INFO: task syz-executor:6028 blocked for more than 148 seconds. Tainted: G L syzkaller #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:23720 pid:6028 tgid:6028 ppid:1 task_flags:0x40054c flags:0x00080003 Call Trace: context_switch kernel/sched/core.c:5533 [inline] __schedule+0x1259/0x6920 kernel/sched/core.c:7284 __schedule_loop kernel/sched/core.c:7361 [inline] schedule+0xdd/0x2c0 kernel/sched/core.c:7376 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7433 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0xccb/0x1bd0 kernel/locking/mutex.c:821 tun_detach drivers/net/tun.c:650 [inline] tun_chr_close+0x38/0x220 drivers/net/tun.c:3587 __fput+0x3ff/0xb50 fs/file_table.c:512 task_work_run+0x150/0x240 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x951/0x2ae0 kernel/exit.c:1012 do_group_exit+0xd5/0x2a0 kernel/exit.c:1155 get_signal+0x1ec7/0x21e0 kernel/signal.c:3112 arch_do_signal_or_restart+0x91/0x7e0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline] exit_to_user_mode_loop+0x139/0x700 kernel/entry/common.c:101 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:343 [inline] do_syscall_64+0x661/0x790 arch/x86/entry/syscall_64.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f165199f92a RSP: 002b:00007ffd77f647c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000037 RAX: 0000000000000000 RBX: 00007ffd77f647f0 RCX: 00007f165199f92a RDX: 0000000000000040 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 0000000000000003 R08: 00007ffd77f647ec R09: 0000000000000000 R10: 00007ffd77f647f0 R11: 0000000000000246 R12: 00007f1651beffc0 R13: 00007ffd77f647ec R14: 0000000000000000 R15: 00007f1651bf2180 INFO: task kworker/0:7:6211 blocked for more than 148 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:7 state:D stack:21464 pid:6211 tgid:6211 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events switchdev_deferred_process_work Call Trace: context_switch kernel/sched/core.c:5533 [inline] __schedule+0x1259/0x6920 kernel/sched/core.c:7284 __schedule_loop kernel/sched/core.c:7361 [inline] schedule+0xdd/0x2c0 kernel/sched/core.c:7376 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7433 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0xccb/0x1bd0 kernel/locking/mutex.c:821 switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104 process_one_work+0xac7/0x1b10 kernel/workqueue.c:3396 process_scheduled_works kernel/workqueue.c:3479 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3560 kthread+0x373/0x450 kernel/kthread.c:436 ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Showing all locks held in the system: locks held by init/1: 2, last CPU#0: #0: ffff88807dd020b0 (&type->i_mutex_dir_key#5){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1039 [inline] #0: ffff88807dd020b0 (&type->i_mutex_dir_key#5){++++}-{4:4}, at: lookup_slow+0x42/0x70 fs/namei.c:1935 #1: ffffffff8effd218 (remove_cache_srcu){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:198 [inline] #1: ffffffff8effd218 (remove_cache_srcu){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:305 [inline] #1: ffffffff8effd218 (remove_cache_srcu){.+.+}-{0:0}, at: kasan_quarantine_reduce+0x8a/0x1f0 mm/kasan/quarantine.c:259 locks held by kworker/u8:1/13: 2, last CPU#0: #0: ffff88807f25a940 ((wq_completion)wg-kex-wg0#6){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3371 #1: ffffc90000127d08 ((work_completion)(&peer->transmit_handshake_work)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3372 locks held by khungtaskd/32: 1, last CPU#0: #0: ffffffff8edec4e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffffffff8edec4e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8edec4e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6871 locks held by kworker/u8:2/43: 2, last CPU#0: #0: ffff88801c093940 ((wq_completion)events_dfl_long){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3371 #1: ffffc90000b37d08 ((work_completion)(&(&ipvs->defense_work)->work)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3372 locks held by kworker/u8:3/50: 7, last CPU#1: #0: ffff88801c094140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3371 #1: ffffc90000ba7d08 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3372 #2: ffff8880276d1258 (&devlink->lock_key#3){+.