INFO: task syz.8.1718:11433 blocked for more than 144 seconds. Not tainted 6.13.0-syzkaller-00164-g100ceb4817a2 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.8.1718 state:D stack:23888 pid:11433 tgid:11430 ppid:10155 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0x17fb/0x4be0 kernel/sched/core.c:6756 __schedule_loop kernel/sched/core.c:6833 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6848 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6905 __mutex_lock_common kernel/locking/mutex.c:665 [inline] __mutex_lock+0x7e7/0xee0 kernel/locking/mutex.c:735 netfs_writepages+0x12b/0x9e0 fs/netfs/write_issue.c:564 do_writepages+0x35f/0x880 mm/page-writeback.c:2708 filemap_fdatawrite_wbc mm/filemap.c:388 [inline] __filemap_fdatawrite_range mm/filemap.c:421 [inline] __filemap_fdatawrite mm/filemap.c:427 [inline] filemap_fdatawrite+0x1f3/0x2a0 mm/filemap.c:432 v9fs_dir_release+0x151/0x560 fs/9p/vfs_dir.c:219 __fput+0x23c/0xa50 fs/file_table.c:450 task_work_run+0x24f/0x310 kernel/task_work.c:239 get_signal+0x15f7/0x1750 kernel/signal.c:2809 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xce/0x340 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f24d0985d29 RSP: 002b:00007f24d183f038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: 000000000068c000 RBX: 00007f24d0b75fa0 RCX: 00007f24d0985d29 RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000007 RBP: 00007f24d0a01b08 R08: 0000000000000000 R09: 0000000000000000 R10: 000000007ffff000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f24d0b75fa0 R15: 00007fffda6a3878 Showing all locks held in the system: 3 locks held by kworker/u8:1/12: #0: ffff8880310dd948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff8880310dd948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3317 #1: ffffc90000117d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc90000117d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3317 #2: ffffffff8fca7ec8 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0xd0/0x16f0 net/ipv6/addrconf.c:4215 1 lock held by khungtaskd/30: #0: ffffffff8e937da0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e937da0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e937da0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6744 3 locks held by kworker/u8:5/1806: #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3317 #1: ffffc90004e5fd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc90004e5fd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3317 #2: ffffffff8fca7ec8 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:285 2 locks held by getty/5578: #0: ffff888031ffe0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000331b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211 2 locks held by kworker/u8:14/8474: #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3317 #1: ffffc900036f7d00 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc900036f7d00 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3317 1 lock held by syz.8.1718/11433: #0: ffff8880782f9ec0 (&ctx->wb_lock){+.+.}-{4:4}, at: netfs_writepages+0x12b/0x9e0 fs/netfs/write_issue.c:564 1 lock held by syz.8.1718/11441: #0: ffff8880782f9ec0 (&ctx->wb_lock){+.+.}-{4:4}, at: netfs_writepages+0xcf/0x9e0 fs/netfs/write_issue.c:558 2 locks held by syz.9.2104/12851: #0: ffffffff8fca7ec8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8fca7ec8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:128 [inline] #0: ffffffff8fca7ec8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dellink+0x394/0x8d0 net/core/rtnetlink.c:3510 #1: ffffffff8e93d2b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:297 [inline] #1: ffffffff8e93d2b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x381/0x830 kernel/rcu/tree_exp.h:976 1 lock held by syz.7.2109/12855: #0: ffffffff8fca7ec8 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:698 [inline] #0: ffffffff8fca7ec8 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3b/0x1b0 drivers/net/tun.c:3517 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.13.0-syzkaller-00164-g100ceb4817a2 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 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:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:234 [inline] watchdog+0xff6/0x1040 kernel/hung_task.c:397 kthread+0x2f0/0x390 kernel/kthread.c:389 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 8480 Comm: kworker/u8:17 Not tainted 6.13.0-syzkaller-00164-g100ceb4817a2 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:__lock_release kernel/locking/lockdep.c:5533 [inline] RIP: 0010:lock_release+0x2ac/0xa30 kernel/locking/lockdep.c:5870 Code: 56 47 0a 89 5c 24 44 89 da 85 c0 0f 84 f0 01 00 00 4d 85 f6 0f 84 1b 03 00 00 49 8d 5e 24 48 89 d8 48 c1 e8 03 42 0f b6 04 38 <84> c0 0f 85 2a 05 00 00 83 3b 00 0f 85 2d 04 00 00 4d 8d 66 20 4c RSP: 0018:ffffc900033b7780 EFLAGS: 00000803 RAX: 0000000000000000 RBX: ffff88807841c7a4 RCX: ffffc900033b7803 RDX: 0000000000000004 RSI: ffff8880b8646a60 RDI: ffff88807841c780 RBP: ffffc900033b78a8 R08: ffffffff9018d4f7 R09: 1ffffffff2031a9e R10: dffffc0000000000 R11: fffffbfff2031a9f R12: 0000000000000014 R13: 0000000000000004 R14: ffff88807841c780 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555587a895c8 CR3: 000000000e736000 CR4: 00000000003526f0 DR0: 0000000000002800 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: local_lock_release include/linux/local_lock_internal.h:38 [inline] ___slab_alloc+0xa06/0x14a0 mm/slub.c:3740 __slab_alloc+0x58/0xa0 mm/slub.c:3920 __slab_alloc_node mm/slub.c:3995 [inline] slab_alloc_node mm/slub.c:4156 [inline] kmem_cache_alloc_node_noprof+0x269/0x380 mm/slub.c:4220 __alloc_skb+0x1c3/0x440 net/core/skbuff.c:668 alloc_skb include/linux/skbuff.h:1323 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:748 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline] nsim_dev_trap_report_work+0x261/0xb50 drivers/net/netdevsim/dev.c:851 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3317 worker_thread+0x870/0xd30 kernel/workqueue.c:3398 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 vkms_vblank_simulate: vblank timer overrun