INFO: task kworker/u8:5:145 blocked for more than 143 seconds. Not tainted 6.9.0-syzkaller-01768-ga5131c3fdf26 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:5 state:D stack:14192 pid:145 tgid:145 ppid:2 flags:0x00004000 Workqueue: ipv6_addrconf addrconf_dad_work Call Trace: context_switch kernel/sched/core.c:5409 [inline] __schedule+0x1796/0x4a00 kernel/sched/core.c:6746 __schedule_loop kernel/sched/core.c:6823 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6838 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6895 __mutex_lock_common kernel/locking/mutex.c:684 [inline] __mutex_lock+0x6a4/0xd70 kernel/locking/mutex.c:752 addrconf_dad_work+0xd0/0x16f0 net/ipv6/addrconf.c:4192 process_one_work kernel/workqueue.c:3267 [inline] process_scheduled_works+0xa10/0x17c0 kernel/workqueue.c:3348 worker_thread+0x86d/0xd70 kernel/workqueue.c:3429 kthread+0x2f0/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Showing all locks held in the system: 2 locks held by init/1: 2 locks held by kworker/u8:1/12: #0: ffff888015089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3242 [inline] #0: ffff888015089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x8e0/0x17c0 kernel/workqueue.c:3348 #1: ffffc90000117d00 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3243 [inline] #1: ffffc90000117d00 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_scheduled_works+0x91b/0x17c0 kernel/workqueue.c:3348 3 locks held by kworker/1:0/25: #0: ffff888015080948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3242 [inline] #0: ffff888015080948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x8e0/0x17c0 kernel/workqueue.c:3348 #1: ffffc900001f7d00 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3243 [inline] #1: ffffc900001f7d00 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0x91b/0x17c0 kernel/workqueue.c:3348 #2: ffffffff8f599888 (rtnl_mutex){+.+.}-{3:3}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104 1 lock held by khungtaskd/30: #0: ffffffff8e336020 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #0: ffffffff8e336020 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #0: ffffffff8e336020 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6614 5 locks held by kworker/u9:0/53: #0: ffff8881a659a948 ((wq_completion)hci5){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3242 [inline] #0: ffff8881a659a948 ((wq_completion)hci5){+.+.}-{0:0}, at: process_scheduled_works+0x8e0/0x17c0 kernel/workqueue.c:3348 #1: ffffc90000bd7d00 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3243 [inline] #1: ffffc90000bd7d00 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0x91b/0x17c0 kernel/workqueue.c:3348 #2: ffff8881e35a1060 (&hdev->req_lock){+.+.}-{3:3}, at: hci_cmd_sync_work+0x1ec/0x400 net/bluetooth/hci_sync.c:309 #3: ffff8881e35a0078 (&hdev->lock){+.+.}-{3:3}, at: hci_abort_conn_sync+0x1ea/0xde0 net/bluetooth/hci_sync.c:5548 #4: ffff8880b943e658 (&rq->__lock){-.-.}-{2:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #4: ffff8880b943e658 (&rq->__lock){-.-.}-{2:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #4: ffff8880b943e658 (&rq->__lock){-.-.}-{2:2}, at: shrink_slab+0x12b/0x14d0 mm/shrinker.c:649 1 lock held by kswapd1/89: 3 locks held by kworker/u8:5/145: #0: ffff888029f86148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3242 [inline] #0: ffff888029f86148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x8e0/0x17c0 kernel/workqueue.c:3348 #1: ffffc90002d17d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3243 [inline] #1: ffffc90002d17d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x91b/0x17c0 kernel/workqueue.c:3348 #2: ffffffff8f599888 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xd0/0x16f0 net/ipv6/addrconf.c:4192 4 locks held by kworker/u8:6/2426: 6 locks held by kworker/u8:8/2822: 1 lock held by jbd2/sda1-8/4493: 1 lock held by udevd/4530: 2 locks held by getty/4832: #0: ffff88802a0ac0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002f0e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6b5/0x1e10 drivers/tty/n_tty.c:2201 2 locks held by sshd/5067: #0: ffff8880221ec420 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:165 [inline] #0: ffff8880221ec420 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully mm/memory.c:5633 [inline] #0: ffff8880221ec420 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x32/0x2f0 mm/memory.c:5693 #1: ffffffff8e42a400 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:3771 [inline] #1: ffffffff8e42a400 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:3796 [inline] #1: ffffffff8e42a400 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath+0xd31/0x23d0 