INFO: task syz.5.5078:25796 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.5078 state:D stack:27864 pid:25796 tgid:25793 ppid:20233 task_flags:0x400040 flags:0x08080002 Call Trace: context_switch kernel/sched/core.c:5387 [inline] __schedule+0x17b4/0x5680 kernel/sched/core.c:7188 __schedule_loop kernel/sched/core.c:7267 [inline] schedule+0x164/0x360 kernel/sched/core.c:7282 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7339 __mutex_lock_common kernel/locking/mutex.c:712 [inline] __mutex_lock+0x7f5/0x1550 kernel/locking/mutex.c:806 do_ip_setsockopt+0xefa/0x2ea0 net/ipv4/ip_sockglue.c:1077 ip_setsockopt+0x66/0x110 net/ipv4/ip_sockglue.c:1417 do_sock_setsockopt+0x17c/0x1b0 net/socket.c:2381 __sys_setsockopt net/socket.c:2406 [inline] __do_sys_setsockopt net/socket.c:2412 [inline] __se_sys_setsockopt net/socket.c:2409 [inline] __ia32_sys_setsockopt+0x13d/0x1b0 net/socket.c:2409 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0x229/0x6e0 arch/x86/entry/syscall_32.c:307 do_fast_syscall_32+0x33/0x70 arch/x86/entry/syscall_32.c:332 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf702f01c RSP: 002b:00000000f53fc50c EFLAGS: 00000206 ORIG_RAX: 000000000000016e RAX: ffffffffffffffda RBX: 0000000000000009 RCX: 0000000000000000 RDX: 0000000000000024 RSI: 00000000800000c0 RDI: 000000000000000c RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 INFO: task syz.0.5077:25797 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.5077 state:D stack:28056 pid:25797 tgid:25795 ppid:20483 task_flags:0x400040 flags:0x08080002 Call Trace: context_switch kernel/sched/core.c:5387 [inline] __schedule+0x17b4/0x5680 kernel/sched/core.c:7188 __schedule_loop kernel/sched/core.c:7267 [inline] schedule+0x164/0x360 kernel/sched/core.c:7282 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7339 __mutex_lock_common kernel/locking/mutex.c:712 [inline] __mutex_lock+0x7f5/0x1550 kernel/locking/mutex.c:806 __tun_chr_ioctl+0x3bc/0x1e10 drivers/net/tun.c:3080 __do_compat_sys_ioctl fs/ioctl.c:695 [inline] __se_compat_sys_ioctl fs/ioctl.c:638 [inline] __ia32_compat_sys_ioctl+0x5ea/0x950 fs/ioctl.c:638 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0x229/0x6e0 arch/x86/entry/syscall_32.c:307 do_fast_syscall_32+0x33/0x70 arch/x86/entry/syscall_32.c:332 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf700f01c RSP: 002b:00000000f53fd50c EFLAGS: 00000206 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00000000400454ca RDX: 0000000080000040 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Showing all locks held in the system: 2 locks held by kthreadd/2: 2 locks held by kworker/1:0/24: 1 lock held by khungtaskd/30: #0: ffffffff8e95cce0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8e95cce0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8e95cce0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 4 locks held by kworker/u8:3/42: 3 locks held by kworker/R-ipv6_/3187: #0: ffff888031d49940 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3277 [inline] #0: ffff888031d49940 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385 #1: ffffc9000d34fc00 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3278 [inline] #1: ffffc9000d34fc00 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385 #2: ffffffff8fddfa00 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8fddfa00 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x19/0x30 net/ipv6/addrconf.c:4746 6 locks held by kworker/R-bat_e/3412: 2 locks held by klogd/5185: 2 locks held by udevd/5196: 2 locks held by dhcpcd/5490: 5 locks held by dhcpcd/5491: 1 lock held by crond/5568: 2 locks held by getty/5580: #0: ffff8880370170a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000322b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0 drivers/tty/n_tty.c:2211 2 locks held by syz-executor/5812: 3 locks held by kworker/0:6/5916: #0: ffff88813fe57140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3277 [inline] #0: ffff88813fe57140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385 #1: ffffc900046b7c40 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3278 [inline] #1: ffffc900046b7c40 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385 #2: ffffffff8fddfa00 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104 2 locks held by kworker/1:4/5918: 3 locks held by kworker/u8:10/6807: 3 locks held by kworker/u8:11/6809: 3 locks held by kworker/u8:12/6811: 4 locks held by kworker/u8:14/6815: 3 locks held by kworker/u8:15/6817: 3 locks held by kworker/u8:17/6821: #0: ffff88801ae94140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3277 [inline] #0: ffff88801ae94140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385 #1: ffffc90003557c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3278 [inline] #1: ffffc90003557c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385 #2: ffffffff8fddfa00 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313 3 locks held by kworker/u8:0/13791: 2 locks held by kworker/0:5/17141: 9 locks held by kworker/1:5/17439: 2 locks held by kworker/u9:2/20231: 4 locks held by kworker/u8:1/22827: 3 locks held by kworker/u8:2/23215: 3 locks held by kworker/u8:4/25747: 3 locks held by kworker/u8:5/25751: 3 locks held by kworker/u8:6/25752: 2 locks held by syz.6.5075/25781: 1 lock held by syz.6.5075/25790: 1 lock held by syz.5.5078/25796: #0: ffffffff8fddfa00 (rtnl_mutex){+.