EXT4-fs error (device loop4): ext4_mb_generate_buddy:1102: group 0, block bitmap and bg descriptor inconsistent: 41 vs 39667 free clusters
======================================================
WARNING: possible circular locking dependency detected
6.1.119-syzkaller #0 Not tainted
------------------------------------------------------
syz.4.3881/18480 is trying to acquire lock:
ffff8880555f33e8 (&dquot->dq_lock){+.+.}-{3:3}, at: dquot_commit+0x57/0x510 fs/quota/dquot.c:507

but task is already holding lock:
ffff88805c890c90 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_truncate+0x999/0x1290 fs/ext4/inode.c:4283

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (&ei->i_data_sem/2){++++}-{3:3}:
       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:7171
       write_blk fs/quota/quota_tree.c:70 [inline]
       get_free_dqblk+0x340/0x6c0 fs/quota/quota_tree.c:136
       do_insert_tree+0x298/0x1440 fs/quota/quota_tree.c:347
       do_insert_tree+0xb94/0x1440 fs/quota/quota_tree.c:402
       do_insert_tree+0xb51/0x1440 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:6797
       dqget+0x762/0xe90 fs/quota/dquot.c:986
       __dquot_initialize+0x45e/0xea0 fs/quota/dquot.c:1515
       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

-> #1 (&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:6797
       dqget+0x762/0xe90 fs/quota/dquot.c:986
       __dquot_initialize+0x2d9/0xea0 fs/quota/dquot.c:1515
       __ext4_new_inode+0x89e/0x43a0 fs/ext4/ialloc.c:995
       ext4_ext_migrate+0x679/0x12f0 fs/ext4/migrate.c:455
       ext4_ioctl_setflags fs/ext4/ioctl.c:695 [inline]
       ext4_fileattr_set+0xf06/0x1770 fs/ext4/ioctl.c:1008
       vfs_fileattr_set+0x8f3/0xd30 fs/ioctl.c:696
       ioctl_setflags fs/ioctl.c:728 [inline]
       do_vfs_ioctl+0x1cd1/0x2a90 fs/ioctl.c:839
       __do_sys_ioctl fs/ioctl.c:868 [inline]
       __se_sys_ioctl+0x81/0x160 fs/ioctl.c:856
       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 (&dquot->dq_lock){+.+.}-{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
       __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:6777
       mark_dquot_dirty fs/quota/dquot.c:372 [inline]
       mark_all_dquot_dirty+0xf7/0x400 fs/quota/dquot.c:412
       __dquot_free_space+0x956/0xe70 fs/quota/dquot.c:1940
       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+0x22bb/0x4f30 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:701
       __dentry_kill+0x436/0x650 fs/dcache.c:611
       dentry_kill+0xbb/0x290
       dput+0xfb/0x1d0 fs/dcache.c:918
       do_renameat2+0xded/0x1440 fs/namei.c:5029
       __do_sys_renameat fs/namei.c:5067 [inline]
       __se_sys_renameat fs/namei.c:5064 [inline]
       __x64_sys_renameat+0xb8/0xd0 fs/namei.c:5064
       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:
  &dquot->dq_lock --> &s->s_dquot.dqio_sem --> &ei->i_data_sem/2

 Possible unsafe locking scenario:

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

 *** DEADLOCK ***

5 locks held by syz.4.3881/18480:
 #0: ffff888027f4e460 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x3b/0x80 fs/namespace.c:393
 #1: ffff88807431de48 (&type->i_mutex_dir_key#3/1){+.+.}-{3:3}, at: do_renameat2+0x65a/0x1440 fs/namei.c:4966
 #2: ffff888027f4e650 (sb_internal){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1891 [inline]
 #2: ffff888027f4e650 (sb_internal){.+.+}-{0:0}, at: sb_start_intwrite include/linux/fs.h:2013 [inline]
 #2: ffff888027f4e650 (sb_internal){.+.+}-{0:0}, at: ext4_evict_inode+0x46d/0x1150 fs/ext4/inode.c:240
 #3: ffff88805c890c90 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_truncate+0x999/0x1290 fs/ext4/inode.c:4283
 #4: ffffffff8d472828 (dquot_srcu){....}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 #4: ffffffff8d472828 (dquot_srcu){....}-{0:0}, at: srcu_read_lock include/linux/srcu.h:165 [inline]
 #4: ffffffff8d472828 (dquot_srcu){....}-{0:0}, at: __dquot_free_space+0x1da/0xe70 fs/quota/dquot.c:1913

stack backtrace:
CPU: 1 PID: 18480 Comm: syz.4.3881 Not tainted 6.1.119-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024
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
 __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:6777
 mark_dquot_dirty fs/quota/dquot.c:372 [inline]
 mark_all_dquot_dirty+0xf7/0x400 fs/quota/dquot.c:412
 __dquot_free_space+0x956/0xe70 fs/quota/dquot.c:1940
 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+0x22bb/0x4f30 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:701
 __dentry_kill+0x436/0x650 fs/dcache.c:611
 dentry_kill+0xbb/0x290
 dput+0xfb/0x1d0 fs/dcache.c:918
 do_renameat2+0xded/0x1440 fs/namei.c:5029
 __do_sys_renameat fs/namei.c:5067 [inline]
 __se_sys_renameat fs/namei.c:5064 [inline]
 __x64_sys_renameat+0xb8/0xd0 fs/namei.c:5064
 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: 0033:0x7ff683b7e819
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:00007ff6848cf038 EFLAGS: 00000246 ORIG_RAX: 0000000000000108
RAX: ffffffffffffffda RBX: 00007ff683d35fa0 RCX: 00007ff683b7e819
RDX: 0000000000000004 RSI: 0000000020000400 RDI: 0000000000000004
RBP: 00007ff683bf175e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000020000440 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007ff683d35fa0 R15: 00007fff13eee868
 </TASK>