INFO: task syz-executor:5842 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:18712 pid:5842 tgid:5842 ppid:1 task_flags:0x400140 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5357 [inline][ 408.757365][ T38] __schedule+0x16f3/0x4c20 __schedule+0x16f3/0x4c20 kernel/sched/core.c:6961[ 408.757365][ T38] __schedule+0x16f3/0x4c20 __schedule_loop kernel/sched/core.c:7043 [inline] rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7339 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:1444 jfs_umount+0x2ef/0x3c0 fs/jfs/jfs_umount.c:114 jfs_put_super+0x8c/0x190 fs/jfs/super.c:194 generic_shutdown_super+0x132/0x2c0 fs/super.c:643 kill_block_super+0x44/0x90 fs/super.c:1766 deactivate_locked_super+0xbc/0x130 fs/super.c:474 cleanup_mnt+0x425/0x4c0 fs/namespace.c:1375 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+0xec/0x110 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/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f44c637ff17 RSP: 002b:00007ffcb3c4fd58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f44c6401c05 RCX: 00007f44c637ff17 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffcb3c4fe10 RBP: 00007ffcb3c4fe10 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffcb3c50ea0 R13: 00007f44c6401c05 R14: 0000000000030f29 R15: 00007ffcb3c50ee0 INFO: task syz.6.216:7448 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.6.216 state:D stack:25048 pid:7448 tgid:7447 ppid:6905 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7339 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:1444 jfs_umount+0x2ef/0x3c0 fs/jfs/jfs_umount.c:114 jfs_fill_super+0x9c5/0xd80 fs/jfs/super.c:567 get_tree_bdev_flags+0x40e/0x4d0 fs/super.c:1692 vfs_get_tree+0x92/0x2b0 fs/super.c:1815 do_new_mount+0x2a2/0x9e0 fs/namespace.c:3808 do_mount fs/namespace.c:4136 [inline] __do_sys_mount fs/namespace.c:4347 [inline] __se_sys_mount+0x317/0x410 fs/namespace.c:4324 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff67ac1038a RSP: 002b:00007ff678e6de68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007ff678e6def0 RCX: 00007ff67ac1038a RDX: 0000200000000240 RSI: 0000200000000080 RDI: 00007ff678e6deb0 RBP: 0000200000000240 R08: 00007ff678e6def0 R09: 0000000002010880 R10: 0000000002010880 R11: 0000000000000246 R12: 0000200000000080 R13: 00007ff678e6deb0 R14: 0000000000006203 R15: 00002000000000c0 Showing all locks held in the system: 3 locks held by kworker/u8:1/13: #0: ffff88814d41a138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff88814d41a138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc90000127bc0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc90000127bc0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 #2: ffffffff8ecd3178 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8ecd3178 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x119/0x15a0 net/ipv6/addrconf.c:4194 1 lock held by khungtaskd/38: #0: ffffffff8d9a8bc0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8d9a8bc0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8d9a8bc0 (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: 3 locks held by kworker/1:1/44: #0: ffff888019898538 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff888019898538 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc90000b57bc0 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc90000b57bc0 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 #2: ffffffff8ecd3178 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104 3 locks held by kworker/u8:5/151: #0: ffff888019881138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff888019881138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc90003a4fbc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc90003a4fbc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 #2: ffffffff8ecd3178 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 4 locks held by kworker/u8:14/4522: 2 locks held by dhcpcd/5505: #0: ffff8880284fc910 (nlk_cb_mutex-ROUTE){+.+.}-{4:4}, at: netlink_dump+0xbd/0xe90 net/netlink/af_netlink.c:2269 #1: ffffffff8ecd3178 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8ecd3178 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dumpit+0x92/0x200 net/core/rtnetlink.c:6814 2 locks held by getty/5601: #0: ffff88823bf3c8a0 (&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+0x444/0x1410 drivers/tty/n_tty.c:2222 2 locks held by syz-executor/5840: #0: ffff88803327c0d0 (&type->s_umount_key#60){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff88803327c0d0 (&type->s_umount_key#60){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff88803327c0d0 (&type->s_umount_key#60){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506 #1: ffffffff8ddd3798 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1444 2 locks held by syz-executor/5842: #0: ffff8880233f60d0 (&type->s_umount_key#60){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff8880233f60d0 (&type->s_umount_key#60){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff8880233f60d0 (&type->s_umount_key#60){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506 #1: ffffffff8ddd3798 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1444 1 lock held by syz.5.159/6999: #0: ffff88803327c0d0 (&type->s_umount_key#60){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff88803327c0d0 (&type->s_umount_key#60){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 2 locks held by syz-executor/7047: #0: