EXT4-fs (loop6): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: writeback. ext4 filesystem being mounted at /9/file0 supports timestamps until 2038-01-19 (0x7fffffff) ====================================================== WARNING: possible circular locking dependency detected 6.16.0-syzkaller-08685-g260f6f4fda93 #0 Tainted: G W ------------------------------------------------------ syz.6.164/8087 is trying to acquire lock: ffff88805d3f0298 (&dquot->dq_lock){+.+.}-{4:4}, at: wait_on_dquot fs/quota/dquot.c:354 [inline] ffff88805d3f0298 (&dquot->dq_lock){+.+.}-{4:4}, at: dqget+0x73a/0xf20 fs/quota/dquot.c:972 but task is already holding lock: ffff8880597f53a0 (&ei->xattr_sem){++++}-{4:4}, at: ext4_setattr+0x855/0x1bc0 fs/ext4/inode.c:5811 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #5 (&ei->xattr_sem){++++}-{4:4}: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 down_write+0x3a/0x50 kernel/locking/rwsem.c:1575 ext4_write_lock_xattr fs/ext4/xattr.h:157 [inline] ext4_xattr_set_handle+0x165/0x1590 fs/ext4/xattr.c:2362 ext4_initxattrs+0x9f/0x110 fs/ext4/xattr_security.c:44 security_inode_init_security+0x29d/0x3f0 security/security.c:1852 __ext4_new_inode+0x3257/0x3be0 fs/ext4/ialloc.c:1325 ext4_create+0x22d/0x460 fs/ext4/namei.c:2822 lookup_open fs/namei.c:3708 [inline] open_last_lookups fs/namei.c:3807 [inline] path_openat+0x1500/0x3840 fs/namei.c:4043 do_filp_open+0x1fa/0x410 fs/namei.c:4073 do_sys_openat2+0x121/0x1c0 fs/open.c:1435 do_sys_open fs/open.c:1450 [inline] __do_sys_openat fs/open.c:1466 [inline] __se_sys_openat fs/open.c:1461 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1461 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #4 (jbd2_handle){++++}-{0:0}: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 start_this_handle+0x1fa7/0x21c0 fs/jbd2/transaction.c:444 jbd2__journal_start+0x2c1/0x5b0 fs/jbd2/transaction.c:501 jbd2_journal_start+0x2a/0x40 fs/jbd2/transaction.c:540 ocfs2_start_trans+0x377/0x6d0 fs/ocfs2/journal.c:374 ocfs2_block_group_alloc fs/ocfs2/suballoc.c:685 [inline] ocfs2_reserve_suballoc_bits+0x711/0x4640 fs/ocfs2/suballoc.c:834 ocfs2_reserve_new_metadata_blocks+0x403/0x940 fs/ocfs2/suballoc.c:984 ocfs2_mknod+0xe08/0x2050 fs/ocfs2/namei.c:347 ocfs2_create+0x1a5/0x440 fs/ocfs2/namei.c:673 lookup_open fs/namei.c:3708 [inline] open_last_lookups fs/namei.c:3807 [inline] path_openat+0x1500/0x3840 fs/namei.c:4043 do_filp_open+0x1fa/0x410 fs/namei.c:4073 do_sys_openat2+0x121/0x1c0 fs/open.c:1435 do_sys_open fs/open.c:1450 [inline] __do_sys_openat fs/open.c:1466 [inline] __se_sys_openat fs/open.c:1461 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1461 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #3 (&journal->j_trans_barrier){.+.+}-{4:4}: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 down_read+0x97/0x1f0 kernel/locking/rwsem.c:1522 ocfs2_start_trans+0x36b/0x6d0 fs/ocfs2/journal.c:372 ocfs2_block_group_alloc fs/ocfs2/suballoc.c:685 [inline] ocfs2_reserve_suballoc_bits+0x711/0x4640 fs/ocfs2/suballoc.c:834 ocfs2_reserve_new_metadata_blocks+0x403/0x940 fs/ocfs2/suballoc.c:984 ocfs2_mknod+0xe08/0x2050 fs/ocfs2/namei.c:347 ocfs2_create+0x1a5/0x440 fs/ocfs2/namei.c:673 lookup_open fs/namei.c:3708 [inline] open_last_lookups fs/namei.c:3807 [inline] path_openat+0x1500/0x3840 fs/namei.c:4043 do_filp_open+0x1fa/0x410 fs/namei.c:4073 do_sys_openat2+0x121/0x1c0 fs/open.c:1435 do_sys_open fs/open.c:1450 [inline] __do_sys_openat fs/open.c:1466 [inline] __se_sys_openat fs/open.c:1461 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1461 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #2 (sb_internal#3){.+.