INFO: task syz-executor:4183 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:20744 pid: 4183 ppid: 1 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11bb/0x4390 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 io_schedule+0x7c/0xd0 kernel/sched/core.c:8503 wait_on_page_bit_common+0x815/0xe00 mm/filemap.c:1356 lock_page include/linux/pagemap.h:625 [inline] truncate_inode_pages_range+0x97f/0xef0 mm/truncate.c:394 evict+0x498/0x870 fs/inode.c:649 dispose_list fs/inode.c:680 [inline] evict_inodes+0x604/0x690 fs/inode.c:734 generic_shutdown_super+0x93/0x300 fs/super.c:454 kill_block_super+0x7c/0xe0 fs/super.c:1427 deactivate_locked_super+0x93/0xf0 fs/super.c:335 cleanup_mnt+0x418/0x4d0 fs/namespace.c:1148 task_work_run+0x125/0x1a0 kernel/task_work.c:188 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop+0x10f/0x130 kernel/entry/common.c:181 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: 0033:0x7fa0d388ea77 RSP: 002b:00007ffe1e84bd68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007fa0d388ea77 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe1e84be20 RBP: 00007ffe1e84be20 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffe1e84ceb0 R13: 00007fa0d3911d7d R14: 0000000000047924 R15: 00007ffe1e84cef0 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8c11c720 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by getty/3949: #0: ffff88802c603098 (&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+0x5ba/0x1a30 drivers/tty/n_tty.c:2158 1 lock held by syz-executor/4183: #0: ffff88807bc780e0 (&type->s_umount_key#85){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365 2 locks held by kworker/0:4/4240: #0: ffff888016872138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc9000329fd00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 3 locks held by kworker/0:5/4247: #0: ffff888016870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc9000330fd00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 #2: ffff888060a06240 (&data->fib_lock){+.+.}-{3:3}, at: nsim_fib_event_work+0x271/0x3240 drivers/net/netdevsim/fib.c:1480 3 locks held by kworker/1:6/4256: 3 locks held by kworker/1:8/4296: #0: ffff88802ad76538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc900044dfd00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 #2: ffffffff8d232788 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xc4/0x1520 net/ipv6/addrconf.c:4110 2 locks held by udevd/4344: #0: ffff8880205fc518 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0xf9/0x7d0 block/bdev.c:915 #1: ffff8881473f2468 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0xaa/0xb90 drivers/block/loop.c:1366 5 locks held by kworker/u4:8/4437: #0: ffff8880169cd938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc900034efd00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 #2: ffffffff8d226b10 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x132/0xb80 net/core/net_namespace.c:589 #3: ffffffff8d232788 (rtnl_mutex){+.+.}-{3:3}, at: ip6_tnl_exit_batch_net+0xc0/0x620 net/ipv6/ip6_tunnel.c:2320 #4: ffffffff8c1211a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline] #4: ffffffff8c1211a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x347/0x6b0 kernel/rcu/tree_exp.h:845 3 locks held by kworker/u4:10/4477: #0: ffff8880b913a358 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475 #1: ffff8880b9127888 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x4d6/0x810 kernel/sched/psi.c:891 #2: ffffffff8c11c720 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:312 3 locks held by kworker/0:13/4585: #0: ffff88802ad76538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc9000341fd00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 #2: ffffffff8d232788 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xc4/0x1520 net/ipv6/addrconf.c:4110 1 lock held by syz-executor/8516: #0: ffff8880208a7468 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0xaa/0xb90 drivers/block/loop.c:1366 1 lock held by syz-executor/9669: #0: ffffffff8d232788 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline] #0: ffffffff8d232788 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7a5/0xe90 net/core/rtnetlink.c:5681 ============================================= 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 10/25/2025 Call Trace: dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106 nmi_cpu_backtrace+0x397/0x3d0 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 20 Comm: ksoftirqd/1 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:next_zones_zonelist include/linux/mmzone.h:1166 [inline] RIP: 0010:first_zones_zonelist include/linux/mmzone.h:1192 [inline] RIP: 0010:prepare_alloc_pages+0x2ee/0x5f0 mm/page_alloc.c:5276 Code: ff df 48 8b 34 24 49 8b 16 48 85 d2 0f 85 88 00 00 00 4d 8d 75 08 4c 89 f0 48 c1 e8 03 42 0f b6 04 00 84 c0 0f 85 c0 01 00 00 <41> 39 2e 77 6b 48 83 c6 10 48 89 f0 48 c1 e8 03 42 80 3c 00 00 74 RSP: 0018:ffffc90000da6b10 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffffc90000da6bdc RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffc90000da6bc0 RDI: ffffc90000da6be0 RBP: 0000000000000002 R08: dffffc0000000000 R09: ffffc90000da6b98 R10: fffff520001b4d7d R11: 1ffff920001b4d78 R12: 0000000000000000 R13: ffff88813fffd300 R14: ffff88813fffd308 R15: 1ffff920001b4d78 FS: 0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f9accd40e9c CR3: 000000001e57c000 CR4: 00000000003506e0 Call Trace: __alloc_pages+0x10e/0x470 mm/page_alloc.c:5476 alloc_slab_page mm/slub.c:1780 [inline] allocate_slab mm/slub.c:1917 [inline] new_slab+0xc0/0x4b0 mm/slub.c:1980 ___slab_alloc+0x81e/0xdf0 mm/slub.c:3013 __slab_alloc mm/slub.c:3100 [inline] slab_alloc_node mm/slub.c:3191 [inline] slab_alloc mm/slub.c:3233 [inline] kmem_cache_alloc+0x195/0x290 mm/slub.c:3238 skb_ext_maybe_cow net/core/skbuff.c:6509 [inline] skb_ext_add+0x1c1/0x910 net/core/skbuff.c:6575 nf_bridge_unshare net/bridge/br_netfilter_hooks.c:165 [inline] br_nf_forward_ip+0xc2/0x10a0 net/bridge/br_netfilter_hooks.c:687 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+0x1eb/0x370 include/linux/netfilter.h:300 __br_forward+0x41f/0x600 net/bridge/br_forward.c:115 deliver_clone net/bridge/br_forward.c:131 [inline] maybe_deliver+0xb5/0x150 net/bridge/br_forward.c:190 br_flood+0x2fc/0x450 net/bridge/br_forward.c:232 br_handle_frame_finish+0x1018/0x12c0 net/bridge/br_input.c:180 br_nf_hook_thresh+0x3b2/0x480 net/bridge/br_netfilter_hooks.c:1155 br_nf_pre_routing_finish_ipv6+0x903/0xc80 net/bridge/br_netfilter_ipv6.c:-1 NF_HOOK include/linux/netfilter.h:302 [inline] br_nf_pre_routing_ipv6+0x359/0x650 net/bridge/br_netfilter_ipv6.c:237 nf_hook_entry_hookfn include/linux/netfilter.h:142 [inline] nf_hook_bridge_pre net/bridge/br_input.c:242 [inline] br_handle_frame+0x89b/0x1180 net/bridge/br_input.c:384 __netif_receive_skb_core+0xfb0/0x35d0 net/core/dev.c:5419 __netif_receive_skb_one_core net/core/dev.c:5523 [inline] __netif_receive_skb+0x74/0x290 net/core/dev.c:5639 process_backlog+0x364/0x780 net/core/dev.c:6516 __napi_poll+0xc0/0x430 net/core/dev.c:7075 napi_poll net/core/dev.c:7142 [inline] net_rx_action+0x4a8/0x9c0 net/core/dev.c:7232 handle_softirqs+0x328/0x820 kernel/softirq.c:576 run_ksoftirqd+0x98/0xf0 kernel/softirq.c:943 smpboot_thread_fn+0x4f6/0x970 kernel/smpboot.c:164 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287