mm/page_alloc.c:4202 3 locks held by syz-fuzzer/5070: 2 locks held by syz-fuzzer/5075: 3 locks held by syz-fuzzer/5087: 4 locks held by kworker/u9:1/17744: 1 lock held by syz-executor.2/18180: #0: ffff888065c500e0 (&type->s_umount_key#60){++++}-{3:3}, at: __super_lock fs/super.c:56 [inline] #0: ffff888065c500e0 (&type->s_umount_key#60){++++}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff888065c500e0 (&type->s_umount_key#60){++++}-{3:3}, at: deactivate_super+0xb5/0xf0 fs/super.c:504 4 locks held by kworker/u9:2/18553: #0: ffff88805e87e148 ((wq_completion)hci0){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3242 [inline] #0: ffff88805e87e148 ((wq_completion)hci0){+.+.}-{0:0}, at: process_scheduled_works+0x8e0/0x17c0 kernel/workqueue.c:3348 #1: ffffc90003377d00 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3243 [inline] #1: ffffc90003377d00 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0x91b/0x17c0 kernel/workqueue.c:3348 #2: ffff888073ef9060 (&hdev->req_lock){+.+.}-{3:3}, at: hci_cmd_sync_work+0x1ec/0x400 net/bluetooth/hci_sync.c:309 #3: ffff888073ef8078 (&hdev->lock){+.+.}-{3:3}, at: hci_abort_conn_sync+0x1ea/0xde0 net/bluetooth/hci_sync.c:5548 2 locks held by syz-executor.4/18796: 3 locks held by syz-executor.2/19219: 2 locks held by syz-executor.1/19286: 2 locks held by rm/19503: 3 locks held by modprobe/19505: 5 locks held by kworker/u8:7/19507: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 30 Comm: khungtaskd Not tainted 6.9.0-syzkaller-01768-ga5131c3fdf26 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline] watchdog+0xfde/0x1020 kernel/hung_task.c:380 kthread+0x2f0/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 5075 Comm: syz-fuzzer Not tainted 6.9.0-syzkaller-01768-ga5131c3fdf26 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 RIP: 0010:__ref_is_percpu include/linux/percpu-refcount.h:174 [inline] RIP: 0010:percpu_ref_tryget_many include/linux/percpu-refcount.h:243 [inline] RIP: 0010:percpu_ref_tryget+0x82/0x180 include/linux/percpu-refcount.h:266 Code: 1f c6 05 fa 02 92 0d 01 48 c7 c7 e0 3b d7 8b be 0f 03 00 00 48 c7 c2 20 3c d7 8b e8 f8 73 72 ff 49 bf 00 00 00 00 00 fc ff df <48> 89 d8 48 c1 e8 03 42 80 3c 38 00 74 08 48 89 df e8 08 15 f7 ff RSP: 0000:ffffc900034c6c30 EFLAGS: 00000202 RAX: 0000000000000001 RBX: ffff888078a32010 RCX: ffff88807a811e00 RDX: dffffc0000000000 RSI: ffffffff8c1ec8c0 RDI: ffffffff8c1ec880 RBP: ffff888078a32000 R08: ffffffff92f0b587 R09: 1ffffffff25e16b0 R10: dffffc0000000000 R11: fffffbfff25e16b1 R12: ffff888078a32054 R13: ffff888016ac4000 R14: ffffffff82009d14 R15: dffffc0000000000 FS: 000000c000d1e490(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055dff07a1696 CR3: 0000000075c00000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: css_tryget include/linux/cgroup_refcnt.h:45 [inline] mem_cgroup_iter+0x2d3/0x560 mm/memcontrol.c:1228 shrink_node_memcgs mm/vmscan.c:5884 [inline] shrink_node+0x135b/0x2d60 mm/vmscan.c:5908 shrink_zones mm/vmscan.c:6152 [inline] do_try_to_free_pages+0x695/0x1af0 mm/vmscan.c:6214 try_to_free_pages+0x760/0x1100 mm/vmscan.c:6449 __perform_reclaim mm/page_alloc.c:3774 [inline] __alloc_pages_direct_reclaim mm/page_alloc.c:3796 [inline] __alloc_pages_slowpath+0xdc3/0x23d0 mm/page_alloc.c:4202 __alloc_pages+0x43e/0x6c0 mm/page_alloc.c:4588 alloc_pages_mpol+0x3e8/0x680 mm/mempolicy.c:2264 alloc_pages mm/mempolicy.c:2335 [inline] folio_alloc+0x128/0x180 mm/mempolicy.c:2342 filemap_alloc_folio+0xdf/0x500 mm/filemap.c:984 __filemap_get_folio+0x41a/0xbb0 mm/filemap.c:1926 filemap_fault+0xba2/0x1760 mm/filemap.c:3299 __do_fault+0x135/0x460 mm/memory.c:4531 do_read_fault mm/memory.c:4894 [inline] do_fault mm/memory.c:5024 [inline] do_pte_missing mm/memory.c:3880 [inline] handle_pte_fault mm/memory.c:5300 [inline] __handle_mm_fault+0x45fe/0x7250 mm/memory.c:5441 handle_mm_fault+0x27f/0x770 mm/memory.c:5606 do_user_addr_fault arch/x86/mm/fault.c:1332 [inline] handle_page_fault arch/x86/mm/fault.c:1475 [inline] exc_page_fault+0x446/0x8a0 arch/x86/mm/fault.c:1533 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x43d098 Code: Unable to access opcode bytes at 0x43d06e. RSP: 002b:000000c000d378e0 EFLAGS: 00010202 RAX: 00000000013b25a8 RBX: 00000000014b5540 RCX: 0000000000000000 RDX: 00000000013b25a8 RSI: 00000000009c053f RDI: 0000000000e4fcc0 RBP: 000000c000d37950 R08: 00000000ffffffff R09: 0000000000000080 R10: 0000000000000001 R11: 000000000001960e R12: 0000000000000002 R13: ffffffffffffffff R14: 000000c0001c4820 R15: 0000000000000000 ICMPv6: ndisc: ndisc_alloc_skb failed to allocate an skb ICMPv6: ndisc: ndisc_alloc_skb failed to allocate an skb