+}-{0:0}: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 percpu_down_read_internal include/linux/percpu-rwsem.h:53 [inline] percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline] __sb_start_write include/linux/fs.h:1796 [inline] sb_start_intwrite include/linux/fs.h:1979 [inline] ocfs2_start_trans+0x26b/0x6d0 fs/ocfs2/journal.c:370 ocfs2_acquire_dquot+0x455/0xb30 fs/ocfs2/quota_global.c:860 dqget+0x7be/0xf20 fs/quota/dquot.c:977 __dquot_initialize+0x3b3/0xcb0 fs/quota/dquot.c:1505 ocfs2_get_init_inode+0x13b/0x1b0 fs/ocfs2/namei.c:202 ocfs2_mknod+0x863/0x2050 fs/ocfs2/namei.c:310 ocfs2_mkdir+0x191/0x440 fs/ocfs2/namei.c:656 vfs_mkdir+0x303/0x510 fs/namei.c:4366 do_mkdirat+0x247/0x590 fs/namei.c:4399 __do_sys_mkdirat fs/namei.c:4416 [inline] __se_sys_mkdirat fs/namei.c:4414 [inline] __x64_sys_mkdirat+0x87/0xa0 fs/namei.c:4414 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (&ocfs2_quota_ip_alloc_sem_key){++++}-{4:4}: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 down_write+0x3a/0x50 kernel/locking/rwsem.c:1575 ocfs2_create_local_dquot+0x19d/0x1a40 fs/ocfs2/quota_local.c:1227 ocfs2_acquire_dquot+0x80f/0xb30 fs/ocfs2/quota_global.c:883 dqget+0x7be/0xf20 fs/quota/dquot.c:977 __dquot_initialize+0x3b3/0xcb0 fs/quota/dquot.c:1505 ocfs2_get_init_inode+0x13b/0x1b0 fs/ocfs2/namei.c:202 ocfs2_mknod+0x863/0x2050 fs/ocfs2/namei.c:310 ocfs2_mkdir+0x191/0x440 fs/ocfs2/namei.c:656 vfs_mkdir+0x303/0x510 fs/namei.c:4366 do_mkdirat+0x247/0x590 fs/namei.c:4399 __do_sys_mkdirat fs/namei.c:4416 [inline] __se_sys_mkdirat fs/namei.c:4414 [inline] __x64_sys_mkdirat+0x87/0xa0 fs/namei.c:4414 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&dquot->dq_lock){+.+.}-{4:4}: check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3908 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 __mutex_lock_common kernel/locking/rtmutex_api.c:535 [inline] mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:547 wait_on_dquot fs/quota/dquot.c:354 [inline] dqget+0x73a/0xf20 fs/quota/dquot.c:972 dquot_transfer+0x2f8/0x6d0 fs/quota/dquot.c:2140 ext4_setattr+0x865/0x1bc0 fs/ext4/inode.c:5812 notify_change+0xb31/0xe60 fs/attr.c:552 chown_common+0x40c/0x5c0 fs/open.c:791 do_fchownat+0x161/0x270 fs/open.c:822 __do_sys_lchown fs/open.c:847 [inline] __se_sys_lchown fs/open.c:845 [inline] __x64_sys_lchown+0x85/0xa0 fs/open.c:845 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Chain exists of: &dquot->dq_lock --> jbd2_handle --> &ei->xattr_sem Possible unsafe locking scenario: CPU0 CPU1 ---- ---- rlock(&ei->xattr_sem); lock(jbd2_handle); lock(&ei->xattr_sem); lock(&dquot->dq_lock); *** DEADLOCK *** 3 locks held by syz.6.164/8087: #0: ffff88805b540488 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:557 #1: ffff8880597f5798 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: inode_lock_killable include/linux/fs.h:874 [inline] #1: ffff8880597f5798 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: chown_common+0x313/0x5c0 fs/open.c:779 #2: ffff8880597f53a0 (&ei->xattr_sem){++++}-{4:4}, at: ext4_setattr+0x855/0x1bc0 fs/ext4/inode.c:5811 stack backtrace: CPU: 0 UID: 0 PID: 8087 Comm: syz.6.164 Tainted: G W 6.16.0-syzkaller-08685-g260f6f4fda93 #0 PREEMPT_{RT,(full)} Tainted: [W]=WARN Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_circular_bug+0x2ee/0x310 kernel/locking/lockdep.c:2043 check_noncircular+0x134/0x160 kernel/locking/lockdep.c:2175 check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3908 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 __mutex_lock_common kernel/locking/rtmutex_api.c:535 [inline] mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:547 wait_on_dquot fs/quota/dquot.c:354 [inline] dqget+0x73a/0xf20 fs/quota/dquot.c:972 dquot_transfer+0x2f8/0x6d0 fs/quota/dquot.c:2140 ext4_setattr+0x865/0x1bc0 fs/ext4/inode.c:5812 notify_change+0xb31/0xe60 fs/attr.c:552 chown_common+0x40c/0x5c0 fs/open.c:791 do_fchownat+0x161/0x270 fs/open.c:822 __do_sys_lchown fs/open.c:847 [inline] __se_sys_lchown fs/open.c:845 [inline] __x64_sys_lchown+0x85/0xa0 fs/open.c:845 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fbd59c0eb69 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:00007fbd57a6e038 EFLAGS: 00000246 ORIG_RAX: 000000000000005e RAX: ffffffffffffffda RBX: 00007fbd59e35fa0 RCX: 00007fbd59c0eb69 RDX: 0000000000000000 RSI: 000000003a736e6f RDI: 0000200000000000 RBP: 00007fbd59c91df1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fbd59e35fa0 R15: 00007ffe1e9f1958