INFO: task syz-executor:7025 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:21536 pid:7025 tgid:7025 ppid:1 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+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+0x135/0x2c0 fs/super.c:643 kill_block_super+0x44/0x90 fs/super.c:1722 deactivate_locked_super+0xbc/0x130 fs/super.c:474 cleanup_mnt+0x437/0x4d0 fs/namespace.c:1318 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:44 [inline] exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:75 __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_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x2b7/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd04d7dbf17 RSP: 002b:00007fff5f944778 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007fd04d84471f RCX: 00007fd04d7dbf17 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fff5f944830 RBP: 00007fff5f944830 R08: 00007fff5f945830 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff5f9458c0 R13: 00007fd04d84471f R14: 000000000003b12f R15: 00007fff5f945900 INFO: task syz-executor:7267 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:21048 pid:7267 tgid:7267 ppid:1 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+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+0x135/0x2c0 fs/super.c:643 kill_block_super+0x44/0x90 fs/super.c:1722 deactivate_locked_super+0xbc/0x130 fs/super.c:474 cleanup_mnt+0x437/0x4d0 fs/namespace.c:1318 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:44 [inline] exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:75 __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_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x2b7/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff6c6c1bf17 RSP: 002b:00007ffdf7463838 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007ff6c6c8471f RCX: 00007ff6c6c1bf17 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffdf74638f0 RBP: 00007ffdf74638f0 R08: 00007ffdf74648f0 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffdf7464980 R13: 00007ff6c6c8471f R14: 000000000003b5f3 R15: 00007ffdf74649c0 Showing all locks held in the system: 8 locks held by ktimers/0/16: 1 lock held by khungtaskd/38: #0: ffffffff8d9c7780 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8d9c7780 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8d9c7780 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 3 locks held by kworker/u8:7/1148: #0: ffff88813fe29938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88813fe29938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340 #1: ffffc90004abfbc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc90004abfbc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340 #2: ffffffff8ed37f78 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 1 lock held by dhcpcd/5466: #0: ffffffff8ed37f78 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8ed37f78 (rtnl_mutex){+.+.}-{4:4}, at: devinet_ioctl+0x32b/0x1b30 net/ipv4/devinet.c:1120 2 locks held by getty/5561: #0: ffff88814def30a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e8b2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13c0 drivers/tty/n_tty.c:2211 3 locks held by kworker/1:7/5974: #0: ffff88813fe15138 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88813fe15138 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340 #1: ffffc900054dfbc0 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc900054dfbc0 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340 #2: ffffffff8ed37f78 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104 2 locks held by syz-executor/7025: #0: ffff8880277a20d0 (&type->s_umount_key#79){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff8880277a20d0 (&type->s_umount_key#79){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff8880277a20d0 (&type->s_umount_key#79){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506 #1: ffffffff8de3e798 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443 2 locks held by syz-executor/7070: #0: ffff8880292be0d0 (&type->s_umount_key#79){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff8880292be0d0 (&type->s_umount_key#79){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff8880292be0d0 (&type->s_umount_key#79){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506 #1: ffffffff8de3e798 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443 2 locks held by syz-executor/7267: #0: ffff88802dc000d0 (&type->s_umount_key#79){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff88802dc000d0 (&type->s_umount_key#79){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff88802dc000d0 (&type->s_umount_key#79){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506 #1: ffffffff8de3e798 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443 2 locks held by syz-executor/7752: #0: ffff8880245000d0 (&type->s_umount_key#79){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff8880245000d0 (&type->s_umount_key#79){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff8880245000d0 (&type->s_umount_key#79){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506 #1: ffffffff8de3e798 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443 2 locks held by syz-executor/7979: #0: ffff88803ac0a0d0 (&type->s_umount_key#79){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff88803ac0a0d0 (&type->s_umount_key#79){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff88803ac0a0d0 (&type->s_umount_key#79){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506 #1: ffffffff8de3e798 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443 1 lock held by syz-executor/8013: #0: ffff8880642900d0 (&type->s_umount_key#79){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff8880642900d0 (&type->s_umount_key#79){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff8880642900d0 (&type->s_umount_key#79){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506 4 locks held by kworker/u8:35/9191: #0: ffff88801aa94938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88801aa94938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340 #1: ffffc90005c6fbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc90005c6fbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340 #2: ffffffff8ed295e0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xfe/0x7b0 net/core/net_namespace.c:670 #3: ffffffff8ed37f78 (rtnl_mutex){+.+.}-{4:4}, at: ops_exit_rtnl_list net/core/net_namespace.c:173 [inline] #3: ffffffff8ed37f78 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x2a4/0x940 net/core/net_namespace.c:248 7 locks held by syz-executor/10027: #0: ffff888035a20480 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2681 [inline] #0: ffff888035a20480 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x22d/0xba0 fs/read_write.c:682 #1: ffff8880809dfc78 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343 #2: ffff8880278e2878 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff8880278e2878 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344 #3: ffffffff8e5a8ef8 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: new_device_store+0x13c/0x710 drivers/net/netdevsim/bus.c:184 #4: ffff88805edba0d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #4: ffff88805edba0d8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1006 #5: ffff888031a2c300 (&devlink->lock_key#19){+.+.}-{4:4}, at: nsim_drv_probe+0xc9/0xc30 drivers/net/netdevsim/dev.c:1637 #6: ffffffff8ed37f78 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #6: ffffffff8ed37f78 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_dev_lock+0x257/0x2f0 net/core/dev.c:2156 1 lock held by syz.6.554/10088: #0: ffff8880292be0d0 (&type->s_umount_key#79){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff8880292be0d0 (&type->s_umount_key#79){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:121 1 lock held by syz.7.576/10205: #0: ffff8880292be0d0 (&type->s_umount_key#79){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff8880292be0d0 (&type->s_umount_key#79){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:121 1 lock held by syz.7.576/10207: #0: ffff8880292be0d0 (&type->s_umount_key#79){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff8880292be0d0 (&type->s_umount_key#79){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:121 ============================================= 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 01/13/2026 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+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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 16 Comm: ktimers/0 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/13/2026 RIP: 0010:kasan_check_range+0x5/0x2c0 mm/kasan/generic.c:199 Code: 48 c7 c6 8f 7f 39 8d e8 99 52 03 ff 90 0f 0b cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 40 d6 55 <41> 57 41 56 41 55 41 54 53 b0 01 48 85 f6 0f 84 ae 01 00 00 4c 8d RSP: 0018:ffffc90000157188 EFLAGS: 00000246 RAX: ffffc900001573c0 RBX: 0000000000000010 RCX: ffffffff8174bebe RDX: 0000000000000001 RSI: 0000000000000010 RDI: ffffc900001572d8 RBP: 0000000000000000 R08: 000000000000000c R09: ffffffff8d9c7780 R10: ffffc900001572d8 R11: ffffffff81ad1370 R12: ffffc900001572d8 R13: 1ffff9200002ae53 R14: ffffc900001572d8 R15: ffffc900001572d0 FS: 0000000000000000(0000) GS:ffff8881267fc000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0174803000 CR3: 0000000030c9e000 CR4: 00000000003526f0 Call Trace: __asan_memset+0x22/0x50 mm/kasan/shadow.c:84 unwind_next_frame+0xeae/0x23c0 arch/x86/kernel/unwind_orc.c:607 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 ref_tracker_alloc+0x1ba/0x4b0 lib/ref_tracker.c:277 __netdev_tracker_alloc include/linux/netdevice.h:4400 [inline] netdev_hold include/linux/netdevice.h:4429 [inline] ___neigh_create+0xd17/0x2330 net/core/neighbour.c:665 ip6_finish_output2+0x1082/0x13c0 net/ipv6/ip6_output.c:128 NF_HOOK_COND include/linux/netfilter.h:307 [inline] ip6_output+0x340/0x550 net/ipv6/ip6_output.c:247 NF_HOOK include/linux/netfilter.h:318 [inline] ndisc_send_skb+0xbaa/0x14e0 net/ipv6/ndisc.c:512 addrconf_rs_timer+0x395/0x6d0 net/ipv6/addrconf.c:4037 call_timer_fn+0x192/0x5a0 kernel/time/timer.c:1748 expire_timers kernel/time/timer.c:1799 [inline] __run_timers kernel/time/timer.c:2373 [inline] __run_timer_base+0x6a3/0x9f0 kernel/time/timer.c:2385 run_timer_base kernel/time/timer.c:2394 [inline] run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2404 handle_softirqs+0x1de/0x640 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] run_ktimerd+0x69/0x100 kernel/softirq.c:1138 smpboot_thread_fn+0x541/0xa50 kernel/smpboot.c:160 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