+.}-{4:4}, at: nsim_dev_trap_report_work+0x56/0xd20 drivers/net/netdevsim/dev.c:834 #3: ffff888055a504e0 (&nsim_trap_data->trap_lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock.h:347 [inline] #3: ffff888055a504e0 (&nsim_trap_data->trap_lock){+.+.}-{3:3}, at: nsim_dev_trap_report drivers/net/netdevsim/dev.c:787 [inline] #3: ffff888055a504e0 (&nsim_trap_data->trap_lock){+.+.}-{3:3}, at: nsim_dev_trap_report_work+0x1c7/0xd20 drivers/net/netdevsim/dev.c:847 #4: ffffffff8edec4e0 (rcu_read_lock){....}-{1:3}, at: local_lock_release include/linux/local_lock_internal.h:62 [inline] #4: ffffffff8edec4e0 (rcu_read_lock){....}-{1:3}, at: process_backlog+0x437/0x1600 net/core/dev.c:6726 #5: ffffffff8edec4e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #5: ffffffff8edec4e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #5: ffffffff8edec4e0 (rcu_read_lock){....}-{1:3}, at: nf_hook include/linux/netfilter.h:249 [inline] #5: ffffffff8edec4e0 (rcu_read_lock){....}-{1:3}, at: NF_HOOK include/linux/netfilter.h:323 [inline] #5: ffffffff8edec4e0 (rcu_read_lock){....}-{1:3}, at: __br_forward+0x21f/0x970 net/bridge/br_forward.c:115 #6: ffffffff8edec4e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #6: ffffffff8edec4e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #6: ffffffff8edec4e0 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1216 [inline] #6: ffffffff8edec4e0 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0xbd/0x2090 arch/x86/kernel/unwind_orc.c:495 locks held by kworker/u8:8/1165: 3, last CPU#0: #0: ffff88801c094140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3371 #1: ffffc90005517d08 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3372 #2: ffff888055f90258 (&devlink->lock_key#2){+.+.}-{4:4}, at: nsim_dev_trap_report_work+0x56/0xd20 drivers/net/netdevsim/dev.c:834 locks held by kworker/u8:10/2971: 3, last CPU#0: #0: ffff88801c094140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3371 #1: ffffc9000ed8fd08 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3372 #2: ffff88805541c258 (&devlink->lock_key#4){+.+.}-{4:4}, at: nsim_dev_trap_report_work+0x56/0xd20 drivers/net/netdevsim/dev.c:834 locks held by klogd/4960: 1, last CPU#0: #0: ffffffff8edec4e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffffffff8edec4e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8edec4e0 (rcu_read_lock){....}-{1:3}, at: sock_def_readable+0x90/0x600 net/core/sock.c:3665 locks held by udevd/4971: 2, last CPU#0: #0: ffffffff8f90a838 (tomoyo_ss){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:198 [inline] #0: ffffffff8f90a838 (tomoyo_ss){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:305 [inline] #0: ffffffff8f90a838 (tomoyo_ss){.+.+}-{0:0}, at: tomoyo_read_lock security/tomoyo/common.h:1112 [inline] #0: ffffffff8f90a838 (tomoyo_ss){.+.+}-{0:0}, at: tomoyo_path_perm+0x262/0x460 security/tomoyo/file.c:826 #1: ffffffff8effd218 (remove_cache_srcu){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:198 [inline] #1: ffffffff8effd218 (remove_cache_srcu){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:305 [inline] #1: ffffffff8effd218 (remove_cache_srcu){.+.+}-{0:0}, at: kasan_quarantine_reduce+0x8a/0x1f0 mm/kasan/quarantine.c:259 locks held by dhcpcd/5265: 2, last CPU#0: #0: ffffffff8effd218 (remove_cache_srcu){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:198 [inline] #0: ffffffff8effd218 (remove_cache_srcu){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:305 [inline] #0: ffffffff8effd218 (remove_cache_srcu){.+.