.c:463
       ext4_acquire_dquot+0x2d9/0x4a0 fs/ext4/super.c:6810
       dqget+0x778/0xeb0 fs/quota/dquot.c:988
       __dquot_initialize+0x3b6/0xcb0 fs/quota/dquot.c:1517
       ext4_process_orphan+0x54/0x300 fs/ext4/orphan.c:329
       ext4_orphan_cleanup+0xbd3/0x1400 fs/ext4/orphan.c:474
       __ext4_fill_super fs/ext4/super.c:5535 [inline]
       ext4_fill_super+0x7b78/0x8110 fs/ext4/super.c:5666
       get_tree_bdev+0x3f1/0x610 fs/super.c:1366
       vfs_get_tree+0x88/0x270 fs/super.c:1573
       do_new_mount+0x24a/0xa40 fs/namespace.c:3063
       do_mount fs/namespace.c:3406 [inline]
       __do_sys_mount fs/namespace.c:3614 [inline]
       __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3591
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #1 (&dquot->dq_lock){+.+.}-{3:3}:
       __mutex_lock_common kernel/locking/mutex.c:603 [inline]
       __mutex_lock+0x120/0xaf0 kernel/locking/mutex.c:747
       dquot_commit+0x5a/0x410 fs/quota/dquot.c:507
       ext4_write_dquot+0x1f0/0x360 fs/ext4/super.c:6790
       mark_dquot_dirty fs/quota/dquot.c:372 [inline]
       mark_all_dquot_dirty+0xf9/0x400 fs/quota/dquot.c:412
       __dquot_alloc_space+0x5fc/0xe60 fs/quota/dquot.c:1752
       dquot_alloc_space_nodirty include/linux/quotaops.h:300 [inline]
       dquot_alloc_space include/linux/quotaops.h:313 [inline]
       dquot_alloc_block include/linux/quotaops.h:337 [inline]
       ext4_mb_new_blocks+0xf74/0x4720 fs/ext4/mballoc.c:5727
       ext4_alloc_branch fs/ext4/indirect.c:340 [inline]
       ext4_ind_map_blocks+0xe55/0x2220 fs/ext4/indirect.c:635
       ext4_map_blocks+0x970/0x1b60 fs/ext4/inode.c:681
       ext4_getblk+0x1ab/0x6d0 fs/ext4/inode.c:890
       ext4_bread+0x26/0x170 fs/ext4/inode.c:946
       ext4_append+0x2c3/0x560 fs/ext4/namei.c:83
       ext4_init_new_dir+0x2b8/0x570 fs/ext4/namei.c:3030
       ext4_mkdir+0x47d/0xc50 fs/ext4/namei.c:3076
       vfs_mkdir+0x387/0x570 fs/namei.c:4106
       ovl_do_mkdir fs/overlayfs/overlayfs.h:186 [inline]
       ovl_mkdir_real+0xc2/0x2a0 fs/overlayfs/dir.c:146
       ovl_workdir_create+0x330/0x7a0 fs/overlayfs/super.c:799
       ovl_get_indexdir+0x210/0x5e0 fs/overlayfs/super.c:1571
       ovl_fill_super+0x1b76/0x2ae0 fs/overlayfs/super.c:2120
       mount_nodev+0x52/0xe0 fs/super.c:1489
       legacy_get_tree+0xe6/0x180 fs/fs_context.c:632
       vfs_get_tree+0x88/0x270 fs/super.c:1573
       do_new_mount+0x24a/0xa40 fs/namespace.c:3063
       do_mount fs/namespace.c:3406 [inline]
       __do_sys_mount fs/namespace.c:3614 [inline]
       __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3591
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #0 (&ei->i_data_sem/2){++++}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3090 [inline]
       check_prevs_add kernel/locking/lockdep.c:3209 [inline]
       validate_chain kernel/locking/lockdep.c:3825 [inline]
       __lock_acquire+0x2cf8/0x7c50 kernel/locking/lockdep.c:5049
       lock_acquire+0x1b4/0x490 kernel/locking/lockdep.c:5662
       down_read+0x42/0x2d0 kernel/locking/rwsem.c:1520
       ext4_map_blocks+0x316/0x1b60 fs/ext4/inode.c:604
       ext4_getblk+0x1ab/0x6d0 fs/ext4/inode.c:890
       ext4_bread+0x26/0x170 fs/ext4/inode.c:946
       ext4_quota_write+0x230/0x570 fs/ext4/super.c:7201
       write_blk fs/quota/quota_tree.c:70 [inline]
       get_free_dqblk+0x312/0x660 fs/quota/quota_tree.c:136
       do_insert_tree+0x22b/0x1040 fs/quota/quota_tree.c:347
       do_insert_tree+0x9eb/0x1040 fs/quota/quota_tree.c:402
       do_insert_tree+0x9ae/0x1040 fs/quota/quota_tree.c:402
       do_insert_tree+0x9ae/0x1040 fs/quota/quota_tree.c:402
       dq_insert_tree fs/quota/quota_tree.c:432 [inline]
       qtree_write_dquot+0x48d/0x5b0 fs/quota/quota_tree.c:451
       v2_write_dquot+0x108/0x190 fs/quota/quota_v2.c:361
       dquot_acquire+0x2d5/0x520 fs/quota/dquot.c:472
       ext4_acquire_dquot+0x2d9/0x4a0 fs/ext4/super.c:6810
       dqget+0x778/0xeb0 fs/quota/dquot.c:988
       dquot_transfer+0x391/0x820 fs/quota/dquot.c:2150
       ext4_setattr+0x93d/0x19f0 fs/ext4/inode.c:5502
       notify_change+0xc74/0xf40 fs/attr.c:499
       chown_common+0x486/0x620 fs/open.c:736
       do_fchownat+0x164/0x270 fs/open.c:767
       __do_sys_lchown fs/open.c:792 [inline]
       __se_sys_lchown fs/open.c:790 [inline]
       __x64_sys_lchown+0x81/0x90 fs/open.c:790
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

