INFO: task syz.8.960:12873 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.8.960 state:D stack:29024 pid:12873 tgid:12844 ppid:10586 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:2929 [inline] start_dirop fs/namei.c:2940 [inline] filename_create+0x200/0x370 fs/namei.c:4928 filename_symlinkat+0xf7/0x420 fs/namei.c:5640 __do_sys_symlinkat fs/namei.c:5666 [inline] __se_sys_symlinkat+0x4e/0x2b0 fs/namei.c:5661 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: 0033:0x7fa95b80c819 RSP: 002b:00007fa959a3d028 EFLAGS: 00000246 ORIG_RAX: 000000000000010a RAX: ffffffffffffffda RBX: 00007fa95ba86090 RCX: 00007fa95b80c819 RDX: 0000200000000000 RSI: ffffffffffffff9c RDI: 0000200000002040 RBP: 00007fa95b8a2c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fa95ba86128 R14: 00007fa95ba86090 R15: 00007ffd14ce9608 Showing all locks held in the system: 3 locks held by kworker/u8:0/12: #0: ffff888019c44138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3263 [inline] #0: ffff888019c44138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3371 #1: ffffc90000117c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3264 [inline] #1: ffffc90000117c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3371 #2: ffffffff8f15d578 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313 2 locks held by kworker/u8:1/13: #0: ffff888019c44938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3263 [inline] #0: ffff888019c44938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3371 #1: ffffc90000127c40 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3264 [inline] #1: ffffc90000127c40 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3371 1 lock held by khungtaskd/38: #0: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:847 [inline] #0: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 3 locks held by kworker/u8:2/43: #0: ffff888031f2c138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3263 [inline] #0: ffff888031f2c138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3371 #1: ffffc90000b47c40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3264 [inline] #1: ffffc90000b47c40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3371 #2: ffffffff8f15d578 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8f15d578 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x124/0x1680 net/ipv6/addrconf.c:4198 4 locks held by kworker/u8:10/1463: #0: ffff88801aac4138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3263 [inline] #0: ffff88801aac4138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3371 #1: ffffc90006037c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3264 [inline] #1: ffffc90006037c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3371 #2: ffff8880207a80d0 (&type->s_umount_key#64){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:565 #3: ffff888068110ba8 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108 2 locks held by kworker/u8:11/2313: #0: ffff888019c44938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3263 [inline] #0: ffff888019c44938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3371 #1: ffffc900073dfc40 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3264 [inline] #1: ffffc900073dfc40 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3371 2 locks held by dhcpcd/5456: #0: ffffffff8f13ead8 (vlan_ioctl_mutex){+.+.}-{4:4}, at: sock_ioctl+0x644/0x7f0 net/socket.c:1337 #1: ffffffff8f15d578 (rtnl_mutex){+.+.}-{4:4}, at: vlan_ioctl_handler+0xf0/0x630 net/8021q/vlan.c:579 2 locks held by getty/5552: #0: ffff88803731e0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e762e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13c0 drivers/tty/n_tty.c:2211 4 locks held by syz.8.960/12845: 2 locks held by syz.8.960/12873: #0: ffff8880207a8480 (sb_writers#16){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 #1: ffff888068110f78 (&type->i_mutex_dir_key#10/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1073 [inline] #1: ffff888068110f78 (&type->i_mutex_dir_key#10/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2929 [inline] #1: ffff888068110f78 (&type->i_mutex_dir_key#10/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2940 [inline] #1: ffff888068110f78 (&type->i_mutex_dir_key#10/1){+.