INFO: task syz-executor.4:7342 blocked for more than 143 seconds. Not tainted 6.8.0-syzkaller-08951-gfe46a7dd189e #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.4 state:D stack:27824 pid:7342 tgid:7336 ppid:6153 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5409 [inline] __schedule+0x17d3/0x4a20 kernel/sched/core.c:6736 __schedule_loop kernel/sched/core.c:6813 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6828 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6885 __mutex_lock_common kernel/locking/mutex.c:684 [inline] __mutex_lock+0x6a4/0xd70 kernel/locking/mutex.c:752 bdev_release+0x1cb/0xa20 block/bdev.c:1028 blkdev_release+0x15/0x20 block/fops.c:628 __fput+0x42b/0x8a0 fs/file_table.c:422 task_work_run+0x251/0x310 kernel/task_work.c:180 get_signal+0x1673/0x1850 kernel/signal.c:2683 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop kernel/entry/common.c:105 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:201 [inline] syscall_exit_to_user_mode+0xc9/0x360 kernel/entry/common.c:212 do_syscall_64+0x10a/0x240 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x6d/0x75 RIP: 0033:0x7fe8b367de69 RSP: 002b:00007fe8b31de0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: 0000000000000000 RBX: 00007fe8b37ac050 RCX: 00007fe8b367de69 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003 RBP: 00007fe8b36ca47a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000006e R14: 00007fe8b37ac050 R15: 00007ffe85f19578 Showing all locks held in the system: 2 locks held by kworker/u8:1/11: 1 lock held by khungtaskd/29: #0: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline] #0: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline] #0: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6614 2 locks held by getty/4827: #0: ffff88802a2cc0a0 (&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 syz-executor.1/5083: 1 lock held by udevd/5145: #0: ffff8880201b94c8 (&disk->open_mutex){+.+.}-{3:3}, at: bdev_open+0xdc/0xc90 block/bdev.c:862 3 locks held by kworker/0:5/5147: #0: ffff888014c74948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3229 [inline] #0: ffff888014c74948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x8e0/0x1770 kernel/workqueue.c:3335 #1: ffffc90008f2fd00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3230 [inline] #1: ffffc90008f2fd00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0x91b/0x1770 kernel/workqueue.c:3335 #2: ffff88806161b240 (&data->fib_lock){+.+.}-{3:3}, at: nsim_fib_event_work+0x2d1/0x4130 drivers/net/netdevsim/fib.c:1489 1 lock held by syz-executor.4/7342: #0: ffff8880201b94c8 (&disk->open_mutex){+.+.}-{3:3}, at: bdev_release+0x1cb/0xa20 block/bdev.c:1028 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 29 Comm: khungtaskd Not tainted 6.8.0-syzkaller-08951-gfe46a7dd189e #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 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:222 [inline] watchdog+0xfb0/0xff0 kernel/hung_task.c:379 kthread+0x2f2/0x390 kernel/kthread.c:388 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 11 Comm: kworker/u8:1 Not tainted 6.8.0-syzkaller-08951-gfe46a7dd189e #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Workqueue: ipv6_addrconf addrconf_dad_work RIP: 0010:lock_is_held_type+0x101/0x190 kernel/locking/lockdep.c:5826 Code: 41 83 fe ff 74 13 31 c0 f6 43 22 03 0f 95 c0 31 db 44 39 f0 0f 94 c3 eb 05 bb 01 00 00 00 48 c7 c7 60 d3 aa 8b e8 af 1a 00 00 ff ff ff ff 65 0f c1 05 02 43 8e 74 83 f8 01 75 44 48 c7 04 24 RSP: 0018:ffffc900000070f8 EFLAGS: 00000082 RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000080000101 RDX: ffff888016eabc00 RSI: ffffffff8baad360 RDI: ffffffff8bfed300 RBP: 0000000000000004 R08: ffffffff8a1e8b9c R09: ffffc900000073f0 R10: ffffc900000073e0 R11: fffff52000000e4a R12: 0000000000000246 R13: ffff888016eabc00 R14: 00000000ffffffff R15: ffffffff8e132020 FS: 0000000000000000(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f86786d35c0 CR3: 000000000df32000 CR4: 0000000000350ef0 Call Trace: __find_rr_leaf+0x395/0x8e0 net/ipv6/route.c:796 find_rr_leaf net/ipv6/route.c:852 [inline] rt6_select net/ipv6/route.c:896 [inline] fib6_table_lookup+0x413/0xbb0 net/ipv6/route.c:2193 ip6_pol_route+0x273/0x15d0 net/ipv6/route.c:2229 pol_lookup_func include/net/ip6_fib.h:614 [inline] fib6_rule_lookup+0x58c/0x790 net/ipv6/fib6_rules.c:116 ip6_route_input_lookup net/ipv6/route.c:2298 [inline] ip6_route_input+0x859/0xd90 net/ipv6/route.c:2594 ip6_rcv_finish+0x144/0x180 net/ipv6/ip6_input.c:77 NF_HOOK+0x3a6/0x450 include/linux/netfilter.h:314 __netif_receive_skb_one_core net/core/dev.c:5538 [inline] __netif_receive_skb+0x1ea/0x6a0 net/core/dev.c:5652 process_backlog+0x39d/0x7a0 net/core/dev.c:5981 __napi_poll+0xcd/0x490 net/core/dev.c:6632 napi_poll net/core/dev.c:6701 [inline] net_rx_action+0x7bb/0x1090 net/core/dev.c:6813 __do_softirq+0x2be/0x943 kernel/softirq.c:554 do_softirq+0x11b/0x1e0 kernel/softirq.c:455 __local_bh_enable_ip+0x1bb/0x200 kernel/softirq.c:382 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:820 [inline] __dev_queue_xmit+0x15fd/0x3b10 net/core/dev.c:4362 dev_queue_xmit include/linux/netdevice.h:3091 [inline] neigh_hh_output include/net/neighbour.h:526 [inline] neigh_output include/net/neighbour.h:540 [inline] ip6_finish_output2+0xfc0/0x1670 net/ipv6/ip6_output.c:137 ip6_finish_output+0x41e/0x810 net/ipv6/ip6_output.c:222 NF_HOOK+0x9e/0x430 include/linux/netfilter.h:314 mld_sendpack+0x838/0xda0 net/ipv6/mcast.c:1818 ipv6_mc_dad_complete+0x88/0x490 net/ipv6/mcast.c:2244 addrconf_dad_completed+0x712/0xcd0 net/ipv6/addrconf.c:4337 addrconf_dad_work+0xdc2/0x16f0 process_one_work kernel/workqueue.c:3254 [inline] process_scheduled_works+0xa02/0x1770 kernel/workqueue.c:3335 worker_thread+0x86d/0xd70 kernel/workqueue.c:3416 kthread+0x2f2/0x390 kernel/kthread.c:388 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243