INFO: task syz.8.4258:21572 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.8.4258 state:D stack:23312 pid:21572 ppid: 19226 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11c3/0x4350 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+0x34/0xe30 kernel/events/core.c:5133 put_event kernel/events/core.c:5258 [inline] perf_event_release_kernel+0x7c4/0x850 kernel/events/core.c:5383 perf_release+0x37/0x40 kernel/events/core.c:5393 __fput+0x212/0x8c0 fs/file_table.c:311 task_work_run+0x125/0x1a0 kernel/task_work.c:188 get_signal+0x123e/0x12e0 kernel/signal.c:2673 arch_do_signal_or_restart+0xe6/0x12a0 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: 0033:0x7f15ff81fe59 RSP: 002b:00007f15fda77fd8 EFLAGS: 00000202 ORIG_RAX: 0000000000000038 RAX: fffffffffffffffc RBX: 00007f15ffaa7fa0 RCX: 00007f15ff81fe59 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000004000c0fe RBP: 00007f15ff8b5e6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000 R13: 00007f15ffaa8038 R14: 00007f15ffaa7fa0 R15: 00007ffe65cb7aa8 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8c31ef20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by dhcpcd/3850: #0: ffffffff8d433588 (vlan_ioctl_mutex){+.+.}-{3:3}, at: sock_ioctl+0x21b/0x700 net/socket.c:1229 #1: ffffffff8d44b148 (rtnl_mutex){+.+.}-{3:3}, at: vlan_ioctl_handler+0xef/0x5d0 net/8021q/vlan.c:581 2 locks held by getty/3941: #0: ffff88802bfbe098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc900025e62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x594/0x1a50 drivers/tty/n_tty.c:2158 4 locks held by kworker/u4:8/9000: 3 locks held by kworker/u4:12/9014: #0: ffff888016c79138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1 #1: ffffc900033ffd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285 #2: ffffffff8d44b148 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xa/0x50 net/core/link_watch.c:251 3 locks held by kworker/u4:17/9026: 3 locks held by kworker/1:35/16193: #0: ffff888016c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1 #1: ffffc9000445fd00 (deferred_process_work){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285 #2: ffffffff8d44b148 (rtnl_mutex){+.+.}-{3:3}, at: switchdev_deferred_process_work+0xa/0x20 net/switchdev/switchdev.c:74 2 locks held by syz.2.4981/25351: #0: ffffffff8d43f210 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x324/0x5b0 net/core/net_namespace.c:499 #1: ffffffff8d44b148 (rtnl_mutex){+.+.}-{3:3}, at: cangw_pernet_exit+0xe/0x20 net/can/gw.c:1279 1 lock held by syz.6.4999/25417: #0: ffffffff8d44b148 (rtnl_mutex){+.+.}-{3:3}, at: dev_ioctl+0x5ce/0xe30 net/core/dev_ioctl.c:596 1 lock held by syz.6.4999/25420: #0: ffffffff8d44b148 (rtnl_mutex){+.+.}-{3:3}, at: dev_ioctl+0x5ce/0xe30 net/core/dev_ioctl.c:596 2 locks held by syz.4.5002/25428: #0: ffffffff8d4a7d70 (cb_lock){++++}-{3:3}, at: genl_rcv+0x15/0x40 net/netlink/genetlink.c:802 #1: ffffffff8d44b148 (rtnl_mutex){+.+.}-{3:3}, at: nl80211_pre_doit+0x28/0x540 net/wireless/nl80211.c:14969 1 lock held by syz.0.5003/25437: #0: ffffffff8d44b148 (rtnl_mutex){+.+.}-{3:3}, at: dev_ioctl+0x534/0xe30 net/core/dev_ioctl.c:571 1 lock held by syz.7.5004/25438: #0: ffffffff8d44b148 (rtnl_mutex){+.+.}-{3:3}, at: __tun_chr_ioctl+0x3f3/0x1f30 drivers/net/tun.c:3055 1 lock held by syz.7.5004/25439: #0: ffffffff8d44b148 (rtnl_mutex){+.+.