INFO: task syz.2.3027:20901 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.3027 state:D stack:26224 pid:20901 ppid: 19530 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 perf_pending_task_sync+0x13c/0x1c0 kernel/events/core.c:5127 _free_event+0x34/0xe60 kernel/events/core.c:5133 put_event kernel/events/core.c:5258 [inline] perf_event_release_kernel+0x83e/0x8d0 kernel/events/core.c:5383 perf_release+0x37/0x40 kernel/events/core.c:5393 __fput+0x234/0x930 fs/file_table.c:311 task_work_run+0x125/0x1a0 kernel/task_work.c:188 exit_task_work include/linux/task_work.h:33 [inline] do_exit+0x626/0x20c0 kernel/exit.c:883 do_group_exit+0x12e/0x300 kernel/exit.c:997 get_signal+0x6ca/0x12c0 kernel/signal.c:2900 arch_do_signal_or_restart+0xe7/0x12c0 arch/x86/kernel/signal.c:867 handle_signal_work kernel/entry/common.c:154 [inline] exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fe934ce1f79 RSP: 002b:00007fe932f1b028 EFLAGS: 00000246 ORIG_RAX: 000000000000012a RAX: 0000000000000007 RBX: 00007fe934f5c090 RCX: 00007fe934ce1f79 RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 00002000000000c0 RBP: 00007fe934d787e0 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000 R13: 00007fe934f5c128 R14: 00007fe934f5c090 R15: 00007ffee22ecb08 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8c31eaa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by getty/3949: #0: ffff88802ccbe098 (&tty->ldisc_sem){++++}-{0:0} , at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc900026562e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5df/0x1a70 drivers/tty/n_tty.c:2158 4 locks held by kworker/u4:6/4279: #0: ffff888016dcd938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc90004c1fd00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 #2: ffffffff8d430850 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x148/0xba0 net/core/net_namespace.c:589 #3: ffffffff8d43c748 (rtnl_mutex){+.+.}-{3:3}, at: ieee80211_unregister_hw+0x4d/0x220 net/mac80211/main.c:1392 3 locks held by kworker/u4:18/6486: 2 locks held by kworker/1:12/6786: #0: ffff8880b913a358 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475 #1: ffffffff8c31eaa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x9/0x30 include/linux/rcupdate.h:313 3 locks held by kworker/0:24/8317: #0: ffff88802b561d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc90003d6fd00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 #2: ffffffff8d43c748 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xca/0x1540 net/ipv6/addrconf.c:4110 2 locks held by kworker/0:30/8325: #0: ffff888016c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc90003edfd00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 3 locks held by kworker/1:37/12893: #0: ffff88802b561d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc9000339fd00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 #2: ffffffff8d43c748 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xca/0x1540 net/ipv6/addrconf.c:4110 3 locks held by kworker/u4:0/19594: 3 locks held by kworker/u4:8/21273: #0: ffff888016c79138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc90003a3fd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 #2: ffffffff8d43c748 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xa/0x50 net/core/link_watch.c:251 2 locks held by dhcpcd/21748: #0: ffff88807422a010 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline] #0: ffff88807422a010 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: __sock_release net/socket.c:650 [inline] #0: ffff88807422a010 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: sock_close+0x90/0x240 net/socket.c:1345 #1: ffffffff8c323528 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline] #1: ffffffff8c323528 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3a5/0x750 kernel/rcu/tree_exp.h:845 3 locks held by syz-executor/24861: #0: ffffffff8d4990f0 (cb_lock){++++}-{3:3}, at: genl_rcv+0x15/0x40 net/netlink/genetlink.c:802 #1: ffffffff8d498f48 (genl_mutex){+.+.}-{3:3}, at: genl_lock net/netlink/genetlink.c:33 [inline] #1: ffffffff8d498f48 (genl_mutex){+.+.}-{3:3}, at: genl_rcv_msg+0x161/0xf90 net/netlink/genetlink.c:790 #2: ffffffff8d43c748 (rtnl_mutex){+.+.}-{3:3}, at: ieee80211_register_hw+0x2ad3/0x3af0 net/mac80211/main.c:1315 1 lock held by syz-executor/24881: #0: ffffffff8d43c748 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline] #0: ffffffff8d43c748 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7ee/0xf30 net/core/rtnetlink.c:5681 4 locks held by syz.5.3878/25361: 2 locks held by syz.6.3883/25381: #0: ffffffff8c36c168 (event_mutex){+.+.