+.}-{4:4}, at: do_ip_setsockopt+0xefa/0x2ea0 net/ipv4/ip_sockglue.c:1077 1 lock held by syz.0.5077/25797: #0: ffffffff8fddfa00 (rtnl_mutex){+.+.}-{4:4}, at: __tun_chr_ioctl+0x3bc/0x1e10 drivers/net/tun.c:3080 1 lock held by syz.0.5077/25803: #0: ffffffff8fddfa00 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8fddfa00 (rtnl_mutex){+.+.}-{4:4}, at: rtnetlink_rcv_msg+0x722/0xbe0 net/core/rtnetlink.c:7000 1 lock held by syz.3.5079/25802: #0: ffffffff8fddfa00 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8fddfa00 (rtnl_mutex){+.+.}-{4:4}, at: rtnetlink_rcv_msg+0x722/0xbe0 net/core/rtnetlink.c:7000 1 lock held by syz.7.5080/25806: #0: ffffffff8fddfa00 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8fddfa00 (rtnl_mutex){+.+.}-{4:4}, at: dev_ioctl+0x7a4/0x1150 net/core/dev_ioctl.c:813 3 locks held by kworker/u8:7/25809: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0xfd3/0x1030 kernel/hung_task.c:561 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 3412 Comm: kworker/R-bat_e Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Workqueue: bat_events batadv_tt_purge RIP: 0010:check_wait_context kernel/locking/lockdep.c:4869 [inline] RIP: 0010:__lock_acquire+0x46a/0x2cf0 kernel/locking/lockdep.c:5187 Code: 0b 00 00 41 8d 4c 24 ff 83 f9 ff 41 bd ff ff ff ff 44 0f 4c e9 41 ff c5 41 8d 5c 24 01 49 ff cc 89 d9 83 c1 fe 78 40 45 89 e7 <41> 81 e7 ff ff ff 7f 83 f9 31 73 1d 4b 8d 0c bf 41 8b 8c ce b0 0b RSP: 0018:ffffc90000a077f0 EFLAGS: 00000013 RAX: 0000000000022007 RBX: 0000000000000003 RCX: 0000000000000001 RDX: 0000000000000003 RSI: 0000000000002000 RDI: 0000000000000000 RBP: ffff88803312ab18 R08: ffffffff81770256 R09: ffffffff8e95cce0 R10: ffffc90000a07af8 R11: ffffffff81b0f560 R12: 0000000000000001 R13: 0000000000000000 R14: ffff888033129ec0 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff888125325000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000008011f018 CR3: 00000000530f4000 CR4: 00000000003526f0 DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000083 DR3: 0000000000000030 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 rcu_lock_acquire include/linux/rcupdate.h:300 [inline] rcu_read_lock include/linux/rcupdate.h:838 [inline] class_rcu_constructor include/linux/rcupdate.h:1181 [inline] unwind_next_frame+0xc3/0x2550 arch/x86/kernel/unwind_orc.c:495 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2689 [inline] slab_free mm/slub.c:6246 [inline] kmem_cache_free+0x182/0x650 mm/slub.c:6373 skb_ext_reset include/linux/skbuff.h:5116 [inline] skb_release_head_state+0x270/0x360 net/core/skbuff.c:1181 skb_release_all net/core/skbuff.c:1187 [inline] __kfree_skb+0x24/0x210 net/core/skbuff.c:1203 kfree_skb_reason include/linux/skbuff.h:1322 [inline] kfree_skb include/linux/skbuff.h:1331 [inline] ip6_mc_input+0x8de/0xbd0 net/ipv6/ip6_input.c:633 ip_sabotage_in+0x1e1/0x270 net/bridge/br_netfilter_hooks.c:984 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_slow+0xc5/0x220 net/netfilter/core.c:619 nf_hook include/linux/netfilter.h:273 [inline] NF_HOOK+0x21f/0x3c0 include/linux/netfilter.h:316 __netif_receive_skb_one_core net/core/dev.c:6209 [inline] __netif_receive_skb net/core/dev.c:6322 [inline] netif_receive_skb_internal net/core/dev.c:6408 [inline] netif_receive_skb+0x278/0xbf0 net/core/dev.c:6467 NF_HOOK+0xa4/0x3a0 include/linux/netfilter.h:318 br_handle_frame_finish+0x1541/0x1c80 net/bridge/br_input.c:-1 br_nf_hook_thresh+0x3dd/0x4c0 net/bridge/br_netfilter_hooks.c:-1 br_nf_pre_routing_finish_ipv6+0x91f/0xc30 net/bridge/br_netfilter_ipv6.c:-1 NF_HOOK include/linux/netfilter.h:318 [inline] br_nf_pre_routing_ipv6+0x374/0x6f0 net/bridge/br_netfilter_ipv6.c:183 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_bridge_pre net/bridge/br_input.c:291 [inline] br_handle_frame+0x1277/0x1510 net/bridge/br_input.c:442 __netif_receive_skb_core+0x98f/0x3170 net/core/dev.c:6096 __netif_receive_skb_one_core net/core/dev.c:6207 [inline] __netif_receive_skb net/core/dev.c:6322 [inline] process_backlog+0x76d/0x1950 net/core/dev.c:6673 __napi_poll+0xae/0x340 net/core/dev.c:7737 napi_poll net/core/dev.c:7800 [inline] net_rx_action+0x627/0xf70 net/core/dev.c:7957 handle_softirqs+0x22a/0x840 kernel/softirq.c:622 do_softirq+0x76/0xd0 kernel/softirq.c:523 __local_bh_enable_ip+0xf8/0x130 kernel/softirq.c:450 spin_unlock_bh include/linux/spinlock.h:396 [inline] batadv_tt_global_purge net/batman-adv/translation-table.c:2255 [inline] batadv_tt_purge+0x4d1/0x9e0 net/batman-adv/translation-table.c:3515 process_one_work kernel/workqueue.c:3302 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3385 rescuer_thread+0x827/0x1130 kernel/workqueue.c:3609 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245