INFO: task syz.3.1900:12577 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.1900 state:D stack:26192 pid:12577 ppid:6844 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5245 [inline] __schedule+0x11d1/0x40e0 kernel/sched/core.c:6562 schedule+0xb9/0x180 kernel/sched/core.c:6638 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6697 rwsem_down_read_slowpath+0x516/0x870 kernel/locking/rwsem.c:1094 __down_read_common kernel/locking/rwsem.c:1261 [inline] __down_read kernel/locking/rwsem.c:1274 [inline] down_read+0x94/0x2d0 kernel/locking/rwsem.c:1522 iterate_supers+0xa4/0x1d0 fs/super.c:755 ksys_sync+0x9d/0x170 fs/sync.c:102 __ia32_sys_sync+0xa/0x10 fs/sync.c:113 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f8c85f9c819 RSP: 002b:00007f8c86dd7028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007f8c86215fa0 RCX: 00007f8c85f9c819 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f8c86215fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f8c86216038 R14: 00007f8c86215fa0 R15: 00007ffe08aac948 INFO: task syz.8.1977:12832 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.8.1977 state:D stack:27856 pid:12832 ppid:5979 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5245 [inline] __schedule+0x11d1/0x40e0 kernel/sched/core.c:6562 schedule+0xb9/0x180 kernel/sched/core.c:6638 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6697 rwsem_down_read_slowpath+0x516/0x870 kernel/locking/rwsem.c:1094 __down_read_common kernel/locking/rwsem.c:1261 [inline] __down_read kernel/locking/rwsem.c:1274 [inline] down_read+0x94/0x2d0 kernel/locking/rwsem.c:1522 iterate_supers+0xa4/0x1d0 fs/super.c:755 ksys_sync+0x9d/0x170 fs/sync.c:102 __ia32_sys_sync+0xa/0x10 fs/sync.c:113 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fac29f9c819 RSP: 002b:00007fac281f6028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007fac2a215fa0 RCX: 00007fac29f9c819 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fac2a215fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fac2a216038 R14: 00007fac2a215fa0 R15: 00007ffc5bb6d258 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8cb2df70 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 1 lock held by rcu_tasks_trace/13: #0: ffffffff8cb2e790 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 3 locks held by kworker/0:1/14: #0: ffff88802f061d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267 #1: ffffc90000137d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267 #2: ffffffff8dd47f68 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xca/0x14f0 net/ipv6/addrconf.c:4131 1 lock held by khungtaskd/28: #0: ffffffff8cb2d5e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] ffffffff8cb2d5e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] ffffffff8cb2d5e0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513 1 lock held by dhcpcd/3931: #0: ffffffff8dd47f68 (rtnl_mutex){+.+.}-{3:3}, at: __netlink_dump_start+0x11f/0x6f0 net/netlink/af_netlink.c:2305 2 locks held by getty/4027: #0: ffff88802f8ef098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x429/0x1390 drivers/tty/n_tty.c:2198 2 locks held by kworker/u4:10/4472: #0: ffff8880b8e3ab18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xa5/0x140 kernel/sched/core.c:546 #1: ffff8880b8e27888 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x398/0x6d0 kernel/sched/psi.c:999 2 locks held by kworker/u4:21/9085: 1 lock held by syz.9.1368/10601: 1 lock held by syz.3.1900/12577: #0: ffff88807604c0e0 (&type->s_umount_key#127){.+.+}-{3:3}, at: iterate_supers+0xa4/0x1d0 fs/super.c:755 1 lock held by syz.8.1977/12832: #0: ffff88807604c0e0 (&type->s_umount_key#127){.+.+}-{3:3}, at: iterate_supers+0xa4/0x1d0 fs/super.c:755 3 locks held by kworker/1:20/13370: #0: ffff88802f061d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267 #1: ffffc9000c80fd00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267 #2: ffffffff8dd47f68 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xca/0x14f0 net/ipv6/addrconf.c:4131 1 lock held by syz.6.2099/13412: #0: ffff88807604c0e0 (&type->s_umount_key#127){.