INFO: task syz.6.4887:22238 blocked for more than 144 seconds. Not tainted 6.13.0-rc6-next-20250107-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.6.4887 state:D stack:24240 pid:22238 tgid:22237 ppid:18155 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5371 [inline] __schedule+0x18f6/0x4cd0 kernel/sched/core.c:6758 __schedule_loop kernel/sched/core.c:6835 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6850 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6907 __mutex_lock_common kernel/locking/mutex.c:662 [inline] __mutex_lock+0x817/0x1010 kernel/locking/mutex.c:730 netfs_writepages+0x12b/0x9e0 fs/netfs/write_issue.c:564 do_writepages+0x35f/0x880 mm/page-writeback.c:2683 filemap_fdatawrite_wbc mm/filemap.c:389 [inline] __filemap_fdatawrite_range mm/filemap.c:422 [inline] __filemap_fdatawrite mm/filemap.c:428 [inline] filemap_fdatawrite+0x1f3/0x2a0 mm/filemap.c:433 v9fs_dir_release+0x151/0x560 fs/9p/vfs_dir.c:219 __fput+0x3e9/0x9f0 fs/file_table.c:450 task_work_run+0x24f/0x310 kernel/task_work.c:227 get_signal+0x15f7/0x1750 kernel/signal.c:2790 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: 0033:0x7f8347b85d29 RSP: 002b:00007f8348aa2038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: 00000000001f0000 RBX: 00007f8347d75fa0 RCX: 00007f8347b85d29 RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000007 RBP: 00007f8347c01b08 R08: 0000000000000000 R09: 0000000000000000 R10: 000000007ffff000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f8347d75fa0 R15: 00007fff2a2c8408 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8e937ee0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e937ee0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e937ee0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6746 2 locks held by getty/5590: #0: ffff88814ce270a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000330b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211 3 locks held by kworker/u8:38/19004: #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3310 #1: ffffc9000bb0fc60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc9000bb0fc60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3310 #2: ffffffff8fcbb6c8 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:281 2 locks held by kworker/u8:42/19008: #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3310 #1: ffffc90004c87c60 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90004c87c60 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3310 3 locks held by kworker/u8:59/19025: 5 locks held by kworker/u8:67/19497: #0: ffff88801baf5948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88801baf5948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3310 #1: ffffc9000c577c60 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc9000c577c60 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3310 #2: ffffffff8fcaf210 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0x16a/0xd50 net/core/net_namespace.c:602 #3: ffffffff8fcbb6c8 (rtnl_mutex){+.+.}-{4:4}, at: cleanup_net+0x6af/0xd50 net/core/net_namespace.c:638 #4: ffffffff8e93d280 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3741 3 locks held by kworker/1:0/19660: #0: ffff88801ac80d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88801ac80d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3310 #1: ffffc9000e7b7c60 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc9000e7b7c60 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3310 #2: ffffffff8fcbb6c8 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104 1 lock held by syz.6.4887/22238: #0: ffff88807c9c8500 (&ctx->wb_lock){+.+.}-{4:4}, at: netfs_writepages+0x12b/0x9e0 fs/netfs/write_issue.c:564 3 locks held by syz.6.4887/22241: #0: ffff88807de82420 (sb_writers#38){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:547 #1: ffff88807c9c8148 (&sb->s_type->i_mutex_key#43){++++}-{4:4}, at: inode_lock include/linux/fs.h:865 [inline] #1: ffff88807c9c8148 (&sb->s_type->i_mutex_key#43){++++}-{4:4}, at: vfs_utimes+0x44d/0x770 fs/utimes.c:65 #2: ffff88807c9c8500 (&ctx->wb_lock){+.+.