}-{3:3}, at: __tun_chr_ioctl+0x3f3/0x1f30 drivers/net/tun.c:3055 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 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+0xe1b/0xe60 kernel/hung_task.c:369 kthread+0x42e/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 3547 Comm: klogd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:unwind_next_frame+0x1/0x1cf0 arch/x86/kernel/unwind_orc.c:423 Code: 31 c0 5b 41 5e 41 5f c3 89 d9 80 e1 07 80 c1 03 38 c1 7c 97 48 89 df e8 dd 02 89 00 eb 8d 66 2e 0f 1f 84 00 00 00 00 00 90 55 <41> 57 41 56 41 55 41 54 53 48 83 ec 60 48 89 fb 49 be 00 00 00 00 RSP: 0018:ffffc90000dd0718 EFLAGS: 00000202 RAX: 0000000000000001 RBX: ffffc90000dd07e0 RCX: 0000000080000101 RDX: dffffc0000000000 RSI: ffffffff87e97960 RDI: ffffc90000dd0728 RBP: ffffc90000dd07b0 R08: ffffc90000dd07f0 R09: 0000000000000006 R10: dffffc0000000000 R11: fffff520001ba0f1 R12: ffff88807e24d940 R13: ffff888060ea5780 R14: ffffffff81676b20 R15: ffffc90000dd0728 FS: 00007f31ca508c80(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555592aa34e8 CR3: 000000007d8aa000 CR4: 00000000003506e0 DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000200000000300 DR3: 0000200000000300 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: arch_stack_walk+0x10c/0x140 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa6/0xf0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:46 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360 ____kasan_slab_free+0xd5/0x110 mm/kasan/common.c:366 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1710 [inline] slab_free_freelist_hook+0xec/0x170 mm/slub.c:1736 slab_free mm/slub.c:3504 [inline] kfree+0xef/0x2a0 mm/slub.c:4564 ip_dst_metrics_put include/net/ip.h:516 [inline] ip6_dst_destroy+0x96/0x240 net/ipv6/route.c:360 dst_destroy+0xc0/0x2e0 net/core/dst.c:112 rcu_do_batch kernel/rcu/tree.c:2523 [inline] rcu_core+0x96e/0x1650 kernel/rcu/tree.c:2763 handle_softirqs+0x336/0x830 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:memset_erms+0xb/0x10 arch/x86/lib/memset_64.S:65 Code: 03 40 0f b6 f6 48 b8 01 01 01 01 01 01 01 01 48 0f af c6 f3 48 ab 89 d1 f3 aa 4c 89 c8 c3 90 49 89 f9 40 88 f0 48 89 d1 f3 aa <4c> 89 c8 c3 90 49 89 fa 40 0f b6 ce 48 b8 01 01 01 01 01 01 01 01 RSP: 0018:ffffc9000ec27978 EFLAGS: 00000202 RAX: ffffffff840b7700 RBX: ffffffff8a2be260 RCX: 0000000000000000 RDX: 0000000000000018 RSI: 0000000000000000 RDI: ffffc9000ec279f8 RBP: ffffc9000ec27a70 R08: ffffc9000ec279f7 R09: ffffc9000ec279e0 R10: dffffc0000000000 R11: fffff52001d84f3f R12: 1ffff92001d84f38 R13: dffffc0000000000 R14: ffffc9000ec27bc3 R15: ffffc9000ec279e0 sprintf+0xaf/0x140 lib/vsprintf.c:3009 print_time kernel/printk/printk.c:1274 [inline] info_print_prefix+0x168/0x360 kernel/printk/printk.c:1300 record_print_text kernel/printk/printk.c:1349 [inline] syslog_print+0x44e/0x8d0 kernel/printk/printk.c:1560 do_syslog+0x83f/0x930 kernel/printk/printk.c:1679 __do_sys_syslog kernel/printk/printk.c:1771 [inline] __se_sys_syslog kernel/printk/printk.c:1769 [inline] __x64_sys_syslog+0x78/0x90 kernel/printk/printk.c:1769 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f31ca6d2a37 Code: 73 01 c3 48 8b 0d c1 f3 0c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 67 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 91 f3 0c 00 f7 d8 64 89 01 48 RSP: 002b:00007fff4e938f28 EFLAGS: 00000206 ORIG_RAX: 0000000000000067 RAX: ffffffffffffffda RBX: 00007f31ca872490 RCX: 00007f31ca6d2a37 RDX: 00000000000003ff RSI: 00007f31ca872490 RDI: 0000000000000002 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000004000 R11: 0000000000000206 R12: 00007f31ca872490 R13: 00007f31ca84fdfe R14: 00007f31ca872885 R15: 00007f31ca872885