INFO: task syz.8.874:11449 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.8.874 state:D stack:25624 pid:11449 tgid:11448 ppid:7292 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5260 [inline] __schedule+0x147b/0x4f50 kernel/sched/core.c:6867 __schedule_loop kernel/sched/core.c:6949 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7245 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1fc5/0x2600 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:1072 [inline] __start_dirop fs/namei.c:2873 [inline] start_dirop fs/namei.c:2884 [inline] filename_create+0x200/0x370 fs/namei.c:4888 do_mkdirat+0xd2/0x4c0 fs/namei.c:5165 __do_sys_mkdirat fs/namei.c:5195 [inline] __se_sys_mkdirat fs/namei.c:5193 [inline] __x64_sys_mkdirat+0x87/0xa0 fs/namei.c:5193 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f3ce2e09b97 RSP: 002b:00007f3ce1065e58 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007f3ce1065ee0 RCX: 00007f3ce2e09b97 RDX: 00000000000001ff RSI: 0000200000000000 RDI: 00000000ffffff9c RBP: 0000000000000000 R08: 0000200000000080 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000200000000000 R13: 00007f3ce1065ea0 R14: 0000000000000000 R15: 0000000000000000 Showing all locks held in the system: 1 lock held by khungtaskd/38: #0: ffffffff8d9aea00 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8d9aea00 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8d9aea00 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 4 locks held by kworker/u8:7/148: #0: ffff8881416a1138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff8881416a1138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340 #1: ffffc90003ae7bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc90003ae7bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340 #2: ffff88803286a0d0 (&type->s_umount_key#91){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563 #3: ffff88806b109f28 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108 3 locks held by kworker/u8:9/1007: #0: ffff888031600138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff888031600138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340 #1: ffffc9000493fbc0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc9000493fbc0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340 #2: ffffffff8eca88b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8eca88b8 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x124/0x1680 net/ipv6/addrconf.c:4194 2 locks held by dhcpcd/5461: #0: ffffffff8ed10f20 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8eca88b8 (rtnl_mutex){+.+.}-{4:4}, at: nl80211_pre_doit+0x5f/0x930 net/wireless/nl80211.c:17932 2 locks held by getty/5556: #0: ffff8880316560a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e7e2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13c0 drivers/tty/n_tty.c:2211 8 locks held by kworker/u8:23/7972: 2 locks held by syz.8.874/11449: #0: ffff88803286a480 (sb_writers#30){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499 #1: ffff88806b10a2f8 (&type->i_mutex_dir_key#22/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1072 [inline] #1: ffff88806b10a2f8 (&type->i_mutex_dir_key#22/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2873 [inline] #1: ffff88806b10a2f8 (&type->i_mutex_dir_key#22/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2884 [inline] #1: ffff88806b10a2f8 (&type->i_mutex_dir_key#22/1){+.+.}-{4:4}, at: filename_create+0x200/0x370 fs/namei.c:4888 4 locks held by syz.8.874/11453: 1 lock held by syz-executor/12073: #0: ffffffff8eca88b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8eca88b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8eca88b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a1/0x1be0 net/core/rtnetlink.c:4071 1 lock held by syz-executor/12076: #0: ffffffff8eca88b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8eca88b8 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x404/0x1ad0 net/ipv4/devinet.c:978 2 locks held by syz-executor/12114: #0: ffffffff8f1d5fc8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8f1d5fc8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8f1d5fc8 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8eca88b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8eca88b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8eca88b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a1/0x1be0 net/core/rtnetlink.c:4071 2 locks held by syz-executor/12126: #0: ffffffff8e422448 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e422448 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e422448 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8eca88b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8eca88b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8eca88b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a1/0x1be0 net/core/rtnetlink.c:4071 2 locks held by syz-executor/12135: ============================================= 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 10/25/2025 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+0xf90/0xfe0 kernel/hung_task.c:515 kthread+0x726/0x8b0 kernel/kthread.c:463 ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 11453 Comm: syz.8.874 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x80 kernel/kcov.c:210 Code: 89 fb e8 23 00 00 00 48 8b 3d 84 e9 6a 0b 48 89 de 5b e9 f3 02 58 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 48 8b 04 24 65 48 8b 0d 68 13 33 10 65 8b 35 89 13 33 RSP: 0018:ffffc900052df6a0 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000080000 RDX: ffffc9000e099000 RSI: 000000000007ffff RDI: 0000000000080000 RBP: ffff88807df75000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000 R13: 1ffff1100fbeea00 R14: 0000000000000000 R15: 1ffff1100fbeea02 FS: 00007f3ce10456c0(0000) GS:ffff8881269d9000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2679a735c0 CR3: 000000002a796000 CR4: 00000000003526f0 Call Trace: dtSplitRoot+0x7a6/0x16c0 fs/jfs/jfs_dtree.c:1981 dtSplitUp fs/jfs/jfs_dtree.c:993 [inline] dtInsert+0xedd/0x5de0 fs/jfs/jfs_dtree.c:871 jfs_create+0x75b/0xb10 fs/jfs/namei.c:137 vfs_create+0x3b1/0x410 fs/namei.c:4141 do_mknodat+0x3f5/0x630 fs/namei.c:5048 __do_sys_mknod fs/namei.c:5085 [inline] __se_sys_mknod fs/namei.c:5083 [inline] __x64_sys_mknod+0x8c/0xa0 fs/namei.c:5083 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f3ce2e0acb9 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:00007f3ce1045028 EFLAGS: 00000246 ORIG_RAX: 0000000000000085 RAX: ffffffffffffffda RBX: 00007f3ce3086090 RCX: 00007f3ce2e0acb9 RDX: 0000000000000711 RSI: 0000000000000000 RDI: 0000200000000000 RBP: 00007f3ce2e78bf7 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f3ce3086128 R14: 00007f3ce3086090 R15: 00007ffd74a848a8