+}-{0:0}, at: kasan_quarantine_reduce+0x8a/0x1f0 mm/kasan/quarantine.c:259 #1: ffffffff8edec4e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffffff8edec4e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffffff8edec4e0 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1216 [inline] #1: ffffffff8edec4e0 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0xbd/0x2090 arch/x86/kernel/unwind_orc.c:495 locks held by dhcpcd/5266: 1, last CPU#0: #0: ffffffff8effd218 (remove_cache_srcu){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:198 [inline] #0: ffffffff8effd218 (remove_cache_srcu){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:305 [inline] #0: ffffffff8effd218 (remove_cache_srcu){.+.+}-{0:0}, at: kasan_quarantine_reduce+0x8a/0x1f0 mm/kasan/quarantine.c:259 locks held by getty/5356: 2, on CPU#1: #0: ffff88803406e0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900032262e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x14e0 drivers/tty/n_tty.c:2211 locks held by syz-executor/6026: 1, on CPU#0: #0: ffffffff90cd3e80 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:650 [inline] #0: ffffffff90cd3e80 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x38/0x220 drivers/net/tun.c:3587 locks held by syz-executor/6028: 1, on CPU#1: #0: ffffffff90cd3e80 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:650 [inline] #0: ffffffff90cd3e80 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x38/0x220 drivers/net/tun.c:3587 locks held by syz-executor/6029: 1, on CPU#0: #0: ffffffff90cd3e80 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:650 [inline] #0: ffffffff90cd3e80 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x38/0x220 drivers/net/tun.c:3587 locks held by kworker/0:4/6138: 2, last CPU#0: #0: ffff88801c059d40 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3371 #1: ffffc9000352fd08 ((work_completion)(&(&gc->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3372 locks held by kworker/1:7/6146: 2, last CPU#1: #0: ffff88801c059d40 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3371 #1: ffffc90003917d08 ((work_completion)(&(&tbl->gc_work)->work)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3372 locks held by kworker/0:7/6211: 3, on CPU#0: #0: ffff88801c05b140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3371 #1: ffffc900031dfd08 (deferred_process_work){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3372 #2: ffffffff90cd3e80 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104 locks held by kworker/1:12/14055: 3, last CPU#1: #0: ffff88805686d940 ((wq_completion)wg-kex-wg2#10){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3371 #1: ffffc90005367d08 ((work_completion)(&({ do { const void __seg_gs *__vpp_verify = (typeof((worker) + 0))((void *)0); (void)__vpp_verify; } while (0); ({ unsigned long __ptr; __asm__ ("" : "=r"(__ptr) : "0"((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker))))); (typeof((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker))))) (__ptr + (((__per_cpu_offset[(cpu)])))); }); })->work)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3372 #2: ffff8880554f7028 (&handshake->lock){++++}-{4:4}, at: wg_noise_handshake_begin_session+0x30/0xe40 drivers/net/wireguard/noise.c:822 locks held by kworker/u8:5/15049: 2, last CPU#0: #0: ffff888034117940 ((wq_completion)bat_events){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3371 #1: ffffc900030afd08 ((work_completion)(&(&bat_priv->tt.work)->work)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3372 locks held by kworker/u8:7/15051: 7, last CPU#0: #0: ffff88801d2d8940 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3371 #1: ffffc90002f4fd08 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3372 #2: ffffffff90cbb3a8 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xb8/0x920 net/core/net_namespace.c:677 #3: ffff88802ba7e128 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #3: ffff88802ba7e128 