INFO: task syz.3.110:6710 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.110 state:D stack:24064 pid:6710 tgid:6702 ppid:5802 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x1553/0x5240 kernel/sched/core.c:6908 __schedule_loop kernel/sched/core.c:6990 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7286 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1f8f/0x25c0 kernel/locking/rtmutex.c:1760 rt_mutex_slowlock+0xbd/0x170 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] rwbase_write_lock+0x14d/0x730 kernel/locking/rwbase_rt.c:244 inode_lock_nested include/linux/fs.h:1073 [inline] __start_dirop fs/namei.c:2923 [inline] start_dirop fs/namei.c:2934 [inline] filename_create+0x200/0x370 fs/namei.c:4922 filename_mkdirat+0xd2/0x520 fs/namei.c:5259 __do_sys_mkdirat fs/namei.c:5287 [inline] __se_sys_mkdirat+0x35/0x150 fs/namei.c:5284 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7006ddb607 RSP: 002b:00007f7005035e58 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007f7005035ee0 RCX: 00007f7006ddb607 RDX: 00000000000001ff RSI: 0000200000000040 RDI: 00000000ffffff9c RBP: 0000200000000140 R08: 00002000000000c0 R09: 0000000000000000 R10: 0000200000000140 R11: 0000000000000246 R12: 0000200000000040 R13: 00007f7005035ea0 R14: 0000000000000000 R15: 0000000000000000 Showing all locks held in the system: 1 lock held by khungtaskd/38: #0: ffffffff8ddcb8c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8ddcb8c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8ddcb8c0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5562: #0: ffff888032d7d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e8b2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13c0 drivers/tty/n_tty.c:2211 2 locks held by syz.3.110/6710: #0: ffff88803f40e480 (sb_writers#4){++++}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 #1: ffff88805fd39090 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1073 [inline] #1: ffff88805fd39090 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2923 [inline] #1: ffff88805fd39090 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2934 [inline] #1: ffff88805fd39090 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: filename_create+0x200/0x370 fs/namei.c:4922 7 locks held by syz.3.110/6726: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline] watchdog+0xfd9/0x1030 kernel/hung_task.c:515 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 6726 Comm: syz.3.110 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x2c/0x80 kernel/kcov.c:217 Code: 1e fa 48 8b 04 24 65 48 8b 0d e8 d9 89 10 65 8b 35 09 da 89 10 81 e6 00 00 ff 00 ba 00 01 00 00 23 91 a4 0b 00 00 89 d7 09 f7 <74> 11 85 f6 75 39 85 d2 74 35 83 b9 64 16 00 00 00 74 2c 8b 91 40 RSP: 0018:ffffc9000626ef50 EFLAGS: 00000246 RAX: ffffffff827cc8aa RBX: 0000000000000080 RCX: ffff88802c4ddb80 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000009 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: fffffbfff1ed4757 R12: 0000000000000014 R13: 0000000000000016 R14: dffffc0000000000 R15: ffff88805fdeee18 FS: 00007f70050156c0(0000) GS:ffff88812643c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000559ae0c46120 CR3: 000000003e0f8000 CR4: 00000000003526f0 Call Trace: ext4_update_other_inodes_time fs/ext4/inode.c:5522 [inline] ext4_do_update_inode fs/ext4/inode.c:5574 [inline] ext4_mark_iloc_dirty+0x98a/0x1cf0 fs/ext4/inode.c:6215 __ext4_mark_inode_dirty+0x4ae/0x730 fs/ext4/inode.c:6421 ext4_dirty_inode+0xd0/0x110 fs/ext4/inode.c:6450 __mark_inode_dirty+0x3a4/0x1470 fs/fs-writeback.c:2609 mark_inode_dirty include/linux/fs.h:2212 [inline] dquot_alloc_space include/linux/quotaops.h:319 [inline] dquot_alloc_block include/linux/quotaops.h:336 [inline] ext4_xattr_block_set+0x12d0/0x2ad0 fs/ext4/xattr.c:2058 ext4_xattr_set_handle+0xe34/0x14c0 fs/ext4/xattr.c:2457 ext4_initxattrs+0x9f/0x110 fs/ext4/xattr_security.c:44 security_inode_init_security+0x296/0x3d0 security/security.c:1344 __ext4_new_inode+0x332f/0x3d20 fs/ext4/ialloc.c:1324 ext4_create+0x233/0x470 fs/ext4/namei.c:2820 lookup_open fs/namei.c:4483 [inline] open_last_lookups fs/namei.c:4583 [inline] path_openat+0x13b4/0x38a0 fs/namei.c:4827 do_file_open+0x23e/0x4a0 fs/namei.c:4859 do_sys_openat2+0x113/0x200 fs/open.c:1366 do_sys_open fs/open.c:1372 [inline] __do_sys_openat fs/open.c:1388 [inline] __se_sys_openat fs/open.c:1383 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1383 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7006ddc799 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f7005015028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f7007056090 RCX: 00007f7006ddc799 RDX: 000000000000275a RSI: 0000200000000000 RDI: ffffffffffffff9c RBP: 00007f7006e72c99 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f7007056128 R14: 00007f7007056090 R15: 00007ffd4762add8