ext4 filesystem being mounted at /94/file0 supports timestamps until 2038-01-19 (0x7fffffff)
======================================================
WARNING: possible circular locking dependency detected
6.1.131-syzkaller #0 Not tainted
------------------------------------------------------
syz.6.1160/8680 is trying to acquire lock:
ffff8880515c20a0 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_map_blocks+0x955/0x1cb0 fs/ext4/inode.c:671

but task is already holding lock:
ffff88807cde0208 (&s->s_dquot.dqio_sem){++++}-{3:3}, at: v2_write_dquot+0x9b/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}:
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
       down_read+0xad/0xa30 kernel/locking/rwsem.c:1520
       v2_read_dquot+0x4a/0x100 fs/quota/quota_v2.c:335
       dquot_acquire+0x188/0x680 fs/quota/dquot.c:463
       ext4_acquire_dquot+0x2eb/0x4a0 fs/ext4/super.c:6791
       dqget+0x762/0xe90 fs/quota/dquot.c:988
       __dquot_initialize+0x45e/0xea0 fs/quota/dquot.c:1517
       ext4_process_orphan+0x57/0x2d0 fs/ext4/orphan.c:329
       ext4_orphan_cleanup+0xb70/0x1400 fs/ext4/orphan.c:474
       __ext4_fill_super fs/ext4/super.c:5523 [inline]
       ext4_fill_super+0x84b2/0x89e0 fs/ext4/super.c:5654
       get_tree_bdev+0x3fe/0x620 fs/super.c:1366
       vfs_get_tree+0x88/0x270 fs/super.c:1573
       do_new_mount+0x2ba/0xb40 fs/namespace.c:3056
       do_mount fs/namespace.c:3399 [inline]
       __do_sys_mount fs/namespace.c:3607 [inline]
       __se_sys_mount+0x2d5/0x3c0 fs/namespace.c:3584
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #1 (&dquot->dq_lock){+.+.}-{3:3}:
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
       __mutex_lock_common kernel/locking/mutex.c:603 [inline]
       __mutex_lock+0x132/0xd80 kernel/locking/mutex.c:747
       dquot_commit+0x57/0x510 fs/quota/dquot.c:507
       ext4_write_dquot+0x1fd/0x360 fs/ext4/super.c:6771
       mark_dquot_dirty fs/quota/dquot.c:372 [inline]
       mark_all_dquot_dirty+0x1e0/0x400 fs/quota/dquot.c:412
       __dquot_free_space+0x956/0xe70 fs/quota/dquot.c:1942
       dquot_free_space_nodirty include/linux/quotaops.h:379 [inline]
       dquot_free_space include/linux/quotaops.h:384 [inline]
       dquot_free_block include/linux/quotaops.h:395 [inline]
       ext4_mb_clear_bb fs/ext4/mballoc.c:6143 [inline]
       ext4_free_blocks+0x1fb4/0x3020 fs/ext4/mballoc.c:6273
       ext4_remove_blocks fs/ext4/extents.c:2525 [inline]
       ext4_ext_rm_leaf fs/ext4/extents.c:2691 [inline]
       ext4_ext_remove_space+0x25c6/0x4f40 fs/ext4/extents.c:2939
       ext4_ext_truncate+0x201/0x360 fs/ext4/extents.c:4469
       ext4_truncate+0xa1d/0x1290 fs/ext4/inode.c:4288
       ext4_evict_inode+0xb68/0x1150 fs/ext4/inode.c:286
       evict+0x529/0x930 fs/inode.c:705
       ext4_orphan_cleanup+0xb70/0x1400 fs/ext4/orphan.c:474
       __ext4_fill_super fs/ext4/super.c:5523 [inline]
       ext4_fill_super+0x84b2/0x89e0 fs/ext4/super.c:5654
       get_tree_bdev+0x3fe/0x620 fs/super.c:1366
       vfs_get_tree+0x88/0x270 fs/super.c:1573
       do_new_mount+0x2ba/0xb40 fs/namespace.c:3056
       do_mount fs/namespace.c:3399 [inline]
       __do_sys_mount fs/namespace.c:3607 [inline]
       __se_sys_mount+0x2d5/0x3c0 fs/namespace.c:3584
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x3b/0xb0 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+0x1661/0x5950 kernel/locking/lockdep.c:3825
       __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
       down_write+0x36/0x60 kernel/locking/rwsem.c:1573
       ext4_map_blocks+0x955/0x1cb0 fs/ext4/inode.c:671
       ext4_getblk+0x1eb/0x7c0 fs/ext4/inode.c:889
       ext4_bread+0x2a/0x170 fs/ext4/inode.c:945
       ext4_quota_write+0x21e/0x570 fs/ext4/super.c:7165
       write_blk fs/quota/quota_tree.c:70 [inline]
       find_free_dqentry+0x685/0xc50 fs/quota/quota_tree.c:318
       do_insert_tree+0x8a4/0x1460 fs/quota/quota_tree.c:400
       do_insert_tree+0xb68/0x1460 fs/quota/quota_tree.c:402
       do_insert_tree+0xb68/0x1460 fs/quota/quota_tree.c:402
       do_insert_tree+0xb68/0x1460 fs/quota/quota_tree.c:402
       dq_insert_tree fs/quota/quota_tree.c:432 [inline]
       qtree_write_dquot+0x483/0x5a0 fs/quota/quota_tree.c:451
       v2_write_dquot+0x11c/0x190 fs/quota/quota_v2.c:361
       dquot_acquire+0x34d/0x680 fs/quota/dquot.c:472
       ext4_acquire_dquot+0x2eb/0x4a0 fs/ext4/super.c:6791
       dqget+0x762/0xe90 fs/quota/dquot.c:988
       __dquot_initialize+0x45e/0xea0 fs/quota/dquot.c:1517
       ext4_mkdir+0x197/0xce0 fs/ext4/namei.c:3059
       vfs_mkdir+0x3b6/0x590 fs/namei.c:4106
       do_mkdirat+0x225/0x360 fs/namei.c:4131
       __do_sys_mkdirat fs/namei.c:4146 [inline]
       __se_sys_mkdirat fs/namei.c:4144 [inline]
       __x64_sys_mkdirat+0x85/0x90 fs/namei.c:4144
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x3b/0xb0 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 ***