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:124 [inline] #3: ffff88802ba7e128 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x19e/0x370 net/devlink/core.c:575 #4: ffff88802ba7d258 (&devlink->lock_key#5){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:308 [inline] #4: ffff88802ba7d258 (&devlink->lock_key#5){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:125 [inline] #4: ffff88802ba7d258 (&devlink->lock_key#5){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x1b4/0x370 net/devlink/core.c:575 #5: ffffffff90cd3e80 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0x1a6/0x970 drivers/net/netdevsim/netdev.c:1193 #6: ffff888077220e70 (&dev_instance_lock_key#23){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2861 [inline] #6: ffff888077220e70 (&dev_instance_lock_key#23){+.+.}-{4:4}, at: netdev_lock_ops include/net/netdev_lock.h:42 [inline] #6: ffff888077220e70 (&dev_instance_lock_key#23){+.+.}-{4:4}, at: netdev_lock_ops include/net/netdev_lock.h:39 [inline] #6: ffff888077220e70 (&dev_instance_lock_key#23){+.+.}-{4:4}, at: unregister_netdevice_many_notify+0xd48/0x2150 net/core/dev.c:12504 locks held by kworker/u8:9/15053: 4, last CPU#0: #0: ffff88807c4cd940 ((wq_completion)wg-kex-wg0#8){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3371 #1: ffffc90002f1fd08 ((work_completion)(&peer->transmit_handshake_work)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3372 #2: ffff88802d491440 (&wg->static_identity.lock){++++}-{4:4}, at: wg_noise_handshake_create_initiation+0xec/0x610 drivers/net/wireguard/noise.c:529 #3: ffff8880559bbea0 (&handshake->lock){++++}-{4:4}, at: wg_noise_handshake_create_initiation+0x100/0x610 drivers/net/wireguard/noise.c:530 locks held by kworker/u8:14/21460: 2, last CPU#0: #0: ffff88807f25a940 ((wq_completion)wg-kex-wg0#6){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3371 #1: ffffc90004287d08 ((work_completion)(&peer->transmit_handshake_work)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3372 locks held by dhcpcd/21470: 1, last CPU#0: #0: ffffffff8effd218 (remove_cache_srcu){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:198 [inline] #0: ffffffff8effd218 (remove_cache_srcu){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:305 [inline] #0: ffffffff8effd218 (remove_cache_srcu){.+.+}-{0:0}, at: kasan_quarantine_reduce+0x8a/0x1f0 mm/kasan/quarantine.c:259 locks held by syz-executor/21471: 2, last CPU#0: #0: ffff88803080aa20 (&sig->cred_guard_mutex){+.+.}-{4:4}, at: prepare_bprm_creds fs/exec.c:1423 [inline] #0: ffff88803080aa20 (&sig->cred_guard_mutex){+.+.}-{4:4}, at: bprm_execve+0xa3/0x1940 fs/exec.c:1846 #1: ffffffff8effd218 (remove_cache_srcu){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:198 [inline] #1: ffffffff8effd218 (remove_cache_srcu){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:305 [inline] #1: ffffffff8effd218 (remove_cache_srcu){.+.+}-{0:0}, at: kasan_quarantine_reduce+0x8a/0x1f0 mm/kasan/quarantine.c:259 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 32 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2026 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:123 nmi_trigger_cpumask_backtrace+0x21f/0x2a0 lib/nmi_backtrace.c:66 trigger_all_cpu_backtrace include/linux/nmi.h:164 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x141/0x190 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0xcb1/0x1030 kernel/hung_task.c:561 kthread+0x373/0x450 kernel/kthread.c:436 ret_from_fork+0x730/0xd60 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: 50 Comm: kworker/u8:3 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2026 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:unwind_get_return_address+0x0/0xa0 arch/x86/kernel/unwind_orc.c:381 Code: 2f ff ff ff e8 f1 c7 c5 00 eb a8 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 48 b8 00 00 00 00 00 fc ff df 48 89 fa 55 48 c1 ea 03 RSP: 0018:ffffc90000a178f0 EFLAGS: 