INFO: task syz.3.1937:12580 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.1937 state:D stack:24488 pid:12580 ppid:5771 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x1553/0x45a0 kernel/sched/core.c:6700 schedule+0xbd/0x170 kernel/sched/core.c:6774 perf_pending_task_sync kernel/events/core.c:5244 [inline] _free_event+0x174/0xf30 kernel/events/core.c:5250 put_event kernel/events/core.c:5378 [inline] perf_event_release_kernel+0x842/0x8d0 kernel/events/core.c:5503 perf_release+0x3b/0x40 kernel/events/core.c:5513 __fput+0x234/0x970 fs/file_table.c:384 task_work_run+0x1d4/0x260 kernel/task_work.c:245 exit_task_work include/linux/task_work.h:43 [inline] do_exit+0x95a/0x2460 kernel/exit.c:884 do_group_exit+0x21b/0x2d0 kernel/exit.c:1026 get_signal+0x12fc/0x13f0 kernel/signal.c:2902 arch_do_signal_or_restart+0xc2/0x800 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fab4fb9ce59 RSP: 002b:00007fab50b130e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: 0000000000000000 RBX: 00007fab4fe15fa8 RCX: 00007fab4fb9ce59 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fab4fe15fa8 RBP: 00007fab4fe15fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fab4fe16038 R14: 00007fff62d17c00 R15: 00007fff62d17ce8 Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8d132120 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8d132120 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8d132120 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633 2 locks held by getty/5524: #0: ffff88802d09f0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x433/0x1390 drivers/tty/n_tty.c:2217 3 locks held by kworker/u4:15/8816: #0: ffff888017c71538 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #0: ffff888017c71538 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730 #1: ffffc90003237d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #1: ffffc90003237d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730 #2: ffffffff8e3c4308 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:286 1 lock held by syz.5.2992/16425: 5 locks held by syz.2.3002/16445: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 29 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Call Trace: dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106 nmi_cpu_backtrace+0x3a6/0x3e0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xf3d/0xf80 kernel/hung_task.c:379 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 16445 Comm: syz.2.3002 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:arch_irqs_disabled_flags arch/x86/include/asm/irqflags.h:126 [inline] RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:133 [inline] RIP: 0010:lock_release+0x56d/0x8c0 kernel/locking/lockdep.c:5777 Code: ff ff ff 65 0f c1 05 1a d2 99 7e 83 f8 01 75 7f 43 c6 44 2f 04 00 48 c7 84 24 80 00 00 00 00 00 00 00 9c 8f 84 24 80 00 00 00 84 24 80 00 00 00 00 02 00 00 43 c6 44 2f 04 f8 75 70 f7 44 24 RSP: 0018:ffffc90000007860 EFLAGS: 00000046 RAX: 0000000000000001 RBX: 6d73fa8622f36fe0 RCX: ba0e7b02c648db00 RDX: 0000000000000003 RSI: ffffffff8acadd60 RDI: ffffffff8b1c9a20 RBP: ffffc90000007970 R08: ffffffff8e8b3aef R09: 1ffffffff1d1675d R10: dffffc0000000000 R11: fffffbfff1d1675e R12: ffff888023a48b58 R13: dffffc0000000000 R14: ffff888023a48ad0 R15: 1ffff92000000f18 FS: 00007f6bf58b86c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f70d93ea2f8 CR3: 000000007af4a000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000200000000300 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: rcu_lock_release include/linux/rcupdate.h:344 [inline] rcu_read_unlock include/linux/rcupdate.h:819 [inline] __perf_event_output kernel/events/core.c:7986 [inline] perf_event_output_forward+0x330/0x3e0 kernel/events/core.c:7995 __perf_event_overflow+0x447/0x630 kernel/events/core.c:9720 perf_event_overflow kernel/events/core.c:9741 [inline] perf_swevent_hrtimer+0x439/0x610 kernel/events/core.c:11230 __run_hrtimer kernel/time/hrtimer.c:1754 [inline] __hrtimer_run_queues+0x4e1/0xc40 kernel/time/hrtimer.c:1818 hrtimer_interrupt+0x3c9/0x9c0 kernel/time/hrtimer.c:1880 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1077 [inline] __sysvec_apic_timer_interrupt+0xfb/0x3b0 arch/x86/kernel/apic/apic.c:1094 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline] sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1088 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xc0/0x120 kernel/locking/spinlock.c:194 Code: c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 41 c6 04 07 f8 75 4b f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 eb 98 cb f6 65 8b 05 7c c0 72 75 85 c0 74 3c 48 c7 04 24 0e 36 RSP: 0018:ffffc90004136060 EFLAGS: 00000206 RAX: dffffc0000000004 RBX: 0000000000000a06 RCX: ba0e7b02c648db00 RDX: dffffc0000000000 RSI: ffffffff8acacbe0 RDI: 0000000000000001 RBP: ffffc900041360f8 R08: ffffffff911c952f R09: 1ffffffff22392a5 R10: dffffc0000000000 R11: fffffbfff22392a6 R12: dffffc0000000000 R13: ffff888020e90000 R14: ffffffff974f0948 R15: 1ffff92000826c0c __debug_check_no_obj_freed lib/debugobjects.c:999 [inline] debug_check_no_obj_freed+0x51f/0x540 lib/debugobjects.c:1020 free_pages_prepare mm/page_alloc.c:1187 [inline] free_unref_page_prepare+0x1da/0x8c0 mm/page_alloc.c:2365 free_unref_page+0x32/0x2e0 mm/page_alloc.c:2458 discard_slab mm/slub.c:2127 [inline] __unfreeze_partials+0x1cf/0x210 mm/slub.c:2667 put_cpu_partial+0x17c/0x250 mm/slub.c:2743 __slab_free+0x319/0x400 mm/slub.c:3700 qlink_free mm/kasan/quarantine.c:166 [inline] qlist_free_all+0x75/0xd0 mm/kasan/quarantine.c:185 kasan_quarantine_reduce+0x143/0x160 mm/kasan/quarantine.c:292 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:306 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook+0x6e/0x4b0 mm/slab.h:767 slab_alloc_node mm/slub.c:3495 [inline] __kmem_cache_alloc_node+0x13a/0x250 mm/slub.c:3534 kmalloc_trace+0x2a/0xe0 mm/slab_common.c:1098 kmalloc include/linux/slab.h:600 [inline] kzalloc include/linux/slab.h:721 [inline] mld_add_delrec net/ipv6/mcast.c:742 [inline] igmp6_leave_group net/ipv6/mcast.c:2628 [inline] igmp6_group_dropped+0x395/0xd30 net/ipv6/mcast.c:722 __ipv6_dev_mc_dec+0x2b3/0x330 net/ipv6/mcast.c:977 addrconf_leave_solict net/ipv6/addrconf.c:2225 [inline] __ipv6_ifa_notify+0x457/0xb40 net/ipv6/addrconf.c:6290 addrconf_ifdown+0xe78/0x18c0 net/ipv6/addrconf.c:3967 addrconf_notify+0x6c6/0x1010 net/ipv6/addrconf.c:-1 notifier_call_chain+0x197/0x380 kernel/notifier.c:93 call_netdevice_notifiers_extack net/core/dev.c:2077 [inline] call_netdevice_notifiers net/core/dev.c:2091 [inline] __dev_notify_flags+0x16e/0x310 net/core/dev.c:8764 dev_change_flags+0xe8/0x1a0 net/core/dev.c:8800 do_setlink+0xc58/0x4130 net/core/rtnetlink.c:2909 __rtnl_newlink net/core/rtnetlink.c:3707 [inline] rtnl_newlink+0x17da/0x20a0 net/core/rtnetlink.c:3754 rtnetlink_rcv_msg+0x869/0xfa0 net/core/rtnetlink.c:6476 netlink_rcv_skb+0x241/0x4d0 net/netlink/af_netlink.c:2545 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x751/0x8d0 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x8d0/0xbf0 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] ____sys_sendmsg+0x5ba/0x960 net/socket.c:2594 ___sys_sendmsg+0x2a6/0x360 net/socket.c:2648 __sys_sendmsg net/socket.c:2677 [inline] __do_sys_sendmsg net/socket.c:2686 [inline] __se_sys_sendmsg+0x1c2/0x2b0 net/socket.c:2684 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f6bf499ce59 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f6bf58b8028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f6bf4c16090 RCX: 00007f6bf499ce59 RDX: 0000000000000000 RSI: 0000200000000040 RDI: 000000000000000b RBP: 00007f6bf4a32d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f6bf4c16128 R14: 00007f6bf4c16090 R15: 00007fff9cafa6c8