syzbot

loop0: detected capacity change from 0 to 512
======================================================
WARNING: possible circular locking dependency detected
5.15.185-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor415/4368 is trying to acquire lock:
ffff88806f5a8268 (&dquot->dq_lock){+.+.}-{3:3}, at: dquot_commit+0x5a/0x410 fs/quota/dquot.c:507

but task is already holding lock:
ffff88806f57e628 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_truncate+0x96d/0x10d0 fs/ext4/inode.c:4245

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+0x44/0x2e0 kernel/locking/rwsem.c:1498
       ext4_map_blocks+0x32f/0x1b30 fs/ext4/inode.c:598
       ext4_getblk+0x16d/0x630 fs/ext4/inode.c:870
       ext4_bread+0x26/0x180 fs/ext4/inode.c:923
       ext4_quota_write+0x230/0x570 fs/ext4/super.c:6591
       write_blk fs/quota/quota_tree.c:64 [inline]
       get_free_dqblk+0x387/0x7d0 fs/quota/quota_tree.c:125
       do_insert_tree+0x214/0x1970 fs/quota/quota_tree.c:335
       do_insert_tree+0x5b1/0x1970 fs/quota/quota_tree.c:366
       do_insert_tree+0x5b1/0x1970 fs/quota/quota_tree.c:366
       do_insert_tree+0x5b1/0x1970 fs/quota/quota_tree.c:366
       dq_insert_tree fs/quota/quota_tree.c:392 [inline]
       qtree_write_dquot+0x361/0x4b0 fs/quota/quota_tree.c:411
       v2_write_dquot+0x108/0x190 fs/quota/quota_v2.c:358
       dquot_acquire+0x2d5/0x520 fs/quota/dquot.c:472
       ext4_acquire_dquot+0x2d9/0x4a0 fs/ext4/super.c:6200
       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+0xaa9/0x12e0 fs/ext4/orphan.c:474
       ext4_fill_super+0x9288/0x9a00 fs/ext4/super.c:4975
       mount_bdev+0x287/0x3c0 fs/super.c:1400
       legacy_get_tree+0xe6/0x180 fs/fs_context.c:611
       vfs_get_tree+0x88/0x270 fs/super.c:1530
       do_new_mount+0x24a/0xa40 fs/namespace.c:3010
       do_mount fs/namespace.c:3353 [inline]
       __do_sys_mount fs/namespace.c:3561 [inline]
       __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3538
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

-> #1 (&s->s_dquot.dqio_sem){++++}-{3:3}:
       down_read+0x44/0x2e0 kernel/locking/rwsem.c:1498
       v2_read_dquot+0x4a/0x110 fs/quota/quota_v2.c:332
       dquot_acquire+0x152/0x520 fs/quota/dquot.c:463
       ext4_acquire_dquot+0x2d9/0x4a0 fs/ext4/super.c:6200
       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+0xaa9/0x12e0 fs/ext4/orphan.c:474
       ext4_fill_super+0x9288/0x9a00 fs/ext4/super.c:4975
       mount_bdev+0x287/0x3c0 fs/super.c:1400
       legacy_get_tree+0xe6/0x180 fs/fs_context.c:611
       vfs_get_tree+0x88/0x270 fs/super.c:1530
       do_new_mount+0x24a/0xa40 fs/namespace.c:3010
       do_mount fs/namespace.c:3353 [inline]
       __do_sys_mount fs/namespace.c:3561 [inline]
       __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3538
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

-> #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 kernel/locking/lockdep.c:3788 [inline]
       __lock_acquire+0x2c33/0x7c60 kernel/locking/lockdep.c:5012
       lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623
       __mutex_lock_common+0x1eb/0x2390 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+0x5a/0x410 fs/quota/dquot.c:507
       ext4_write_dquot+0x1f0/0x360 fs/ext4/super.c:6180
       mark_dquot_dirty fs/quota/dquot.c:372 [inline]
       mark_all_dquot_dirty+0xf9/0x400 fs/quota/dquot.c:412
       __dquot_free_space+0x7ca/0xb90 fs/quota/dquot.c:1942
       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_mb_clear_bb fs/ext4/mballoc.c:6156 [inline]
       ext4_free_blocks+0x1af5/0x2480 fs/ext4/mballoc.c:6286
       ext4_remove_blocks fs/ext4/extents.c:2523 [inline]
       ext4_ext_rm_leaf fs/ext4/extents.c:2689 [inline]
       ext4_ext_remove_space+0x1eaa/0x4390 fs/ext4/extents.c:2937
       ext4_ext_truncate+0x192/0x240 fs/ext4/extents.c:4471
       ext4_truncate+0x9f1/0x10d0 fs/ext4/inode.c:4250
       ext4_process_orphan+0x1cb/0x300 fs/ext4/orphan.c:339
       ext4_orphan_cleanup+0xaa9/0x12e0 fs/ext4/orphan.c:474
       ext4_fill_super+0x9288/0x9a00 fs/ext4/super.c:4975
       mount_bdev+0x287/0x3c0 fs/super.c:1400
       legacy_get_tree+0xe6/0x180 fs/fs_context.c:611
       vfs_get_tree+0x88/0x270 fs/super.c:1530
       do_new_mount+0x24a/0xa40 fs/namespace.c:3010
       do_mount fs/namespace.c:3353 [inline]
       __do_sys_mount fs/namespace.c:3561 [inline]
       __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3538
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

