INFO: task syz-executor:4244 blocked for more than 144 seconds. Not tainted 6.1.116-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:20632 pid:4244 ppid:1 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5241 [inline] __schedule+0x143f/0x4570 kernel/sched/core.c:6558 schedule+0xbf/0x180 kernel/sched/core.c:6634 wb_wait_for_completion+0x162/0x290 fs/fs-writeback.c:191 sync_inodes_sb+0x28f/0xb10 fs/fs-writeback.c:2739 sync_filesystem+0x16b/0x220 fs/sync.c:64 generic_shutdown_super+0x6b/0x340 fs/super.c:474 kill_block_super+0x7a/0xe0 fs/super.c:1470 deactivate_locked_super+0xa0/0x110 fs/super.c:332 cleanup_mnt+0x490/0x520 fs/namespace.c:1186 task_work_run+0x246/0x300 kernel/task_work.c:203 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xde/0x100 kernel/entry/common.c:177 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:303 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fade377fa47 RSP: 002b:00007ffd5cf66c98 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007fade37f123c RCX: 00007fade377fa47 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd5cf66d50 RBP: 00007ffd5cf66d50 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffd5cf67dd0 R13: 00007fade37f123c R14: 000000000001963e R15: 00007ffd5cf67e10 Showing all locks held in the system: 5 locks held by kworker/u4:1/11: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8d32b110 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:517 1 lock held by rcu_tasks_trace/13: #0: ffffffff8d32b910 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:517 1 lock held by khungtaskd/27: #0: ffffffff8d32af40 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8d32af40 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8d32af40 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6510 1 lock held by dhcpcd/3915: #0: ffffffff8e4fb568 ( rtnl_mutex ){+.+.}-{3:3}, at: devinet_ioctl+0x2a5/0x1ae0 net/ipv4/devinet.c:1081 2 locks held by getty/4006: #0: ffff88803181c098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc900032462f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a7/0x1db0 drivers/tty/n_tty.c:2198 2 locks held by syz-executor/4244: #0: ffff888078d600e0 (&type->s_umount_key#66){+.+.}-{3:3}, at: deactivate_super+0xa9/0xe0 fs/super.c:362 #1: ffff8880255ce7d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline] #1: ffff8880255ce7d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x270/0xb10 fs/fs-writeback.c:2737 3 locks held by kworker/0:5/4291: #0: ffff8880308f8138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267 #1: ffffc9000434fd20 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267 #2: ffffffff8e4fb568 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xcc/0x16b0 net/ipv6/addrconf.c:4115 5 locks held by kworker/u4:17/4644: #0: ffff888017e16938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267 #1: ffffc90005e8fd20 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267 #2: ffffffff8e4ef1d0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0xf1/0xb60 net/core/net_namespace.c:566 #3: ffffffff8e4fb568 (rtnl_mutex){+.+.}-{3:3}, at: sit_exit_batch_net+0xc0/0x480 net/ipv6/sit.c:1883 #4: ffffffff8d330538 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline] #4: ffffffff8d330538 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x4f0/0x930 kernel/rcu/tree_exp.h:962 4 locks held by kworker/u4:18/4690: 2 locks held by kworker/1:9/4878: #0: ffff888017c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267 #1: ffffc9000360fd20 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267 3 locks held by kworker/1:15/4884: #0: ffff8880308f8138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267 #1: ffffc9000366fd20 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267 #2: ffffffff8e4fb568 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xcc/0x16b0 net/ipv6/addrconf.c:4115 1 lock held by syz-executor/5550: #0: ffffffff8e4fb568 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline] ffffffff8e4fb568 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7c1/0xff0 net/core/rtnetlink.c:6147 1 lock held by syz-executor/5938: #0: ffffffff8e4fb568 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline] #0: ffffffff8e4fb568 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7c1/0xff0 net/core/rtnetlink.c:6147 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted 6.1.116-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 nmi_cpu_backtrace+0x4e1/0x560 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1ae/0x3f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline] watchdog+0xf88/0xfd0 kernel/hung_task.c:377 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 4631 Comm: kworker/u4:16 Not tainted 6.1.116-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:hlock_class kernel/locking/lockdep.c:228 [inline] RIP: 0010:check_wait_context kernel/locking/lockdep.c:4748 [inline] RIP: 0010:__lock_acquire+0x794/0x1f80 kernel/locking/lockdep.c:4999 Code: 8b 5d 00 81 e3 ff 1f 00 00 48 89 d8 48 c1 e8 06 48 8d 3c c5 60 12 23 91 be 08 00 00 00 e8 74 76 77 00 48 0f a3 1d 9c 72 b8 0f <73> 1b 48 8d 04 5b 48 c1 e0 06 48 8d 98 20 91 bb 90 48 ba 00 00 00 RSP: 0018:ffffc90005f9f620 EFLAGS: 00000057 RAX: 0000000000000001 RBX: 0000000000000742 RCX: ffffffff816a9fbc RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff91231348 RBP: ffff888027dca938 R08: dffffc0000000000 R09: fffffbfff224626a R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000003 R13: ffff888027dca938 R14: 0000000000000003 R15: 0000000000000003 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020404030 CR3: 000000000d08e000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 local_lock_acquire include/linux/local_lock_internal.h:29 [inline] crng_make_state+0x226/0xb50 drivers/char/random.c:328 _get_random_bytes+0xd3/0x2b0 drivers/char/random.c:366 nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:776 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline] nsim_dev_trap_report_work+0x628/0xab0 drivers/net/netdevsim/dev.c:851 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 vkms_vblank_simulate: vblank timer overrun vkms_vblank_simulate: vblank timer overrun