4 locks held by syz.6.1160/8680:
 #0: ffff88807cde0460 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x3b/0x80 fs/namespace.c:393
 #1: ffff8880515c5e48 (&type->i_mutex_dir_key#3/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:793 [inline]
 #1: ffff8880515c5e48 (&type->i_mutex_dir_key#3/1){+.+.}-{3:3}, at: filename_create+0x25c/0x530 fs/namei.c:3876
 #2: ffff8880729e3228 (&dquot->dq_lock){+.+.}-{3:3}, at: dquot_acquire+0x64/0x680 fs/quota/dquot.c:460
 #3: ffff88807cde0208 (&s->s_dquot.dqio_sem){++++}-{3:3}, at: v2_write_dquot+0x9b/0x190 fs/quota/quota_v2.c:357

stack backtrace:
CPU: 0 PID: 8680 Comm: syz.6.1160 Not tainted 6.1.131-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 check_noncircular+0x2fa/0x3b0 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+0x1661/0x5950 kernel/locking/lockdep.c:3825
 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049
 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
 down_write+0x36/0x60 kernel/locking/rwsem.c:1573
 ext4_map_blocks+0x955/0x1cb0 fs/ext4/inode.c:671
 ext4_getblk+0x1eb/0x7c0 fs/ext4/inode.c:889
 ext4_bread+0x2a/0x170 fs/ext4/inode.c:945
 ext4_quota_write+0x21e/0x570 fs/ext4/super.c:7165
 write_blk fs/quota/quota_tree.c:70 [inline]
 find_free_dqentry+0x685/0xc50 fs/quota/quota_tree.c:318
 do_insert_tree+0x8a4/0x1460 fs/quota/quota_tree.c:400
 do_insert_tree+0xb68/0x1460 fs/quota/quota_tree.c:402
 do_insert_tree+0xb68/0x1460 fs/quota/quota_tree.c:402
 do_insert_tree+0xb68/0x1460 fs/quota/quota_tree.c:402
 dq_insert_tree fs/quota/quota_tree.c:432 [inline]
 qtree_write_dquot+0x483/0x5a0 fs/quota/quota_tree.c:451
 v2_write_dquot+0x11c/0x190 fs/quota/quota_v2.c:361
 dquot_acquire+0x34d/0x680 fs/quota/dquot.c:472
 ext4_acquire_dquot+0x2eb/0x4a0 fs/ext4/super.c:6791
 dqget+0x762/0xe90 fs/quota/dquot.c:988
 __dquot_initialize+0x45e/0xea0 fs/quota/dquot.c:1517
 ext4_mkdir+0x197/0xce0 fs/ext4/namei.c:3059
 vfs_mkdir+0x3b6/0x590 fs/namei.c:4106
 do_mkdirat+0x225/0x360 fs/namei.c:4131
 __do_sys_mkdirat fs/namei.c:4146 [inline]
 __se_sys_mkdirat fs/namei.c:4144 [inline]
 __x64_sys_mkdirat+0x85/0x90 fs/namei.c:4144
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f842d18b9d7
Code: 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 02 01 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:00007f842e07be68 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f842e07bef0 RCX: 00007f842d18b9d7
RDX: 00000000000001ff RSI: 0000200000000280 RDI: 00000000ffffff9c
RBP: 00002000000002c0 R08: 00002000000007c0 R09: 0000000000000000
R10: 00002000000002c0 R11: 0000000000000246 R12: 0000200000000280
R13: 00007f842e07beb0 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
EXT4-fs error (device loop6): ext4_get_first_dir_block:3583: inode #12: comm syz.6.1160: Attempting to read directory block (0) that is past i_size (3)
EXT4-fs (loop6): Remounting filesystem read-only