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-executor415/4368:
 #0: ffff88807b3e60e0 (&type->s_umount_key#28/1){+.+.}-{3:3}, at: alloc_super+0x201/0x950 fs/super.c:229
 #1: ffff88806f57e7a0 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline]
 #1: ffff88806f57e7a0 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: ext4_process_orphan+0x187/0x300 fs/ext4/orphan.c:337
 #2: ffff88806f57e628 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_truncate+0x96d/0x10d0 fs/ext4/inode.c:4245
 #3: ffffffff8c23fd58 (dquot_srcu){....}-{0:0}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:311

stack backtrace:
CPU: 0 PID: 4368 Comm: syz-executor415 Not tainted 5.15.185-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
 check_noncircular+0x274/0x310 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 kernel/locking/lockdep.c:3788 [inline]
 __lock_acquire+0x2c33/0x7c60 kernel/locking/lockdep.c:5012
 lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623
 __mutex_lock_common+0x1eb/0x2390 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+0x5a/0x410 fs/quota/dquot.c:507
 ext4_write_dquot+0x1f0/0x360 fs/ext4/super.c:6180
 mark_dquot_dirty fs/quota/dquot.c:372 [inline]
 mark_all_dquot_dirty+0xf9/0x400 fs/quota/dquot.c:412
 __dquot_free_space+0x7ca/0xb90 fs/quota/dquot.c:1942
 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_mb_clear_bb fs/ext4/mballoc.c:6156 [inline]
 ext4_free_blocks+0x1af5/0x2480 fs/ext4/mballoc.c:6286
 ext4_remove_blocks fs/ext4/extents.c:2523 [inline]
 ext4_ext_rm_leaf fs/ext4/extents.c:2689 [inline]
 ext4_ext_remove_space+0x1eaa/0x4390 fs/ext4/extents.c:2937
 ext4_ext_truncate+0x192/0x240 fs/ext4/extents.c:4471
 ext4_truncate+0x9f1/0x10d0 fs/ext4/inode.c:4250
 ext4_process_orphan+0x1cb/0x300 fs/ext4/orphan.c:339
 ext4_orphan_cleanup+0xaa9/0x12e0 fs/ext4/orphan.c:474
 ext4_fill_super+0x9288/0x9a00 fs/ext4/super.c:4975
 mount_bdev+0x287/0x3c0 fs/super.c:1400
 legacy_get_tree+0xe6/0x180 fs/fs_context.c:611
 vfs_get_tree+0x88/0x270 fs/super.c:1530
 do_new_mount+0x24a/0xa40 fs/namespace.c:3010
 do_mount fs/namespace.c:3353 [inline]
 __do_sys_mount fs/namespace.c:3561 [inline]
 __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3538
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7ffbbe59676a
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 5e 04 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 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:00007ffec6ae25b8 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ffec6ae2610 RCX: 00007ffbbe59676a
RDX: 00002000000000c0 RSI: 0000200000000640 RDI: 00007ffec6ae2610
RBP: 0000200000000640 R08: 00007ffec6ae2650 R09: 0000000000000515
R10: 0000000003000010 R11: 0000000000000206 R12: 00002000000000c0
R13: 00007ffec6ae2650 R14: 000000000000051b R15: 0000200000000000
 </TASK>
EXT4-fs error (device loop0): ext4_do_update_inode:5203: inode #16: comm syz-executor415: corrupted inode contents
EXT4-fs error (device loop0): ext4_dirty_inode:6039: inode #16: comm syz-executor415: mark_inode_dirty error
EXT4-fs error (device loop0): ext4_do_update_inode:5203: inode #16: comm syz-executor415: corrupted inode contents
EXT4-fs error (device loop0): __ext4_ext_dirty:183: inode #16: comm syz-executor415: mark_inode_dirty error
EXT4-fs error (device loop0): ext4_do_update_inode:5203: inode #16: comm syz-executor415: corrupted inode contents
EXT4-fs error (device loop0) in ext4_orphan_del:305: Corrupt filesystem
EXT4-fs error (device loop0): ext4_do_update_inode:5203: inode #16: comm syz-executor415: corrupted inode contents
EXT4-fs error (device loop0): ext4_truncate:4273: inode #16: comm syz-executor415: mark_inode_dirty error
EXT4-fs error (device loop0) in ext4_process_orphan:347: Corrupt filesystem
EXT4-fs (loop0): 1 truncate cleaned up
EXT4-fs (loop0): mounted filesystem without journal. Opts: ,errors=continue. Quota mode: writeback.
ext4 filesystem being mounted at /root/syzkaller.WY1jCx/70/file1 supports timestamps until 2038-01-19 (0x7fffffff)