INFO: task syz-executor:5812 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:22392 pid:5812 tgid:5812 ppid:1 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x14de/0x5210 kernel/sched/core.c:6907 __schedule_loop kernel/sched/core.c:6989 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7285 rt_mutex_slowlock_block+0x508/0x680 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+0x2dc/0x710 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] __mutex_lock_common kernel/locking/rtmutex_api.c:534 [inline] mutex_lock_nested+0x168/0x1d0 kernel/locking/rtmutex_api.c:552 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+0x13d/0x2d0 fs/super.c:646 kill_block_super+0x44/0x90 fs/super.c:1725 deactivate_locked_super+0xbc/0x130 fs/super.c:476 cleanup_mnt+0x437/0x4d0 fs/namespace.c:1312 task_work_run+0x1d9/0x270 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:67 [inline] exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline] do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff10950d1d7 RSP: 002b:00007fff326443a8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007ff1095a1c3b RCX: 00007ff10950d1d7 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fff32644460 RBP: 00007fff32644460 R08: 00007fff32645460 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff326454f0 R13: 00007ff1095a1c3b R14: 000000000002fc5e R15: 00007fff32645530 INFO: task syz-executor:7603 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:22648 pid:7603 tgid:7603 ppid:1 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x14de/0x5210 kernel/sched/core.c:6907 __schedule_loop kernel/sched/core.c:6989 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7285 rt_mutex_slowlock_block+0x508/0x680 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+0x2dc/0x710 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] __mutex_lock_common kernel/locking/rtmutex_api.c:534 [inline] mutex_lock_nested+0x168/0x1d0 kernel/locking/rtmutex_api.c:552 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+0x13d/0x2d0 fs/super.c:646 kill_block_super+0x44/0x90 fs/super.c:1725 deactivate_locked_super+0xbc/0x130 fs/super.c:476 cleanup_mnt+0x437/0x4d0 fs/namespace.c:1312 task_work_run+0x1d9/0x270 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:67 [inline] exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline] do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1c3639d1d7 RSP: 002b:00007ffc0c743138 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f1c36431c3b RCX: 00007f1c3639d1d7 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc0c7431f0 RBP: 00007ffc0c7431f0 R08: 00007ffc0c7441f0 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffc0c744280 R13: 00007f1c36431c3b R14: 000000000003b0da R15: 00007ffc0c7442c0 Showing all locks held in the system: 4 locks held by pr/legacy/17: 1 lock held by khungtaskd/37: #0: ffffffff8dbcd480 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8dbcd480 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8dbcd480 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 3 locks held by kworker/u8:9/1439: #0: ffff88813fe74138 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline] #0: ffff88813fe74138 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3358 #1: ffffc90005287c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #1: ffffc90005287c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3358 #2: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313 3 locks held by kworker/u8:14/1557: #0: ffff888032323138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline] #0: ffff888032323138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3358 #1: ffffc900056a7c40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #1: ffffc900056a7c40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3358 #2: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x124/0x1680 net/ipv6/addrconf.c:4194 2 locks held by getty/5560: #0: ffff8880378600a0 (&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 2 locks held by syz-executor/5812: #0: ffff88805ebf40d0 (&type->s_umount_key#63){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff88805ebf40d0 (&type->s_umount_key#63){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff88805ebf40d0 (&type->s_umount_key#63){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508 #1: ffffffff8e0467f8 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443 2 locks held by syz-executor/6134: #0: ffff88803d3140d0 (&type->s_umount_key#63){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff88803d3140d0 (&type->s_umount_key#63){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff88803d3140d0 (&type->s_umount_key#63){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508 #1: ffffffff8e0467f8 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443 2 locks held by syz-executor/7201: #0: ffff88803ad760d0 (&type->s_umount_key#63){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff88803ad760d0 (&type->s_umount_key#63){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff88803ad760d0 (&type->s_umount_key#63){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508 #1: ffffffff8e0467f8 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443 2 locks held by syz-executor/7495: #0: ffff88804ce520d0 (&type->s_umount_key#63){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff88804ce520d0 (&type->s_umount_key#63){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff88804ce520d0 (&type->s_umount_key#63){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508 #1: ffffffff8e0467f8 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443 2 locks held by syz-executor/7603: #0: ffff8880376f20d0 (&type->s_umount_key#63){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff8880376f20d0 (&type->s_umount_key#63){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff8880376f20d0 (&type->s_umount_key#63){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508 #1: ffffffff8e0467f8 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443 2 locks held by syz-executor/7705: #0: ffff888010ff20d0 (&type->s_umount_key#63){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff888010ff20d0 (&type->s_umount_key#63){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff888010ff20d0 (&type->s_umount_key#63){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508 #1: ffffffff8e0467f8 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443 2 locks held by syz.8.334/8807: #0: ffff8880368740d0 (&type->s_umount_key#62/1){+.+.}-{4:4}, at: alloc_super+0x28c/0xac0 fs/super.c:345 #1: ffffffff8e0467f8 (jfs_log_mutex){+.+.}-{4:4}, at: open_dummy_log fs/jfs/jfs_logmgr.c:1191 [inline] #1: ffffffff8e0467f8 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogOpen+0x1a1/0xfa0 fs/jfs/jfs_logmgr.c:1066 1 lock held by syz.3.347/8879: #0: ffff88805ebf40d0 (&type->s_umount_key#63){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff88805ebf40d0 (&type->s_umount_key#63){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 2 locks held by syz-executor/9074: #0: ffff8880606640d0 (&type->s_umount_key#63){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff8880606640d0 (&type->s_umount_key#63){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff8880606640d0 (&type->s_umount_key#63){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508 #1: ffffffff8e0467f8 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443 1 lock held by syz.4.350/9297: #0: ffff88803d3140d0 (&type->s_umount_key#63){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff88803d3140d0 (&type->s_umount_key#63){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 1 lock held by syz.7.374/9415: #0: ffff88803ad760d0 (&type->s_umount_key#63){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff88803ad760d0 (&type->s_umount_key#63){++++}-{4:4}, at: super_lock+0x289/0x3d0 fs/super.c:122 1 lock held by syz.2.376/9428: #0: ffff8880376f20d0 (&type->s_umount_key#63){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff8880376f20d0 (&type->s_umount_key#63){++++}-{4:4}, at: super_lock+0x289/0x3d0 fs/super.c:122 1 lock held by syz.9.377/9431: #0: ffff88804ce520d0 (&type->s_umount_key#63){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff88804ce520d0 (&type->s_umount_key#63){++++}-{4:4}, at: super_lock+0x289/0x3d0 fs/super.c:122 1 lock held by syz-executor/9562: #0: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: inet6_rtm_newaddr+0x65f/0xe30 net/ipv6/addrconf.c:5027 1 lock held by syz-executor/9569: #0: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a1/0x1be0 net/core/rtnetlink.c:4071 2 locks held by syz-executor/9570: #0: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a1/0x1be0 net/core/rtnetlink.c:4071 #1: ffff888066f9ce98 (&dev_instance_lock_key#24){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2781 [inline] #1: ffff888066f9ce98 (&dev_instance_lock_key#24){+.+.}-{4:4}, at: netdev_lock_ops include/net/netdev_lock.h:42 [inline] #1: ffff888066f9ce98 (&dev_instance_lock_key#24){+.+.}-{4:4}, at: do_setlink+0x3d2/0x4590 net/core/rtnetlink.c:3068 3 locks held by udevd/9679: 6 locks held by syz-executor/9681: 1 lock held by cmp/9823: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 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+0xf90/0xfe0 kernel/hung_task.c:515 kthread+0x388/0x470 kernel/kthread.c:467 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: 17 Comm: pr/legacy Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:400 Code: e8 4e 38 9d 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 9f 51 02 fd 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:ffffc900001679d0 EFLAGS: 00000202 RAX: 1ffffffff32df200 RBX: 00000000000003fd RCX: 0000000000000000 RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffffff996f9930 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: ffffffff8525dce0 R12: dffffc0000000000 R13: 0000000000000000 R14: ffffffff996f96a0 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888126595000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fbb0e8a9000 CR3: 0000000024ada000 CR4: 00000000003526f0 Call Trace: serial_in drivers/tty/serial/8250/8250.h:128 [inline] serial_lsr_in drivers/tty/serial/8250/8250.h:150 [inline] wait_for_lsr+0x1aa/0x2f0 drivers/tty/serial/8250/8250_port.c:1961 fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3234 [inline] serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3257 [inline] serial8250_console_write+0x120d/0x1b90 drivers/tty/serial/8250/8250_port.c:3342 console_emit_next_record kernel/printk/printk.c:3111 [inline] console_flush_one_record+0x68b/0xb90 kernel/printk/printk.c:3217 legacy_kthread_func+0x1b6/0x250 kernel/printk/printk.c:3676 kthread+0x388/0x470 kernel/kthread.c:467 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245