loop0: detected capacity change from 1024 to 0
EXT4-fs error (device loop0): ext4_mb_generate_buddy:802: group 0, block bitmap and bg descriptor inconsistent: 7554 vs 23 free clusters
======================================================
WARNING: possible circular locking dependency detected
5.11.0-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.0/9296 is trying to acquire lock:
ffff888034cc4428 (&dquot->dq_lock){+.+.}-{3:3}, at: dquot_commit+0x48/0x390 fs/quota/dquot.c:476

but task is already holding lock:
ffff88802f33c878 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_truncate+0x4bb/0x10c0 fs/ext4/inode.c:4258

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (&ei->i_data_sem/2){++++}-{3:3}:
       down_read+0x95/0x440 kernel/locking/rwsem.c:1353
       ext4_map_blocks+0x2d1/0x1340 fs/ext4/inode.c:560
       ext4_getblk+0x111/0x550 fs/ext4/inode.c:847
       ext4_bread+0x8/0x160 fs/ext4/inode.c:899
       ext4_quota_write+0x21d/0x590 fs/ext4/super.c:6557
       write_blk+0x108/0x1e0 fs/quota/quota_tree.c:73
       get_free_dqblk+0xe4/0x270 fs/quota/quota_tree.c:102
       do_insert_tree+0x460/0xed0 fs/quota/quota_tree.c:309
       do_insert_tree+0xc28/0xed0 fs/quota/quota_tree.c:340
       do_insert_tree+0x4f0/0xed0 fs/quota/quota_tree.c:340
       dq_insert_tree fs/quota/quota_tree.c:366 [inline]
       qtree_write_dquot+0x360/0x4f0 fs/quota/quota_tree.c:385
       v2_write_dquot+0x105/0x230 fs/quota/quota_v2.c:353
       dquot_acquire+0x25b/0x500 fs/quota/dquot.c:443
       ext4_acquire_dquot+0x23c/0x360 fs/ext4/super.c:6216
       dqget+0x55a/0xeb0 fs/quota/dquot.c:901
       __dquot_initialize+0x416/0x1060 fs/quota/dquot.c:1479
       ext4_orphan_cleanup fs/ext4/super.c:3077 [inline]
       ext4_fill_super+0x7467/0xbc40 fs/ext4/super.c:5049
       mount_bdev+0x2cb/0x3b0 fs/super.c:1366
       legacy_get_tree+0xfa/0x1f0 fs/fs_context.c:592
       vfs_get_tree+0x7f/0x2c0 fs/super.c:1496
       do_new_mount fs/namespace.c:2881 [inline]
       path_mount+0x7f3/0x1b30 fs/namespace.c:3211
       do_mount fs/namespace.c:3224 [inline]
       __do_sys_mount fs/namespace.c:3432 [inline]
       __se_sys_mount fs/namespace.c:3409 [inline]
       __x64_sys_mount+0x1f5/0x260 fs/namespace.c:3409
       do_syscall_64+0x2d/0x40 arch/x86/entry/common.c:46
       entry_SYSCALL_64_after_hwframe+0x44/0xa9

-> #1 (&s->s_dquot.dqio_sem){++++}-{3:3}:
       down_read+0x95/0x440 kernel/locking/rwsem.c:1353
       v2_read_dquot+0x44/0x110 fs/quota/quota_v2.c:327
       dquot_acquire+0x111/0x500 fs/quota/dquot.c:434
       ext4_acquire_dquot+0x23c/0x360 fs/ext4/super.c:6216
       dqget+0x55a/0xeb0 fs/quota/dquot.c:901
       __dquot_initialize+0x416/0x1060 fs/quota/dquot.c:1479
       ext4_orphan_cleanup fs/ext4/super.c:3077 [inline]
       ext4_fill_super+0x7467/0xbc40 fs/ext4/super.c:5049
       mount_bdev+0x2cb/0x3b0 fs/super.c:1366
       legacy_get_tree+0xfa/0x1f0 fs/fs_context.c:592
       vfs_get_tree+0x7f/0x2c0 fs/super.c:1496
       do_new_mount fs/namespace.c:2881 [inline]
       path_mount+0x7f3/0x1b30 fs/namespace.c:3211
       do_mount fs/namespace.c:3224 [inline]
       __do_sys_mount fs/namespace.c:3432 [inline]
       __se_sys_mount fs/namespace.c:3409 [inline]
       __x64_sys_mount+0x1f5/0x260 fs/namespace.c:3409
       do_syscall_64+0x2d/0x40 arch/x86/entry/common.c:46
       entry_SYSCALL_64_after_hwframe+0x44/0xa9