ffff888038a580d0 (&type->s_umount_key#60){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff888038a580d0 (&type->s_umount_key#60){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff888038a580d0 (&type->s_umount_key#60){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506 #1: ffffffff8ddd3798 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1444 2 locks held by syz-executor/7116: #0: ffff88805e7400d0 (&type->s_umount_key#60){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff88805e7400d0 (&type->s_umount_key#60){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff88805e7400d0 (&type->s_umount_key#60){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506 #1: ffffffff8ddd3798 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1444 2 locks held by syz-executor/7438: #0: ffff88803ccd80d0 (&type->s_umount_key#60){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff88803ccd80d0 (&type->s_umount_key#60){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff88803ccd80d0 (&type->s_umount_key#60){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506 #1: ffffffff8ddd3798 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1444 2 locks held by syz.6.216/7448: #0: ffff88805fe820d0 (&type->s_umount_key#58/1){+.+.}-{4:4}, at: alloc_super+0x204/0x990 fs/super.c:345 #1: ffffffff8ddd3798 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1444 1 lock held by syz.1.249/7628: #0: ffff88803327c0d0 (&type->s_umount_key#60){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff88803327c0d0 (&type->s_umount_key#60){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 1 lock held by syz.3.317/7974: #0: ffff88803327c0d0 (&type->s_umount_key#60){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff88803327c0d0 (&type->s_umount_key#60){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 1 lock held by syz.2.368/8125: #0: ffff8880233f60d0 (&type->s_umount_key#60){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff8880233f60d0 (&type->s_umount_key#60){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 1 lock held by syz-executor/8148: #0: ffffffff8ecd3178 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8ecd3178 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8ecd3178 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70 net/core/rtnetlink.c:4056 1 lock held by syz-executor/8295: #0: ffffffff8ecd3178 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8ecd3178 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0 net/ipv4/devinet.c:978 3 locks held by syz-executor/8308: #0: ffffffff8ed39180 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8ed38f78 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff8ed38f78 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff8ed38f78 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790 net/netlink/genetlink.c:1209 #2: ffffffff8ecd3178 (rtnl_mutex){+.+.}-{4:4}, at: wg_set_device+0x15b/0x1fe0 drivers/net/wireguard/netlink.c:514 2 locks held by syz-executor/8586: #0: ffffffff8f1d73e8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8f1d73e8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8f1d73e8 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8ecd3178 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8ecd3178 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8ecd3178 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70 net/core/rtnetlink.c:4056 1 lock held by syz-executor/8643: #0: ffffffff8ecd3178 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8ecd3178 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0 net/ipv4/devinet.c:978 3 locks held by syz.5.440/8646: ============================================= 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 07/12/2025 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:328 [inline] watchdog+0xf93/0xfe0 kernel/hung_task.c:491 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 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: 17 Comm: pr/legacy Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:400 Code: e8 6e 83 7f fc 44 89 f9 d3 e3 49 83 ee 80 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 5f bd de fc 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f c3 cc cc cc cc cc 44 89 f9 80 e1 07 RSP: 0018:ffffc90000167890 EFLAGS: 00000202 RAX: 1ffffffff3275600 RBX: 00000000000003fd RCX: 0000000000000000 RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffffff993ab850 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: ffffffff853edba0 R12: dffffc0000000000 R13: 0000000000000000 R14: ffffffff993ab5c0 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8881268bf000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000004200 CR3: 000000008d466000 CR4: 00000000003526f0 Call Trace: serial_in drivers/tty/serial/8250/8250.h:137 [inline] serial_lsr_in drivers/tty/serial/8250/8250.h:159 [inline] wait_for_lsr+0x1aa/0x2f0 drivers/tty/serial/8250/8250_port.c:1984 fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3288 [inline] serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3311 [inline] serial8250_console_write+0x11bd/0x1b40 drivers/tty/serial/8250/8250_port.c:3396 console_emit_next_record kernel/printk/printk.c:3118 [inline] console_flush_all+0x695/0xcd0 kernel/printk/printk.c:3226 __console_flush_and_unlock+0xa4/0x240 kernel/printk/printk.c:3285 legacy_kthread_func+0x13b/0x1a0 kernel/printk/printk.c:3638 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245