INFO: task syz.8.2636:17813 blocked for more than 143 seconds. Not tainted 6.13.0-syzkaller-00603-g3d3a9c8b89d4 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.8.2636 state:D stack:23472 pid:17813 tgid:17811 ppid:12873 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0x1850/0x4c30 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+0x361/0x880 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+0x23e/0xa50 fs/file_table.c:450 task_work_run+0x251/0x310 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: 0033:0x7efc17d85d29 RSP: 002b:00007efc18c39038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: 0000000000328000 RBX: 00007efc17f75fa0 RCX: 00007efc17d85d29 RDX: 0000000000000000 RSI: 000000000000000a RDI: 0000000000000009 RBP: 00007efc17e01b08 R08: 0000000000000000 R09: 0000000000000000 R10: 000000007ffff000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007efc17f75fa0 R15: 00007fffd6a20568 Showing all locks held in the system: 3 locks held by kworker/u8:0/11: #0: ffff88814ccd1148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff88814ccd1148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3317 #1: ffffc90000107d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc90000107d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3317 #2: ffffffff8fcc0188 (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 2 locks held by kworker/u8:5/135: #0: ffff88801ac81148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff88801ac81148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3317 #1: ffffc90002e67d00 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc90002e67d00 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3317 1 lock held by dhcpcd/5493: #0: ffffffff8fcc0188 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:128 [inline] #0: ffffffff8fcc0188 (rtnl_mutex){+.+.}-{4:4}, at: devinet_ioctl+0x31a/0x1ac0 net/ipv4/devinet.c:1129 2 locks held by getty/5585: #0: ffff8880314f30a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211 2 locks held by kworker/u9:5/5846: #0: ffff88802565b148 ((wq_completion)nbd0-recv){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff88802565b148 ((wq_completion)nbd0-recv){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3317 #1: ffffc90003e1fd00 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc90003e1fd00 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3317 5 locks held by kworker/u8:18/10978: #0: ffff88801baed948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff88801baed948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3317 #1: ffffc9000414fd00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc9000414fd00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3317 #2: ffffffff8fcb3cd0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0x16a/0xd50 net/core/net_namespace.c:602 #3: ffffffff8fcc0188 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch+0xe9/0xaa0 net/core/dev.c:12078 #4: ffffffff8e93d2b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:297 [inline] #4: ffffffff8e93d2b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x381/0x830 kernel/rcu/tree_exp.h:976 1 lock held by syz.8.2636/17813: #0: ffff8880787d8b70 (&ctx->wb_lock){+.+.}-{4:4}, at: netfs_writepages+0x12b/0x9e0 fs/netfs/write_issue.c:564 1 lock held by syz.8.2636/17817: #0: ffff8880787d8b70 (&ctx->wb_lock){+.+.}-{4:4}, at: netfs_writepages+0xcf/0x9e0 fs/netfs/write_issue.c:558 1 lock held by syz-executor/18595: #0: ffffffff8fcc0188 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8fcc0188 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:326 [inline] #0: ffffffff8fcc0188 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xce2/0x2210 net/core/rtnetlink.c:4011 2 locks held by syz-executor/18646: #0: ffffffff8f469780 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8f469780 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8f469780 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x22/0x250 net/core/rtnetlink.c:555 #1: ffffffff8fcc0188 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #1: ffffffff8fcc0188 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:326 [inline] #1: ffffffff8fcc0188 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xce2/0x2210 net/core/rtnetlink.c:4011 2 locks held by syz-executor/18824: #0: ffffffff901c4898 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff901c4898 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff901c4898 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x22/0x250 net/core/rtnetlink.c:555 #1: ffffffff8fcc0188 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #1: ffffffff8fcc0188 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:326 [inline] #1: ffffffff8fcc0188 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xce2/0x2210 net/core/rtnetlink.c:4011 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.13.0-syzkaller-00603-g3d3a9c8b89d4 #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+0x2f2/0x390 kernel/kthread.c:389 ret_from_fork+0x4d/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 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline] NMI backtrace for cpu 0 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:106 [inline] NMI backtrace for cpu 0 skipped: idling at acpi_safe_halt+0x21/0x30 drivers/acpi/processor_idle.c:111