syzbot

loop0: detected capacity change from 0 to 512
ext4 filesystem being mounted at /root/syzkaller.j5JvD9/171/file2 supports timestamps until 2038 (0x7fffffff)
======================================================
WARNING: possible circular locking dependency detected
5.15.141-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor233/3862 is trying to acquire lock:
ffff888074927ae8 (&dquot->dq_lock){+.+.}-{3:3}, at: dquot_commit+0x57/0x510 fs/quota/dquot.c:505

but task is already holding lock:
ffff8880709a8c70 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_map_blocks+0x9e0/0x1e00 fs/ext4/inode.c:638

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+0x1db/0x4f0 kernel/locking/lockdep.c:5623
       down_read+0x45/0x2e0 kernel/locking/rwsem.c:1488
       ext4_map_blocks+0x3a6/0x1e00 fs/ext4/inode.c:568
       ext4_getblk+0x19f/0x710 fs/ext4/inode.c:846
       ext4_bread+0x2a/0x170 fs/ext4/inode.c:899
       ext4_quota_write+0x21e/0x580 fs/ext4/super.c:6546
       write_blk fs/quota/quota_tree.c:64 [inline]
       get_free_dqblk+0x3a9/0x800 fs/quota/quota_tree.c:125
       do_insert_tree+0x2b4/0x1c20 fs/quota/quota_tree.c:335
       do_insert_tree+0x6d0/0x1c20 fs/quota/quota_tree.c:366
       do_insert_tree+0x6d0/0x1c20 fs/quota/quota_tree.c:366
       do_insert_tree+0x6d0/0x1c20 fs/quota/quota_tree.c:366
       dq_insert_tree fs/quota/quota_tree.c:392 [inline]
       qtree_write_dquot+0x3b9/0x530 fs/quota/quota_tree.c:411
       v2_write_dquot+0x11c/0x190 fs/quota/quota_v2.c:358
       dquot_acquire+0x34d/0x680 fs/quota/dquot.c:470
       ext4_acquire_dquot+0x2e6/0x400 fs/ext4/super.c:6180
       dqget+0x74e/0xe30 fs/quota/dquot.c:984
       __dquot_initialize+0x2d9/0xe10 fs/quota/dquot.c:1562
       ext4_mkdir+0x197/0xce0 fs/ext4/namei.c:3010
       vfs_mkdir+0x419/0x640 fs/namei.c:3994
       do_mkdirat+0x260/0x520 fs/namei.c:4019
       __do_sys_mkdir fs/namei.c:4039 [inline]
       __se_sys_mkdir fs/namei.c:4037 [inline]
       __x64_sys_mkdir+0x6a/0x80 fs/namei.c:4037
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x61/0xcb

-> #1 (&s->s_dquot.dqio_sem){++++}-{3:3}:
       lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
       down_read+0x45/0x2e0 kernel/locking/rwsem.c:1488
       v2_read_dquot+0x4a/0x100 fs/quota/quota_v2.c:332
       dquot_acquire+0x188/0x680 fs/quota/dquot.c:461
       ext4_acquire_dquot+0x2e6/0x400 fs/ext4/super.c:6180
       dqget+0x74e/0xe30 fs/quota/dquot.c:984
       __dquot_initialize+0x2d9/0xe10 fs/quota/dquot.c:1562
       ext4_process_orphan+0x57/0x2d0 fs/ext4/orphan.c:329
       ext4_orphan_cleanup+0x9d9/0x1240 fs/ext4/orphan.c:474
       ext4_fill_super+0x98de/0xa110 fs/ext4/super.c:4966
       mount_bdev+0x2c9/0x3f0 fs/super.c:1387
       legacy_get_tree+0xeb/0x180 fs/fs_context.c:611
       vfs_get_tree+0x88/0x270 fs/super.c:1517
       do_new_mount+0x28b/0xae0 fs/namespace.c:2994
       do_mount fs/namespace.c:3337 [inline]
       __do_sys_mount fs/namespace.c:3545 [inline]
       __se_sys_mount+0x2d5/0x3c0 fs/namespace.c:3522
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x61/0xcb