-> #0 (&dquot->dq_lock){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:2868 [inline]
       check_prevs_add kernel/locking/lockdep.c:2993 [inline]
       validate_chain kernel/locking/lockdep.c:3608 [inline]
       __lock_acquire+0x2b2a/0x5500 kernel/locking/lockdep.c:4832
       lock_acquire kernel/locking/lockdep.c:5442 [inline]
       lock_acquire+0x1a8/0x720 kernel/locking/lockdep.c:5407
       __mutex_lock_common kernel/locking/mutex.c:956 [inline]
       __mutex_lock+0x134/0x1110 kernel/locking/mutex.c:1103
       dquot_commit+0x48/0x390 fs/quota/dquot.c:476
       ext4_write_dquot+0x201/0x2d0 fs/ext4/super.c:6200
       mark_dquot_dirty fs/quota/dquot.c:347 [inline]
       mark_all_dquot_dirty fs/quota/dquot.c:385 [inline]
       __dquot_free_space+0x5fb/0x910 fs/quota/dquot.c:1894
       dquot_free_space_nodirty include/linux/quotaops.h:376 [inline]
       dquot_free_space include/linux/quotaops.h:381 [inline]
       dquot_free_block include/linux/quotaops.h:392 [inline]
       ext4_free_blocks+0x952/0x16f0 fs/ext4/mballoc.c:5472
       ext4_remove_blocks fs/ext4/extents.c:2480 [inline]
       ext4_ext_rm_leaf fs/ext4/extents.c:2664 [inline]
       ext4_ext_remove_space+0x2b4c/0x3fe0 fs/ext4/extents.c:2912
       ext4_ext_truncate+0x19e/0x210 fs/ext4/extents.c:4370
       ext4_truncate+0x7fe/0x10c0 fs/ext4/inode.c:4263
       ext4_evict_inode+0x7fe/0x1560 fs/ext4/inode.c:287
       evict+0x296/0x5d0 fs/inode.c:577
       __dentry_kill+0x315/0x550 fs/dcache.c:579
       dentry_kill fs/dcache.c:705 [inline]
       dput+0x410/0x880 fs/dcache.c:885
       do_renameat2+0x534/0x980 fs/namei.c:4461
       __do_sys_renameat2 fs/namei.c:4495 [inline]
       __se_sys_renameat2 fs/namei.c:4492 [inline]
       __x64_sys_renameat2+0xdf/0x120 fs/namei.c:4492
       do_syscall_64+0x2d/0x40 arch/x86/entry/common.c:46
       entry_SYSCALL_64_after_hwframe+0x44/0xa9

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-executor.0/9296:
 #0: ffff88802a0a2460 (sb_writers#5){.+.+}-{0:0}, at: do_renameat2+0x2ae/0x980 fs/namei.c:4402
 #1: ffff88802f338e88 (&type->i_mutex_dir_key#4/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:808 [inline]
 #1: ffff88802f338e88 (&type->i_mutex_dir_key#4/1){+.+.}-{3:3}, at: lock_rename+0x1de/0x230 fs/namei.c:2758
 #2: ffff88802a0a2650 (sb_internal){.+.+}-{0:0}, at: evict+0x296/0x5d0 fs/inode.c:577
 #3: ffff88802f33c878 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_truncate+0x4bb/0x10c0 fs/ext4/inode.c:4258
 #4: ffffffff8a90a238 (dquot_srcu){....}-{0:0}, at: i_dquot fs/quota/dquot.c:926 [inline]
 #4: ffffffff8a90a238 (dquot_srcu){....}-{0:0}, at: __dquot_free_space+0x163/0x910 fs/quota/dquot.c:1867

stack backtrace:
CPU: 0 PID: 9296 Comm: syz-executor.0 Not tainted 5.11.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x9a/0xcc lib/dump_stack.c:120
 check_noncircular+0x25f/0x2e0 kernel/locking/lockdep.c:2117
 check_prev_add kernel/locking/lockdep.c:2868 [inline]
 check_prevs_add kernel/locking/lockdep.c:2993 [inline]
 validate_chain kernel/locking/lockdep.c:3608 [inline]
 __lock_acquire+0x2b2a/0x5500 kernel/locking/lockdep.c:4832
 lock_acquire kernel/locking/lockdep.c:5442 [inline]
 lock_acquire+0x1a8/0x720 kernel/locking/lockdep.c:5407
 __mutex_lock_common kernel/locking/mutex.c:956 [inline]
 __mutex_lock+0x134/0x1110 kernel/locking/mutex.c:1103
 dquot_commit+0x48/0x390 fs/quota/dquot.c:476
 ext4_write_dquot+0x201/0x2d0 fs/ext4/super.c:6200
 mark_dquot_dirty fs/quota/dquot.c:347 [inline]
 mark_all_dquot_dirty fs/quota/dquot.c:385 [inline]
 __dquot_free_space+0x5fb/0x910 fs/quota/dquot.c:1894
 dquot_free_space_nodirty include/linux/quotaops.h:376 [inline]
 dquot_free_space include/linux/quotaops.h:381 [inline]
 dquot_free_block include/linux/quotaops.h:392 [inline]
 ext4_free_blocks+0x952/0x16f0 fs/ext4/mballoc.c:5472
 ext4_remove_blocks fs/ext4/extents.c:2480 [inline]
 ext4_ext_rm_leaf fs/ext4/extents.c:2664 [inline]
 ext4_ext_remove_space+0x2b4c/0x3fe0 fs/ext4/extents.c:2912
 ext4_ext_truncate+0x19e/0x210 fs/ext4/extents.c:4370
 ext4_truncate+0x7fe/0x10c0 fs/ext4/inode.c:4263
 ext4_evict_inode+0x7fe/0x1560 fs/ext4/inode.c:287
 evict+0x296/0x5d0 fs/inode.c:577
 __dentry_kill+0x315/0x550 fs/dcache.c:579
 dentry_kill fs/dcache.c:705 [inline]
 dput+0x410/0x880 fs/dcache.c:885
 do_renameat2+0x534/0x980 fs/namei.c:4461
 __do_sys_renameat2 fs/namei.c:4495 [inline]
 __se_sys_renameat2 fs/namei.c:4492 [inline]
 __x64_sys_renameat2+0xdf/0x120 fs/namei.c:4492
 do_syscall_64+0x2d/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7fd663220639
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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fd662593168 EFLAGS: 00000246 ORIG_RAX: 000000000000013c
RAX: ffffffffffffffda RBX: 00007fd663340f80 RCX: 00007fd663220639
RDX: 0000000000000003 RSI: 0000000020000080 RDI: 0000000000000004
RBP: 00007fd66327bae9 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000200000c0 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffe71719d1f R14: 00007fd662593300 R15: 0000000000022000
EXT4-fs error (device loop0): ext4_free_inode:351: comm syz-executor.0: bit already cleared for inode 13