other info that might help us debug this:

Chain exists of:
  &ei->i_data_sem/2 --> &dquot->dq_lock --> &s->s_dquot.dqio_sem

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&s->s_dquot.dqio_sem);
                               lock(&dquot->dq_lock);
                               lock(&s->s_dquot.dqio_sem);
  lock(&ei->i_data_sem/2);

 *** DEADLOCK ***

5 locks held by syz.5.1009/7019:
 #0: ffff88802426a460 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:393
 #1: ffff888072a9ca38 (&sb->s_type->i_mutex_key#8){++++}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
 #1: ffff888072a9ca38 (&sb->s_type->i_mutex_key#8){++++}-{3:3}, at: chown_common+0x320/0x620 fs/open.c:726
 #2: ffff888072a9c700 (&ei->xattr_sem){++++}-{3:3}, at: ext4_setattr+0x92a/0x19f0 fs/ext4/inode.c:5501
 #3: ffff888072bc85e8 (&dquot->dq_lock){+.+.}-{3:3}, at: dquot_acquire+0x63/0x520 fs/quota/dquot.c:460
 #4: ffff88802426a208 (&s->s_dquot.dqio_sem){++++}-{3:3}, at: v2_write_dquot+0x12b/0x190 fs/quota/quota_v2.c:357

stack backtrace:
CPU: 0 PID: 7019 Comm: syz.5.1009 Not tainted 6.1.147-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106
 check_noncircular+0x274/0x310 kernel/locking/lockdep.c:2170
 check_prev_add kernel/locking/lockdep.c:3090 [inline]
 check_prevs_add kernel/locking/lockdep.c:3209 [inline]
 validate_chain kernel/locking/lockdep.c:3825 [inline]
 __lock_acquire+0x2cf8/0x7c50 kernel/locking/lockdep.c:5049
 lock_acquire+0x1b4/0x490 kernel/locking/lockdep.c:5662
 down_read+0x42/0x2d0 kernel/locking/rwsem.c:1520
 ext4_map_blocks+0x316/0x1b60 fs/ext4/inode.c:604
 ext4_getblk+0x1ab/0x6d0 fs/ext4/inode.c:890
 ext4_bread+0x26/0x170 fs/ext4/inode.c:946
 ext4_quota_write+0x230/0x570 fs/ext4/super.c:7201
 write_blk fs/quota/quota_tree.c:70 [inline]
 get_free_dqblk+0x312/0x660 fs/quota/quota_tree.c:136
 do_insert_tree+0x22b/0x1040 fs/quota/quota_tree.c:347
 do_insert_tree+0x9eb/0x1040 fs/quota/quota_tree.c:402
 do_insert_tree+0x9ae/0x1040 fs/quota/quota_tree.c:402
 do_insert_tree+0x9ae/0x1040 fs/quota/quota_tree.c:402
 dq_insert_tree fs/quota/quota_tree.c:432 [inline]
 qtree_write_dquot+0x48d/0x5b0 fs/quota/quota_tree.c:451
 v2_write_dquot+0x108/0x190 fs/quota/quota_v2.c:361
 dquot_acquire+0x2d5/0x520 fs/quota/dquot.c:472
 ext4_acquire_dquot+0x2d9/0x4a0 fs/ext4/super.c:6810
 dqget+0x778/0xeb0 fs/quota/dquot.c:988
 dquot_transfer+0x391/0x820 fs/quota/dquot.c:2150
 ext4_setattr+0x93d/0x19f0 fs/ext4/inode.c:5502
 notify_change+0xc74/0xf40 fs/attr.c:499
 chown_common+0x486/0x620 fs/open.c:736
 do_fchownat+0x164/0x270 fs/open.c:767
 __do_sys_lchown fs/open.c:792 [inline]
 __se_sys_lchown fs/open.c:790 [inline]
 __x64_sys_lchown+0x81/0x90 fs/open.c:790
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f1345b8ebe9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f1346930038 EFLAGS: 00000246 ORIG_RAX: 000000000000005e
RAX: ffffffffffffffda RBX: 00007f1345db5fa0 RCX: 00007f1345b8ebe9
RDX: ffffffffffffffff RSI: 000000000000ee01 RDI: 0000200000000080
RBP: 00007f1345c11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1345db6038 R14: 00007f1345db5fa0 R15: 00007ffd00f51368
 </TASK>