}-{4:4}, at: netfs_writepages+0xcf/0x9e0 fs/netfs/write_issue.c:558 4 locks held by syz-executor/23420: #0: ffff88803051c420 (sb_writers#8){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3016 [inline] #0: ffff88803051c420 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x225/0xd10 fs/read_write.c:675 #1: ffff888033319c88 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1ea/0x500 fs/kernfs/file.c:325 #2: ffff888027ae0878 (kn->active#49){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x20e/0x500 fs/kernfs/file.c:326 #3: ffffffff8f56b408 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xfc/0x480 drivers/net/netdevsim/bus.c:216 7 locks held by syz-executor/23422: #0: ffff88803051c420 (sb_writers#8){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3016 [inline] #0: ffff88803051c420 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x225/0xd10 fs/read_write.c:675 #1: ffff88806e559c88 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1ea/0x500 fs/kernfs/file.c:325 #2: ffff888027ae0788 (kn->active#50){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x20e/0x500 fs/kernfs/file.c:326 #3: ffffffff8f56b408 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: new_device_store+0x1b4/0x890 drivers/net/netdevsim/bus.c:166 #4: ffff888011d470e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1014 [inline] #4: ffff888011d470e8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x8e/0x520 drivers/base/dd.c:1005 #5: ffff888011d43250 (&devlink->lock_key#21){+.+.}-{4:4}, at: nsim_drv_probe+0xcb/0xb80 drivers/net/netdevsim/dev.c:1537 #6: ffffffff8fcbb6c8 (rtnl_mutex){+.+.}-{4:4}, at: register_nexthop_notifier+0x84/0x290 net/ipv4/nexthop.c:3878 2 locks held by syz-executor/23494: #0: ffffffff901c8850 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff901c8850 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff901c8850 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x22/0x250 net/core/rtnetlink.c:555 #1: ffffffff8fcbb6c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #1: ffffffff8fcbb6c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:326 [inline] #1: ffffffff8fcbb6c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xce2/0x2210 net/core/rtnetlink.c:4011 2 locks held by syz.7.5258/23609: #0: ffff88805ed776c8 (nlk_cb_mutex-ROUTE){+.+.}-{4:4}, at: __netlink_dump_start+0x119/0x790 net/netlink/af_netlink.c:2397 #1: ffffffff8fcbb6c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #1: ffffffff8fcbb6c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dumpit+0x99/0x200 net/core/rtnetlink.c:6770 1 lock held by syz.1.5260/23615: #0: ffffffff8e93d3b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:334 [inline] #0: ffffffff8e93d3b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x451/0x830 kernel/rcu/tree_exp.h:996 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.13.0-rc6-next-20250107-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 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+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 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 UID: 0 PID: 23615 Comm: syz.1.5260 Not tainted 6.13.0-rc6-next-20250107-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:memset_orig+0x29/0xb0 arch/x86/lib/memset_64.S:62 Code: 90 66 0f 1f 00 49 89 fa 40 0f b6 ce 48 b8 01 01 01 01 01 01 01 01 48 0f af c1 41 89 f9 41 83 e1 07 75 70 48 89 d1 48 c1 e9 06 <74> 35 0f 1f 44 00 00 48 ff c9 48 89 07 48 89 47 08 48 89 47 10 48 RSP: 0018:ffffc90004827448 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffffc90004827558 RCX: 0000000000000000 RDX: 0000000000000010 RSI: 0000000000000000 RDI: ffffc90004827570 RBP: dffffc0000000000 R08: ffffc9000482757f R09: 0000000000000000 R10: ffffc90004827570 R11: fffff52000904eb0 R12: ffffc90004828000 R13: ffffc90004827520 R14: ffffffff82143fd3 R15: ffffc90004827570 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055f5dcf0a238 CR3: 000000000e736000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: unwind_next_frame+0xcfb/0x22d0 arch/x86/kernel/unwind_orc.c:592 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122 save_stack+0xfb/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x76/0x430 mm/page_owner.c:297 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1127 [inline] free_frozen_pages+0xe0d/0x10e0 mm/page_alloc.c:2660 vfree+0x1c3/0x360 mm/vmalloc.c:3383 kcov_put kernel/kcov.c:439 [inline] kcov_close+0x28/0x50 kernel/kcov.c:535 __fput+0x3e9/0x9f0 fs/file_table.c:450 task_work_run+0x24f/0x310 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0xa2a/0x28e0 kernel/exit.c:938 do_group_exit+0x207/0x2c0 kernel/exit.c:1087 get_signal+0x16b2/0x1750 kernel/signal.c:3017 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: 0033:0x7ff6b5d85d63 Code: Unable to access opcode bytes at 0x7ff6b5d85d39. RSP: 002b:00007ffec210a788 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: 00007ff6b6bc5000 RBX: 00007ff6b43f76c0 RCX: 00007ff6b5d85d63 RDX: 0000000000000000 RSI: 0000000000021000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 00000000ffffffff R09: 0000000000000000 R10: 0000000000020022 R11: 0000000000000246 R12: 00007ffec210a8e0 R13: ffffffffffffffc0 R14: 0000000000001000 R15: 0000000000000000