+.+}-{3:3}, at: iterate_supers+0xa4/0x1d0 fs/super.c:755 1 lock held by syz.5.2279/14338: #0: ffff88807604c0e0 (&type->s_umount_key#127){.+.+}-{3:3}, at: iterate_supers+0xa4/0x1d0 fs/super.c:755 4 locks held by syz-executor/14498: 2 locks held by sed/14879: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 28 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Call Trace: dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106 nmi_cpu_backtrace+0x3e6/0x460 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline] watchdog+0xeee/0xf30 kernel/hung_task.c:377 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 13044 Comm: kworker/u4:26 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:35 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:70 [inline] RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:106 [inline] RIP: 0010:lock_release+0x15e/0x920 kernel/locking/lockdep.c:5678 Code: 04 00 00 4c 89 74 24 08 43 c6 44 2f 08 00 48 c7 84 24 a0 00 00 00 00 00 00 00 9c 8f 84 24 a0 00 00 00 48 8b 84 24 a0 00 00 00 <48> 89 44 24 50 43 c6 44 2f 08 f8 fa 48 c7 c7 00 1e 8c 8a e8 da 4a RSP: 0018:ffffc90000007900 EFLAGS: 00000046 RAX: 0000000000000046 RBX: ffff8880646ec65c RCX: 513cfb47875bd300 RDX: 0000000000000000 RSI: ffffffff8adf1380 RDI: ffffffff8adf1340 RBP: ffffc90000007a20 R08: ffffffff8e1ff42f R09: 1ffffffff1c3fe85 R10: dffffc0000000000 R11: fffffbfff1c3fe86 R12: dffffc0000000000 R13: dffffc0000000000 R14: ffff8880646ebb80 R15: 1ffff92000000f2c FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fae00575fe8 CR3: 000000000c88e000 CR4: 00000000003506f0 DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000002 DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: rcu_lock_release include/linux/rcupdate.h:355 [inline] rcu_read_unlock_sched include/linux/rcupdate.h:904 [inline] pfn_valid include/linux/mmzone.h:1867 [inline] __virt_addr_valid+0x435/0x540 arch/x86/mm/physaddr.c:65 kasan_addr_to_slab+0x9/0xc0 mm/kasan/common.c:36 __kasan_record_aux_stack+0xf/0xc0 mm/kasan/generic.c:471 insert_work+0x54/0x3c0 kernel/workqueue.c:1361 __queue_work+0xba3/0xfb0 kernel/workqueue.c:1520 call_timer_fn+0x1ac/0x670 kernel/time/timer.c:1701 expire_timers kernel/time/timer.c:1747 [inline] __run_timers+0x569/0x800 kernel/time/timer.c:2023 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:2036 handle_softirqs+0x2a1/0x930 kernel/softirq.c:596 __do_softirq kernel/softirq.c:630 [inline] invoke_softirq kernel/softirq.c:470 [inline] __irq_exit_rcu+0x13b/0x230 kernel/softirq.c:679 irq_exit_rcu+0x5/0x20 kernel/softirq.c:691 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline] sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1118 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:csd_lock_wait kernel/smp.c:424 [inline] RIP: 0010:smp_call_function_many_cond+0xea2/0x1290 kernel/smp.c:998 Code: 00 00 00 41 8b 1f 89 de 83 e6 01 31 ff e8 e6 f6 0a 00 83 e3 01 48 bb 00 00 00 00 00 fc ff df 75 07 e8 72 f3 0a 00 eb 37 f3 90 <41> 0f b6 04 1c 84 c0 75 10 41 f7 07 01 00 00 00 74 1e e8 57 f3 0a RSP: 0018:ffffc90005057800 EFLAGS: 00000293 RAX: ffffffff817781f9 RBX: dffffc0000000000 RCX: ffff8880646ebb80 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90005057960 R08: ffffffff90af9247 R09: 1ffffffff215f248 R10: dffffc0000000000 R11: fffffbfff215f249 R12: 1ffff110171e81d9 R13: ffff8880b8e3bbc0 R14: 0000000000000001 R15: ffff8880b8f40ec8 on_each_cpu_cond_mask+0x3b/0x80 kernel/smp.c:1165 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:1574 [inline] text_poke_bp_batch+0x2b7/0x850 arch/x86/kernel/alternative.c:1774 text_poke_flush arch/x86/kernel/alternative.c:1965 [inline] text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1972 arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:146 static_key_enable_cpuslocked+0x11f/0x240 kernel/jump_label.c:207 static_key_enable+0x16/0x20 kernel/jump_label.c:220 toggle_allocation_gate+0xba/0x470 mm/kfence/core.c:821 process_one_work+0x8a2/0x1160 kernel/workqueue.c:2292 worker_thread+0xaa2/0x1270 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295