00000202 RAX: 0000000000000001 RBX: ffffc90000a178f8 RCX: ffffc90000a1784c RDX: 0000000000000000 RSI: ffffffff8e366aae RDI: ffffc90000a178f8 RBP: ffffc90000a17988 R08: 0000000000000001 R09: 0000000000000007 R10: 0000000000000200 R11: 000000000000d0d9 R12: ffffffff81f5ef20 R13: ffffc90000a179b8 R14: 0000000000000000 R15: ffff88801c7b4b00 FS: 0000000000000000(0000) GS:ffff888123c54000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7fabb15b45 CR3: 000000000eb96000 CR4: 00000000003526f0 Call Trace: arch_stack_walk+0xa6/0xf0 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2748 [inline] slab_free mm/slub.c:6508 [inline] kmem_cache_free+0x127/0x6c0 mm/slub.c:6635 __skb_ext_put+0x102/0x2f0 net/core/skbuff.c:7327 __skb_ext_del+0xf8/0x380 net/core/skbuff.c:7294 skb_ext_del include/linux/skbuff.h:5130 [inline] nf_bridge_info_free net/bridge/br_netfilter_hooks.c:157 [inline] br_nf_dev_queue_xmit+0x7a5/0x2780 net/bridge/br_netfilter_hooks.c:917 NF_HOOK include/linux/netfilter.h:325 [inline] NF_HOOK include/linux/netfilter.h:319 [inline] br_nf_post_routing+0xcbb/0x16a0 net/bridge/br_netfilter_hooks.c:964 nf_hook_entry_hookfn include/linux/netfilter.h:165 [inline] nf_hook_slow+0xbf/0x220 net/netfilter/core.c:619 nf_hook include/linux/netfilter.h:280 [inline] NF_HOOK include/linux/netfilter.h:323 [inline] br_forward_finish+0x261/0x4d0 net/bridge/br_forward.c:66 br_nf_hook_thresh+0x30d/0x420 net/bridge/br_netfilter_hooks.c:1165 br_nf_forward_finish+0x693/0xb30 net/bridge/br_netfilter_hooks.c:667 NF_HOOK include/linux/netfilter.h:325 [inline] NF_HOOK include/linux/netfilter.h:319 [inline] br_nf_forward_ip.part.0+0x61e/0x820 net/bridge/br_netfilter_hooks.c:721 br_nf_forward_ip net/bridge/br_netfilter_hooks.c:681 [inline] br_nf_forward+0xfe5/0x19f0 net/bridge/br_netfilter_hooks.c:778 nf_hook_entry_hookfn include/linux/netfilter.h:165 [inline] nf_hook_slow+0xbf/0x220 net/netfilter/core.c:619 nf_hook include/linux/netfilter.h:280 [inline] NF_HOOK include/linux/netfilter.h:323 [inline] __br_forward+0x2f7/0x970 net/bridge/br_forward.c:115 deliver_clone net/bridge/br_forward.c:131 [inline] maybe_deliver+0xf0/0x180 net/bridge/br_forward.c:191 br_flood+0x29b/0x7b0 net/bridge/br_forward.c:245 br_handle_frame_finish+0xfe2/0x1f70 net/bridge/br_input.c:229 br_nf_hook_thresh+0x30d/0x420 net/bridge/br_netfilter_hooks.c:1165 br_nf_pre_routing_finish_ipv6+0x659/0xdd0 net/bridge/br_netfilter_ipv6.c:153 NF_HOOK include/linux/netfilter.h:325 [inline] br_nf_pre_routing_ipv6+0x39c/0x8b0 net/bridge/br_netfilter_ipv6.c:183 br_nf_pre_routing+0x90f/0x1560 net/bridge/br_netfilter_hooks.c:513 nf_hook_entry_hookfn include/linux/netfilter.h:165 [inline] nf_hook_bridge_pre net/bridge/br_input.c:291 [inline] br_handle_frame+0xd59/0x1670 net/bridge/br_input.c:451 __netif_receive_skb_core.constprop.0+0x6c5/0x3530 net/core/dev.c:6151 __netif_receive_skb_one_core+0xb0/0x1e0 net/core/dev.c:6262 __netif_receive_skb+0x1f/0x120 net/core/dev.c:6377 process_backlog+0x487/0x1600 net/core/dev.c:6728 __napi_poll.constprop.0+0xaf/0x450 net/core/dev.c:7787 napi_poll net/core/dev.c:7850 [inline] net_rx_action+0xa40/0xf20 net/core/dev.c:8007 handle_softirqs+0x1e6/0x9d0 kernel/softirq.c:645 do_softirq kernel/softirq.c:546 [inline] do_softirq+0xaf/0xf0 kernel/softirq.c:533 __local_bh_enable_ip+0xff/0x120 kernel/softirq.c:473 local_bh_enable include/linux/bottom_half.h:33 [inline] __alloc_skb+0x5db/0x710 net/core/skbuff.c:699 alloc_skb include/linux/skbuff.h:1384 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:744 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:801 [inline] nsim_dev_trap_report_work+0x2af/0xd20 drivers/net/netdevsim/dev.c:847 process_one_work+0xac7/0x1b10 kernel/workqueue.c:3396 process_scheduled_works kernel/workqueue.c:3479 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3560 kthread+0x373/0x450 kernel/kthread.c:436 ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245