INFO: task syz-executor:5805 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:20872 pid:5805 tgid:5805 ppid:1 task_flags:0x400140 flags:0x00080003 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7307 rt_mutex_slowlock_block+0x5ba/0x6d0 kernel/locking/rtmutex.c:1647 __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1760 [inline] rt_mutex_slowlock+0x2b1/0x6e0 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] __mutex_lock_common kernel/locking/rtmutex_api.c:536 [inline] mutex_lock_nested+0x16a/0x1d0 kernel/locking/rtmutex_api.c:547 lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443 jfs_umount+0x2ef/0x3c0 fs/jfs/jfs_umount.c:114 jfs_put_super+0x8c/0x190 fs/jfs/super.c:194 generic_shutdown_super+0x135/0x2c0 fs/super.c:642 kill_block_super+0x44/0x90 fs/super.c:1722 deactivate_locked_super+0xbc/0x130 fs/super.c:473 cleanup_mnt+0x425/0x4c0 fs/namespace.c:1327 task_work_run+0x1d4/0x260 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xe9/0x130 kernel/entry/common.c:43 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x2bd/0xfa0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fdd894601f7 RSP: 002b:00007ffd94ac5eb8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007fdd894e1d7d RCX: 00007fdd894601f7 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd94ac5f70 RBP: 00007ffd94ac5f70 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffd94ac7000 R13: 00007fdd894e1d7d R14: 0000000000026c4c R15: 00007ffd94ac7040 Showing all locks held in the system: 1 lock held by khungtaskd/38: #0: ffffffff8d7aa4c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8d7aa4c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8d7aa4c0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 4 locks held by kworker/u8:2/43: #0: ffff88801a294938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88801a294938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc90000b47ba0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc90000b47ba0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffffffff8ea6a9e0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x820 net/core/net_namespace.c:669 #3: ffffffff8ea778f8 (rtnl_mutex){+.+.}-{4:4}, at: wg_netns_pre_exit+0x1c/0x1d0 drivers/net/wireguard/device.c:419 2 locks held by getty/5561: #0: ffff88823bf468a0 (&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+0x444/0x1400 drivers/tty/n_tty.c:2222 2 locks held by syz-executor/5796: #0: ffff88801a3ba0d0 (&type->s_umount_key#58){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff88801a3ba0d0 (&type->s_umount_key#58){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff88801a3ba0d0 (&type->s_umount_key#58){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:505 #1: ffffffff8dbe19f8 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443 2 locks held by syz-executor/5805: #0: ffff88805cb420d0 (&type->s_umount_key#58){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff88805cb420d0 (&type->s_umount_key#58){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff88805cb420d0 (&type->s_umount_key#58){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:505 #1: ffffffff8dbe19f8 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443 2 locks held by syz-executor/6923: #0: ffff88802744a0d0 (&type->s_umount_key#58){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff88802744a0d0 (&type->s_umount_key#58){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff88802744a0d0 (&type->s_umount_key#58){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:505 #1: ffffffff8dbe19f8 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443 2 locks held by syz-executor/6926: #0: ffff888033a1c0d0 (&type->s_umount_key#58){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff888033a1c0d0 (&type->s_umount_key#58){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff888033a1c0d0 (&type->s_umount_key#58){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:505 #1: ffffffff8dbe19f8 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443 1 lock held by syz-executor/8047: #0: ffffffff8ea778f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8ea778f8 (rtnl_mutex){+.+.}-{4:4}, at: inet6_rtm_newaddr+0x5b7/0xd20 net/ipv6/addrconf.c:5027 2 locks held by syz-executor/8215: #0: ffffffff8ef78710 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8ef78710 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8ef78710 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8ea778f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8ea778f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8ea778f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8e9/0x1c80 net/core/rtnetlink.c:4064 3 locks held by kworker/u8:16/8217: #0: ffff88814ced0138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88814ced0138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc9001007fba0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc9001007fba0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffffffff8ea778f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8ea778f8 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x119/0x15a0 net/ipv6/addrconf.c:4194 2 locks held by syz-executor/8237: #0: ffffffff8e202ba0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e202ba0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e202ba0 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8ea778f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8ea778f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8ea778f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8e9/0x1c80 net/core/rtnetlink.c:4064 2 locks held by syz-executor/8241: #0: ffffffff8e202ba0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e202ba0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e202ba0 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8ea778f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8ea778f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8ea778f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8e9/0x1c80 net/core/rtnetlink.c:4064 2 locks held by syz-executor/8316: #0: ffffffff8e202ba0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e202ba0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e202ba0 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8ea778f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8ea778f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8ea778f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8e9/0x1c80 net/core/rtnetlink.c:4064 1 lock held by dhcpcd-run-hook/8411: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline] watchdog+0xf60/0xfa0 kernel/hung_task.c:495 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 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: 8422 Comm: dhcpcd-run-hook Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0033:0x7f7e5a0cd2c2 Code: 00 49 89 c5 84 db 0f 84 bc 02 00 00 e8 57 b3 ff ff 89 c3 85 c0 0f 85 d5 01 00 00 48 83 05 8d 15 10 00 04 48 8b 1d c6 ac 0f 00 <48> 8b 83 38 0b 00 00 66 0f ef c0 48 c7 83 28 0a 00 00 00 00 00 00 RSP: 002b:00007ffe1f726080 EFLAGS: 00000202 RAX: 0000000000000000 RBX: 00007f7e5a2d8000 RCX: 00007f7e5a036f07 RDX: 0000000000000000 RSI: 00007ffe1f726058 RDI: 0000000000000002 RBP: 00005655582c3e60 R08: 00007f7e5a1c9b60 R09: 0000000000000000 R10: 0000000000000008 R11: 0000000000000246 R12: 00005655582c7b40 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f7e59f2ec80 GS: 0000000000000000