-> #0 (&dquot->dq_lock){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3053 [inline]
       check_prevs_add kernel/locking/lockdep.c:3172 [inline]
       validate_chain+0x1649/0x5930 kernel/locking/lockdep.c:3788
       __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012
       lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
       __mutex_lock_common+0x1da/0x25a0 kernel/locking/mutex.c:596
       __mutex_lock kernel/locking/mutex.c:729 [inline]
       mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
       dquot_commit+0x57/0x510 fs/quota/dquot.c:505
       ext4_write_dquot+0x1e8/0x2b0 fs/ext4/super.c:6164
       mark_dquot_dirty fs/quota/dquot.c:372 [inline]
       mark_all_dquot_dirty fs/quota/dquot.c:410 [inline]
       __dquot_alloc_space+0x53a/0xf30 fs/quota/dquot.c:1792
       dquot_alloc_space_nodirty include/linux/quotaops.h:297 [inline]
       dquot_alloc_space include/linux/quotaops.h:310 [inline]
       dquot_alloc_block include/linux/quotaops.h:334 [inline]
       ext4_mb_new_blocks+0x12bb/0x4d50 fs/ext4/mballoc.c:5640
       ext4_ext_map_blocks+0x1986/0x7220 fs/ext4/extents.c:4287
       ext4_map_blocks+0xaad/0x1e00 fs/ext4/inode.c:645
       ext4_getblk+0x19f/0x710 fs/ext4/inode.c:846
       ext4_bread+0x2a/0x170 fs/ext4/inode.c:899
       ext4_append+0x31f/0x5c0 fs/ext4/namei.c:83
       ext4_init_new_dir+0x33a/0xa20 fs/ext4/namei.c:2981
       ext4_mkdir+0x4f2/0xce0 fs/ext4/namei.c:3027
       vfs_mkdir+0x419/0x640 fs/namei.c:3994
       do_mkdirat+0x260/0x520 fs/namei.c:4019
       __do_sys_mkdir fs/namei.c:4039 [inline]
       __se_sys_mkdir fs/namei.c:4037 [inline]
       __x64_sys_mkdir+0x6a/0x80 fs/namei.c:4037
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x61/0xcb

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 ***

4 locks held by syz-executor233/3862:
 #0: ffff88814adea460 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x3b/0x80 fs/namespace.c:377
 #1: ffff8880709aa1d8 (&type->i_mutex_dir_key#4/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:822 [inline]
 #1: ffff8880709aa1d8 (&type->i_mutex_dir_key#4/1){+.+.}-{3:3}, at: filename_create+0x256/0x530 fs/namei.c:3765
 #2: ffff8880709a8c70 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_map_blocks+0x9e0/0x1e00 fs/ext4/inode.c:638
 #3: ffffffff8ca428d8 (dquot_srcu){....}-{0:0}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:268

stack backtrace:
CPU: 1 PID: 3862 Comm: syz-executor233 Not tainted 5.15.141-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 check_noncircular+0x2f8/0x3b0 kernel/locking/lockdep.c:2133
 check_prev_add kernel/locking/lockdep.c:3053 [inline]
 check_prevs_add kernel/locking/lockdep.c:3172 [inline]
 validate_chain+0x1649/0x5930 kernel/locking/lockdep.c:3788
 __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012
 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
 __mutex_lock_common+0x1da/0x25a0 kernel/locking/mutex.c:596
 __mutex_lock kernel/locking/mutex.c:729 [inline]
 mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
 dquot_commit+0x57/0x510 fs/quota/dquot.c:505
 ext4_write_dquot+0x1e8/0x2b0 fs/ext4/super.c:6164
 mark_dquot_dirty fs/quota/dquot.c:372 [inline]
 mark_all_dquot_dirty fs/quota/dquot.c:410 [inline]
 __dquot_alloc_space+0x53a/0xf30 fs/quota/dquot.c:1792
 dquot_alloc_space_nodirty include/linux/quotaops.h:297 [inline]
 dquot_alloc_space include/linux/quotaops.h:310 [inline]
 dquot_alloc_block include/linux/quotaops.h:334 [inline]
 ext4_mb_new_blocks+0x12bb/0x4d50 fs/ext4/mballoc.c:5640
 ext4_ext_map_blocks+0x1986/0x7220 fs/ext4/extents.c:4287
 ext4_map_blocks+0xaad/0x1e00 fs/ext4/inode.c:645
 ext4_getblk+0x19f/0x710 fs/ext4/inode.c:846
 ext4_bread+0x2a/0x170 fs/ext4/inode.c:899
 ext4_append+0x31f/0x5c0 fs/ext4/namei.c:83
 ext4_init_new_dir+0x33a/0xa20 fs/ext4/namei.c:2981
 ext4_mkdir+0x4f2/0xce0 fs/ext4/namei.c:3027
 vfs_mkdir+0x419/0x640 fs/namei.c:3994
 do_mkdirat+0x260/0x520 fs/namei.c:4019
 __do_sys_mkdir fs/namei.c:4039 [inline]
 __se_sys_mkdir fs/namei.c:4037 [inline]
 __x64_sys_mkdir+0x6a/0x80 fs/namei.c:4037
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7fd063af01a7
Code: 73 01 c3 48 c7 c1 b8 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 53 00 00 00 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:00007ffc43d5ca08 EFLAGS: 00000286 ORIG_RAX: 0000000000000053
RAX: ffffffffffffffda RBX: 00000000ffffffff RCX: 00007fd063af01a7
RDX: 0000000000000040 RSI: 00000000000001ff RDI: 0000000020000540
RBP: 00007ffc43d5caa0 R08: 00000000000000fd R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000286 R12: 0000000020000540
R13: 00000000200000c0 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
EXT4-fs error (device loop0): ext4_do_update_inode:5160: inode #2: comm syz-executor233: corrupted inode contents
EXT4-fs error (device loop0): ext4_dirty_inode:5993: inode #2: comm syz-executor233: mark_inode_dirty error
EXT4-fs error (device loop0): ext4_do_update_inode:5160: inode #2: comm syz-executor233: corrupted inode contents
EXT4-fs error (device loop0): __ext4_ext_dirty:183: inode #2: comm syz-executor233: mark_inode_dirty error