}-{3:3}, at: perf_trace_destroy+0x2a/0x140 kernel/trace/trace_event_perf.c:239 #1: ffffffff8c323528 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline] #1: ffffffff8c323528 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3a5/0x750 kernel/rcu/tree_exp.h:845 1 lock held by syz.7.3886/25397: #0: ffffffff8d43c748 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:699 [inline] #0: ffffffff8d43c748 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3d/0x1b0 drivers/net/tun.c:3440 1 lock held by syz.5.3887/25405: #0: ffffffff8d43c748 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:699 [inline] #0: ffffffff8d43c748 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3d/0x1b0 drivers/net/tun.c:3440 1 lock held by dhcpcd/25417: #0: ffff88805f23e210 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline] #0: ffff88805f23e210 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: __sock_release net/socket.c:650 [inline] #0: ffff88805f23e210 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: sock_close+0x90/0x240 net/socket.c:1345 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 27 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline] watchdog+0xe0f/0xe50 kernel/hung_task.c:369 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 25361 Comm: syz.5.3878 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:ip6t_do_table+0xbb0/0x14d0 net/ipv6/netfilter/ip6_tables.c:323 Code: 0f b6 04 28 84 c0 0f 85 b4 05 00 00 45 8b 36 48 8d 7b 08 48 89 f8 48 c1 e8 03 42 80 3c 28 00 74 05 e8 44 55 0c f9 4c 01 73 08 <48> 89 d8 48 c1 e8 03 42 80 3c 28 00 74 08 48 89 df e8 2a 55 0c f9 RSP: 0018:ffffc90000007600 EFLAGS: 00000216 RAX: 1ffffd1ffff41a07 RBX: ffffe8ffffa0d030 RCX: ffff888078209dc0 RDX: 0000000000000100 RSI: 0000000000000000 RDI: ffffe8ffffa0d038 RBP: ffffc900000077f0 R08: ffffc9000000776f R09: ffffc90000007750 R10: dffffc0000000000 R11: fffff52000000eee R12: 1ffff1100fa1b867 R13: dffffc0000000000 R14: 0000000000000048 R15: ffff88807d0dc2b0 FS: 0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fbd752d1198 CR3: 0000000078510000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: ip6t_mangle_out net/ipv6/netfilter/ip6table_mangle.c:49 [inline] ip6table_mangle_hook+0x214/0x7a0 net/ipv6/netfilter/ip6table_mangle.c:71 nf_hook_entry_hookfn include/linux/netfilter.h:142 [inline] nf_hook_slow+0xb9/0x200 net/netfilter/core.c:584 nf_hook include/linux/netfilter.h:257 [inline] NF_HOOK include/linux/netfilter.h:300 [inline] ndisc_send_skb+0x1397/0x1500 net/ipv6/ndisc.c:513 addrconf_rs_timer+0x2d1/0x630 net/ipv6/addrconf.c:3956 call_timer_fn+0x17b/0x540 kernel/time/timer.c:1648 expire_timers kernel/time/timer.c:1699 [inline] __run_timers+0x53e/0x800 kernel/time/timer.c:1970 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1983 handle_softirqs+0x339/0x830 kernel/softirq.c:576 __do_softirq kernel/softirq.c:610 [inline] invoke_softirq kernel/softirq.c:450 [inline] __irq_exit_rcu+0x13b/0x230 kernel/softirq.c:659 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:_raw_spin_lock_irq+0x1/0xf0 kernel/locking/spinlock.c:169 Code: 44 24 48 75 10 4c 89 f0 48 8d 65 e0 5b 41 5c 41 5e 41 5f 5d c3 e8 1f 93 f6 ff 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 <48> 89 e5 41 57 41 56 53 48 83 e4 e0 48 83 ec 60 48 89 fb 65 48 8b RSP: 0018:ffffc90003b5ed30 EFLAGS: 00000246 RAX: ffffffffffffffff RBX: 0000000000000000 RCX: ffff888078209dc0 RDX: 0000000000000000 RSI: ffffffff8a2b3a20 RDI: ffff88807c1c9c38 RBP: ffffc90003b5eea0 R08: ffffffff8d89db2f R09: 1ffffffff1b13b65 R10: dffffc0000000000 R11: fffffbfff1b13b66 R12: ffffc90003b5ede0 R13: dffffc0000000000 R14: 0000000000000cc0 R15: ffffea00012adb80 spin_lock_irq include/linux/spinlock.h:389 [inline] shmem_add_to_page_cache+0xbb6/0x14d0 mm/shmem.c:731 shmem_getpage_gfp+0x1796/0x2d40 mm/shmem.c:1940 shmem_getpage mm/shmem.c:151 [inline] shmem_write_begin+0xcd/0x1a0 mm/shmem.c:2474 generic_perform_write+0x2b6/0x550 mm/filemap.c:3785 __generic_file_write_iter+0x25f/0x4e0 mm/filemap.c:3912 generic_file_write_iter+0xa6/0x1b0 mm/filemap.c:3944 __kernel_write+0x51c/0x970 fs/read_write.c:539 __dump_emit+0x249/0x370 fs/coredump.c:943 dump_user_range+0x84/0x340 fs/coredump.c:1017 elf_core_dump+0x2fbd/0x3500 fs/binfmt_elf.c:2285 do_coredump+0x14c7/0x2ac0 fs/coredump.c:894 get_signal+0x40a/0x12c0 kernel/signal.c:2886 arch_do_signal_or_restart+0xe7/0x12c0 arch/x86/kernel/signal.c:867 handle_signal_work kernel/entry/common.c:154 [inline] exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214 irqentry_exit_to_user_mode+0x5/0x30 kernel/entry/common.c:320 exc_page_fault+0x88/0x100 arch/x86/mm/fault.c:1499 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:606 RIP: 0033:0x7fc2797bd4f7 Code: e8 8e fa ff ff 89 f2 48 8d 3d 05 43 1b 00 48 8d 35 5f f9 1d 00 31 c0 e8 e7 f8 ff ff 0f 1f 80 00 00 00 00 53 89 fb 48 83 ec 10 <64> 8b 04 25 a4 ff ff ff 85 c0 74 2a 89 fe 31 c0 bf 3c 00 00 00 e8 RSP: 002b:00007fc277b42120 EFLAGS: 00010202 RAX: 0000000000000000 RBX: 000000000000000b RCX: 00007fc279906f79 RDX: 00007fc277b42140 RSI: 00007fc277b42270 RDI: 000000000000000b RBP: 00007fc27999d7e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007fc279b81038 R14: 00007fc279b80fa0 R15: 00007ffd97154c28