+.}-{4:4}, at: filename_create+0x200/0x370 fs/namei.c:4928 1 lock held by syz-executor/13043: 2 locks held by syz.1.1119/14456: #0: ffff8880207a80d0 (&type->s_umount_key#64){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff8880207a80d0 (&type->s_umount_key#64){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 #1: ffff8880260808c0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:398 [inline] #1: ffff8880260808c0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x209/0xc30 fs/fs-writeback.c:2940 8 locks held by syz-executor/14654: 5 locks held by syz.4.1168/14830: 3 locks held by syz.4.1168/14831: #0: ffff88802557a860 (&fc->uapi_mutex){+.+.}-{4:4}, at: __do_sys_fsconfig fs/fsopen.c:461 [inline] #0: ffff88802557a860 (&fc->uapi_mutex){+.+.}-{4:4}, at: __se_sys_fsconfig+0x6a3/0x820 fs/fsopen.c:350 #1: ffff88802c2560d0 (&type->s_umount_key#41/1){+.+.}-{4:4}, at: alloc_super+0x28c/0xac0 fs/super.c:345 #2: ffffffff8de70798 (bpf_preload_lock){+.+.}-{4:4}, at: populate_bpffs kernel/bpf/inode.c:972 [inline] #2: ffffffff8de70798 (bpf_preload_lock){+.+.}-{4:4}, at: bpf_fill_super+0x281/0xa60 kernel/bpf/inode.c:1019 1 lock held by syz.4.1168/14838: #0: ffff88802557a860 (&fc->uapi_mutex){+.+.}-{4:4}, at: class_mutex_intr_constructor include/linux/mutex.h:255 [inline] #0: ffff88802557a860 (&fc->uapi_mutex){+.+.}-{4:4}, at: __do_sys_fsmount fs/namespace.c:4450 [inline] #0: ffff88802557a860 (&fc->uapi_mutex){+.+.}-{4:4}, at: __se_sys_fsmount+0x346/0xb40 fs/namespace.c:4406 1 lock held by syz.4.1168/14861: #0: ffff88802557a860 (&fc->uapi_mutex){+.+.}-{4:4}, at: __do_sys_fsconfig fs/fsopen.c:461 [inline] #0: ffff88802557a860 (&fc->uapi_mutex){+.+.}-{4:4}, at: __se_sys_fsconfig+0x6a3/0x820 fs/fsopen.c:350 5 locks held by syz.9.1171/14857: 2 locks held by modprobe/14860: ============================================= 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 03/18/2026 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: 12845 Comm: syz.8.960 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 RIP: 0010:get_current arch/x86/include/asm/current.h:25 [inline] RIP: 0010:write_comp_data kernel/kcov.c:245 [inline] RIP: 0010:__sanitizer_cov_trace_const_cmp1+0x8/0xa0 kernel/kcov.c:300 Code: 89 44 0a 20 c3 cc cc cc cc cc 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 0d e8 56 8a 10 65 44 8b 05 08 57 8a 10 41 81 e0 00 00 ff RSP: 0018:ffffc90004caf6a0 EFLAGS: 00000246 RAX: ffffffff8352af75 RBX: 0000000000000004 RCX: 0000000000080000 RDX: ffffc90006039000 RSI: 0000000000000000 RDI: 00000000000000ff RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0030000000000000 R11: 000007ff00000020 R12: dffffc0000000000 R13: ffff88804e465000 R14: 0000000000000000 R15: 1ffff11009c8ca02 FS: 00007fa959a5e6c0(0000) GS:ffff888126432000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f5c1aead000 CR3: 000000002070a000 CR4: 00000000003526f0 Call Trace: dtSplitRoot+0x775/0x16c0 fs/jfs/jfs_dtree.c:1979 dtSplitUp fs/jfs/jfs_dtree.c:993 [inline] dtInsert+0xf19/0x5f10 fs/jfs/jfs_dtree.c:871 jfs_mknod+0x6bd/0x9d0 fs/jfs/namei.c:1413 vfs_mknod+0x44e/0x620 fs/namei.c:5098 filename_mknodat+0x3cf/0x670 fs/namei.c:-1 __do_sys_mknod fs/namei.c:5185 [inline] __se_sys_mknod+0x3a/0x150 fs/namei.c:5182 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: 0033:0x7fa95b80c819 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:00007fa959a5e028 EFLAGS: 00000246 ORIG_RAX: 0000000000000085 RAX: ffffffffffffffda RBX: 00007fa95ba85fa0 RCX: 00007fa95b80c819 RDX: 0000000000000000 RSI: 0000000000001000 RDI: 00002000000000c0 RBP: 00007fa95b8a2c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fa95ba86038 R14: 00007fa95ba85fa0 R15: 00007ffd14ce9608