INFO: task syz.1.131:6916 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.131 state:D stack:29024 pid:6916 tgid:6896 ppid:5797 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x1553/0x5240 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7289 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: 0033:0x7fbfcaebb607 RSP: 002b:00007fbfc90d3e58 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007fbfc90d3ee0 RCX: 00007fbfcaebb607 RDX: 00000000000001ff RSI: 0000200000000040 RDI: 00000000ffffff9c RBP: 0000200000000140 R08: 00002000000000c0 R09: 0000000000000000 R10: 0000200000000140 R11: 0000000000000246 R12: 0000200000000040 R13: 00007fbfc90d3ea0 R14: 0000000000000000 R15: 0000000000000000 Showing all locks held in the system: 3 locks held by kworker/0:0/9: 1 lock held by khungtaskd/39: #0: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5555: #0: ffff888036ac80a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e832e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13c0 drivers/tty/n_tty.c:2211 2 locks held by syz-executor/6227: #0: ffff88806314c0d0 (&type->s_umount_key#102){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff88806314c0d0 (&type->s_umount_key#102){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff88806314c0d0 (&type->s_umount_key#102){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508 #1: ffffffff8e24dbd8 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443 6 locks held by syz.1.131/6898: 2 locks held by syz.1.131/6916: #0: ffff88802a068480 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 #1: ffff888060713430 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1073 [inline] #1: ffff888060713430 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2923 [inline] #1: ffff888060713430 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2934 [inline] #1: ffff888060713430 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: filename_create+0x200/0x370 fs/namei.c:4922 2 locks held by syz-executor/7961: #0: ffff8880299580d0 (&type->s_umount_key#102){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff8880299580d0 (&type->s_umount_key#102){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff8880299580d0 (&type->s_umount_key#102){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508 #1: ffffffff8e24dbd8 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443 2 locks held by syz-executor/8181: #0: ffff888028e9e0d0 (&type->s_umount_key#102){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff888028e9e0d0 (&type->s_umount_key#102){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff888028e9e0d0 (&type->s_umount_key#102){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508 #1: ffffffff8e24dbd8 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443 1 lock held by udevd/8215: 7 locks held by syz-executor/8523: 3 locks held by syz.2.285/8564: 2 locks held by syz.1.287/8571: 3 locks held by syz.3.286/8575: 2 locks held by rm/8580: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 39 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 8575 Comm: syz.3.286 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:trace_lock_acquire include/trace/events/lock.h:24 [inline] RIP: 0010:lock_acquire+0x50/0x2e0 kernel/locking/lockdep.c:5831 Code: 8b 05 24 0a ae 10 48 89 44 24 30 0f 1f 44 00 00 65 8b 05 27 0a ae 10 83 f8 08 0f 83 77 01 00 00 89 c0 48 0f a3 05 90 07 ca 0d <73> 0d e8 c9 42 09 00 84 c0 0f 84 bc 01 00 00 83 3d aa 1a ca 0d 00 RSP: 0018:ffffc90003bbf668 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 1ffff92000777ee0 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88802b6f3c58 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000 R10: dffffc0000000000 R11: fffffbfff1ed4892 R12: 0000000000000000 R13: ffff88802b6f3c58 R14: 0000000000000000 R15: 0000000000000001 FS: 00007f2ba97166c0(0000) GS:ffff88812633c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f5b654d2000 CR3: 0000000061488000 CR4: 00000000003526f0 Call Trace: rt_spin_lock+0x83/0x400 kernel/locking/spinlock_rt.c:56 spin_lock include/linux/spinlock_rt.h:45 [inline] inode_add_bytes+0x38/0x140 fs/stat.c:919 __dquot_alloc_space+0x285/0xea0 fs/quota/dquot.c:1698 dquot_alloc_space_nodirty include/linux/quotaops.h:299 [inline] dquot_alloc_block_nodirty include/linux/quotaops.h:326 [inline] shmem_inode_acct_blocks+0x2a1/0x460 mm/shmem.c:242 shmem_alloc_and_add_folio mm/shmem.c:2002 [inline] shmem_get_folio_gfp+0x90d/0x1a80 mm/shmem.c:2567 shmem_get_folio mm/shmem.c:2673 [inline] shmem_write_begin+0x166/0x320 mm/shmem.c:3327 generic_perform_write+0x2af/0x8b0 mm/filemap.c:4319 shmem_file_write_iter+0xfb/0x120 mm/shmem.c:3502 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x629/0xba0 fs/read_write.c:688 ksys_write+0x156/0x270 fs/read_write.c:740 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: 0033:0x7f2bab47cfce Code: 08 0f 85 a5 a8 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08 RSP: 002b:00007f2ba9715da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f2ba97166c0 RCX: 00007f2bab47cfce RDX: 0000000001000000 RSI: 00007f2ba12f6000 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003 R13: 00007f2ba9715ee0 R14: 00007f2ba9715ea0 R15: 00007f2ba12f6000