INFO: task syz.2.13738:12905 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.13738 state:D stack:22632 pid:12905 ppid:12580 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5380 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699 schedule+0xbd/0x170 kernel/sched/core.c:6773 perf_pending_task_sync kernel/events/core.c:5242 [inline] _free_event+0x174/0xf30 kernel/events/core.c:5248 put_event kernel/events/core.c:5376 [inline] perf_event_release_kernel+0x836/0x8c0 kernel/events/core.c:5501 perf_release+0x3b/0x40 kernel/events/core.c:5511 __fput+0x234/0x970 fs/file_table.c:384 task_work_run+0x1ce/0x250 kernel/task_work.c:239 get_signal+0x1235/0x1400 kernel/signal.c:2678 arch_do_signal_or_restart+0x9c/0x7b0 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xf6/0x180 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:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fa7dcf8f749 RSP: 002b:00007fa7ddefdfe8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038 RAX: fffffffffffffffc RBX: 00007fa7dd1e5fa0 RCX: 00007fa7dcf8f749 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000630c1000 RBP: 00007fa7dd013f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007fa7dd1e6038 R14: 00007fa7dd1e5fa0 R15: 00007ffd30a4d778 Showing all locks held in the system: 3 locks held by kworker/u4:1/12: #0: ffff88802bebd538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff88802bebd538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #1: ffffc90000117d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc90000117d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #2: ffffffff8dfbc5c8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xd0/0x14e0 net/ipv6/addrconf.c:4158 1 lock held by khungtaskd/29: #0: ffffffff8cd2fee0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8cd2fee0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8cd2fee0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633 2 locks held by getty/5550: #0: ffff8880311620a0 (&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+0x425/0x1380 drivers/tty/n_tty.c:2217 3 locks held by kworker/u4:7/24773: #0: ffff888017871538 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff888017871538 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #1: ffffc900043e7d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc900043e7d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #2: ffffffff8dfbc5c8 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:286 4 locks held by kworker/u4:15/24786: #0: ffff888017873938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff888017873938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #1: ffffc900044ffd00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc900044ffd00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #2: ffffffff8dfaf790 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x136/0xb90 net/core/net_namespace.c:606 #3: ffffffff8dfbc5c8 (rtnl_mutex){+.+.}-{3:3}, at: ip_tunnel_delete_nets+0xcc/0x360 net/ipv4/ip_tunnel.c:1152 2 locks held by kworker/0:9/10909: #0: ffff888017872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff888017872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #1: ffffc90005197d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc90005197d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 2 locks held by syz.1.14127/14124: #0: ffffffff8dfbc5c8 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline] #0: ffffffff8dfbc5c8 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x41/0x1c0 drivers/net/tun.c:3511 #1: ffffffff8cd358b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:292 [inline] #1: ffffffff8cd358b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x448/0x830 kernel/rcu/tree_exp.h:1004 1 lock held by syz.0.14129/14129: #0: ffffffff8dfbc5c8 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline] #0: ffffffff8dfbc5c8 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x41/0x1c0 drivers/net/tun.c:3511 1 lock held by syz.8.14131/14132: #0: ffffffff8dfbc5c8 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline] #0: ffffffff8dfbc5c8 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x41/0x1c0 drivers/net/tun.c:3511 1 lock held by syz.4.14132/14135: #0: ffffffff8dfbc5c8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline] #0: ffffffff8dfbc5c8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x76f/0xf10 net/core/rtnetlink.c:6469 ============================================= 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 10/02/2025 Call Trace: dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106 nmi_cpu_backtrace+0x39b/0x3d0 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+0xf41/0xf80 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: 14131 Comm: syz.0.14129 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:__sanitizer_cov_trace_pc+0x45/0x60 kernel/kcov.c:221 Code: ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 1c 16 00 00 00 74 2c 8b 91 f8 15 00 00 83 fa 02 75 21 48 8b 91 00 16 00 00 48 8b 32 <48> 8d 7e 01 8b 89 fc 15 00 00 48 39 cf 73 08 48 89 3a 48 89 44 f2 RSP: 0018:ffffc9000494edb8 EFLAGS: 00000246 RAX: ffffffff8197a181 RBX: 0000000000000000 RCX: ffff888020db9e00 RDX: ffffc9000ce5a000 RSI: 000000000007ffff RDI: 0000000000000001 RBP: 00000000000014f4 R08: ffff888020db9e00 R09: 0000000000000005 R10: 0000000000000006 R11: 0000000000000002 R12: ffff888067118570 R13: dffffc0000000000 R14: ffff88802f678000 R15: 000000000000002a FS: 00007f336647e6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b30d22ff8 CR3: 000000002efed000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000200000000300 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: mark_all_scalars_precise+0x371/0x5e0 kernel/bpf/verifier.c:4034 __mark_chain_precision+0x682a/0x7510 kernel/bpf/verifier.c:4355 mark_chain_precision kernel/bpf/verifier.c:4467 [inline] check_cond_jmp_op+0x39f/0x2680 kernel/bpf/verifier.c:14601 do_check+0x672e/0xdbe0 kernel/bpf/verifier.c:17360 do_check_common+0xadb/0x13e0 kernel/bpf/verifier.c:19706 do_check_main kernel/bpf/verifier.c:19769 [inline] bpf_check+0x649f/0xe970 kernel/bpf/verifier.c:20437 bpf_prog_load+0x11cb/0x16d0 kernel/bpf/syscall.c:2750 __sys_bpf+0x55a/0x800 kernel/bpf/syscall.c:5473 __do_sys_bpf kernel/bpf/syscall.c:5577 [inline] __se_sys_bpf kernel/bpf/syscall.c:5575 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5575 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f336558f749 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f336647e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f33657e5fa0 RCX: 00007f336558f749 RDX: 0000000000000048 RSI: 00002000000017c0 RDI: 0000000000000005 RBP: 00007f3365613f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f33657e6038 R14: 00007f33657e5fa0 R15: 00007ffcdbc62af8