EXT4-fs (loop3): mounted filesystem without journal. Opts: sysvgroups,noload,nobh,noload,journal_dev=0x0000000000000004,norecovery,errors=continue,quota,,errors=continue. Quota mode: writeback. kvm: emulating exchange as write ====================================================== WARNING: possible circular locking dependency detected 5.15.187-syzkaller #0 Not tainted ------------------------------------------------------ syz.3.1090/8755 is trying to acquire lock: ffff88805fde8278 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_map_blocks+0x8b2/0x1b30 fs/ext4/inode.c:666 but task is already holding lock: ffff88807ae7e208 (&s->s_dquot.dqio_sem){++++}-{3:3}, at: v2_write_dquot+0x12b/0x190 fs/quota/quota_v2.c:354 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&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:6203 dqget+0x778/0xeb0 fs/quota/dquot.c:988 __dquot_initialize+0x3b6/0xcb0 fs/quota/dquot.c:1517 ext4_create+0x8c/0x460 fs/ext4/namei.c:2876 lookup_open fs/namei.c:3462 [inline] open_last_lookups fs/namei.c:3532 [inline] path_openat+0x11e1/0x2f30 fs/namei.c:3739 do_filp_open+0x1b3/0x3e0 fs/namei.c:3769 do_sys_openat2+0x142/0x4a0 fs/open.c:1253 do_sys_open fs/open.c:1269 [inline] __do_sys_openat fs/open.c:1285 [inline] __se_sys_openat fs/open.c:1280 [inline] __x64_sys_openat+0x135/0x160 fs/open.c:1280 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 (&dquot->dq_lock){+.+.}-{3:3}: __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:6183 mark_dquot_dirty fs/quota/dquot.c:372 [inline] mark_all_dquot_dirty+0xf9/0x400 fs/quota/dquot.c:412 __dquot_alloc_space+0x5d0/0xe20 fs/quota/dquot.c:1752 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+0xf68/0x4940 fs/ext4/mballoc.c:5739 ext4_ext_map_blocks+0x146f/0x64e0 fs/ext4/extents.c:4341 ext4_map_blocks+0x981/0x1b30 fs/ext4/inode.c:673 _ext4_get_block+0x1d7/0x4e0 fs/ext4/inode.c:816 ext4_block_write_begin+0x60f/0x1210 fs/ext4/inode.c:1101 ext4_write_begin+0x6c2/0x15c0 fs/ext4/ext4_jbd2.h:-1 ext4_da_write_begin+0x435/0xb30 fs/ext4/inode.c:2975 generic_perform_write+0x2aa/0x530 mm/filemap.c:3785 ext4_buffered_write_iter+0x25f/0x3b0 fs/ext4/file.c:268 ext4_file_write_iter+0x773/0x17b0 fs/ext4/file.c:-1 call_write_iter include/linux/fs.h:2172 [inline] new_sync_write fs/read_write.c:507 [inline] vfs_write+0x712/0xd00 fs/read_write.c:594 ksys_write+0x14d/0x250 fs/read_write.c:647 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 (&ei->i_data_sem/2){++++}-{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 down_write+0x38/0x60 kernel/locking/rwsem.c:1551 ext4_map_blocks+0x8b2/0x1b30 fs/ext4/inode.c:666 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:6594 write_blk fs/quota/quota_tree.c:64 [inline] find_free_dqentry fs/quota/quota_tree.c:307 [inline] do_insert_tree+0x115c/0x1970 fs/quota/quota_tree.c:364 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:6203 dqget+0x778/0xeb0 fs/quota/dquot.c:988 dquot_set_dqblk+0x27/0xf90 fs/quota/dquot.c:2826 quota_setquota+0x4ac/0x530 fs/quota/quota.c:309 __do_sys_quotactl fs/quota/quota.c:959 [inline] __se_sys_quotactl+0x295/0x6c0 fs/quota/quota.c:915 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: &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 *** 3 locks held by syz.3.1090/8755: #0: ffff88807ae7e0e0 (&type->s_umount_key#32){++++}-{3:3}, at: user_get_super+0x118/0x240 fs/super.c:850 #1: ffff8880595520a8 (&dquot->dq_lock){+.+.}-{3:3}, at: dquot_acquire+0x63/0x520 fs/quota/dquot.c:460 #2: ffff88807ae7e208 (&s->s_dquot.dqio_sem){++++}-{3:3}, at: v2_write_dquot+0x12b/0x190 fs/quota/quota_v2.c:354 stack backtrace: CPU: 0 PID: 8755 Comm: syz.3.1090 Not tainted 5.15.187-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: 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 down_write+0x38/0x60 kernel/locking/rwsem.c:1551 ext4_map_blocks+0x8b2/0x1b30 fs/ext4/inode.c:666 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:6594 write_blk fs/quota/quota_tree.c:64 [inline] find_free_dqentry fs/quota/quota_tree.c:307 [inline] do_insert_tree+0x115c/0x1970 fs/quota/quota_tree.c:364 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:6203 dqget+0x778/0xeb0 fs/quota/dquot.c:988 dquot_set_dqblk+0x27/0xf90 fs/quota/dquot.c:2826 quota_setquota+0x4ac/0x530 fs/quota/quota.c:309 __do_sys_quotactl fs/quota/quota.c:959 [inline] __se_sys_quotactl+0x295/0x6c0 fs/quota/quota.c:915 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: 0033:0x7f4825b3a929 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:00007f48239a2038 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3 RAX: ffffffffffffffda RBX: 00007f4825d61fa0 RCX: 00007f4825b3a929 RDX: 0000000000000000 RSI: 0000200000002540 RDI: ffffffff80000800 RBP: 00007f4825bbcb39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000200000000140 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f4825d61fa0 R15: 00007fffd39e4c98 Quota error (device loop3): write_blk: dquota write failed Quota error (device loop3): qtree_write_dquot: Error -28 occurred while creating quota EXT4-fs error (device loop3): ext4_acquire_dquot:6207: comm syz.3.1090: Failed to acquire dquot type 0