INFO: task syz-executor.2:16472 blocked for more than 140 seconds. Not tainted 4.19.211-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D28416 16472 8241 0x00000004 IPVS: ftp: loaded support on port[0] = 21 New replicast peer: fe80:0000:0000:0000:0000:0000:0000:0000 Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x887/0x2040 kernel/sched/core.c:3517 Enabled bearer , priority 10 Disabling bearer schedule+0x8d/0x1b0 kernel/sched/core.c:3561 schedule_timeout+0x92d/0xfe0 kernel/time/timer.c:1794 do_wait_for_common kernel/sched/completion.c:83 [inline] __wait_for_common kernel/sched/completion.c:104 [inline] wait_for_common+0x29c/0x470 kernel/sched/completion.c:115 __flush_work+0x4bb/0x8b0 kernel/workqueue.c:2926 __cancel_work_timer+0x412/0x590 kernel/workqueue.c:3013 p9_conn_destroy net/9p/trans_fd.c:904 [inline] p9_fd_close+0x305/0x520 net/9p/trans_fd.c:934 p9_client_create+0x901/0x12e0 net/9p/client.c:1084 v9fs_session_init+0x1dd/0x1770 fs/9p/v9fs.c:421 v9fs_mount+0x73/0x910 fs/9p/vfs_super.c:135 mount_fs+0xa3/0x310 fs/super.c:1261 vfs_kern_mount.part.0+0x68/0x470 fs/namespace.c:961 vfs_kern_mount fs/namespace.c:951 [inline] do_new_mount fs/namespace.c:2492 [inline] do_mount+0x115c/0x2f50 fs/namespace.c:2822 ksys_mount+0xcf/0x130 fs/namespace.c:3038 __do_sys_mount fs/namespace.c:3052 [inline] __se_sys_mount fs/namespace.c:3049 [inline] __x64_sys_mount+0xba/0x150 fs/namespace.c:3049 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7fe179405639 Code: Bad RIP value. RSP: 002b:00007fe177936168 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fe179526120 RCX: 00007fe179405639 RDX: 0000000020000100 RSI: 0000000020000080 RDI: 0000000000000000 RBP: 00007fe179460ae9 R08: 0000000020000180 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fff95dba19f R14: 00007fe177936300 R15: 0000000000022000 Showing all locks held in the system: 1 lock held by khungtaskd/1540: #0: 0000000012c7c8ad (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4441 2 locks held by kworker/1:2/3688: #0: 00000000d32cf4d5 ((wq_completion)"events"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124 #1: 000000000ca70f9b ((work_completion)(&m->wq)){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128 3 locks held by systemd-udevd/4697: #0: 00000000ab07d12c (&bdev->bd_mutex){+.+.}, at: __blkdev_get+0x1d0/0x1480 fs/block_dev.c:1478 IPVS: ftp: loaded support on port[0] = 21 #1: 000000007de962fe (&(&zone->lock)->rlock){..-.}, at: spin_lock include/linux/spinlock.h:329 [inline] #1: 000000007de962fe (&(&zone->lock)->rlock){..-.}, at: free_one_page+0x31/0x10b0 mm/page_alloc.c:1196 #2: 00000000bb28914e (&rq->lock){-.-.}, at: rq_lock kernel/sched/sched.h:1826 [inline] #2: 00000000bb28914e (&rq->lock){-.-.}, at: __schedule+0x1f9/0x2040 kernel/sched/core.c:3455 New replicast peer: fe80:0000:0000:0000:0000:0000:0000:0000 1 lock held by in:imklog/7825: Enabled bearer , priority 10 #0: 00000000e5d2c536 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x26f/0x310 fs/file.c:767 Disabling bearer 3 locks held by kworker/1:4/9370: #0: 00000000d32cf4d5 ((wq_completion)"events"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124 #1: 0000000040ef63db ((work_completion)(&ub->work)){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128 #2: 00000000bf222a92 (rcu_preempt_state.exp_mutex){+.+.}, at: exp_funnel_lock kernel/rcu/tree_exp.h:329 [inline] #2: 00000000bf222a92 (rcu_preempt_state.exp_mutex){+.+.}, at: _synchronize_rcu_expedited+0x256/0x6f0 kernel/rcu/tree_exp.h:667 3 locks held by kworker/u4:7/9490: #0: 000000004d05b22c ((wq_completion)"%s""netns"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124 #1: 00000000c1e7232a (net_cleanup_work){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128 #2: 00000000fd286b63 (pernet_ops_rwsem){++++}, at: cleanup_net+0xa8/0x8b0 net/core/net_namespace.c:521 2 locks held by kworker/1:5/16821: #0: 000000000eeae328 ((wq_completion)"rcu_gp"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124 #1: 000000007d521704 ((work_completion)(&rew.rew_work)){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128 1 lock held by syz-executor.0/20602: #0: 00000000bf222a92 (rcu_preempt_state.exp_mutex){+.+.}, at: exp_funnel_lock kernel/rcu/tree_exp.h:297 [inline] #0: 00000000bf222a92 (rcu_preempt_state.exp_mutex){+.+.}, at: _synchronize_rcu_expedited+0x4dc/0x6f0 kernel/rcu/tree_exp.h:667 1 lock held by syz-executor.3/25164: #0: 000000000dc4ac76 (rtnl_mutex){+.+.}, at: ppp_release+0x11d/0x1e0 drivers/net/ppp/ppp_generic.c:407 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1540 Comm: khungtaskd Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1fc/0x2ef lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x63/0xa2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1a6/0x1f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline] watchdog+0x991/0xe60 kernel/hung_task.c:287 kthread+0x33f/0x460 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 1037 Comm: kworker/u4:4 Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Workqueue: bat_events batadv_nc_worker RIP: 0010:write_comp_data+0x23/0x70 kernel/kcov.c:122 Code: 1f 84 00 00 00 00 00 49 89 f1 49 89 fa 65 48 8b 34 25 c0 df 01 00 65 8b 05 7a 59 9f 7e a9 00 01 1f 00 75 4f 8b 86 60 13 00 00 <83> f8 03 75 44 48 8b 86 68 13 00 00 8b b6 64 13 00 00 48 8b 38 48 RSP: 0018:ffff8880b3b97ca8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffff888098b11928 RCX: ffffffff87d8f32a RDX: 0000000000000001 RSI: ffff8880b3b7e380 RDI: 0000000000000001 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000 R13: dffffc0000000000 R14: 000000000000003d R15: ffff8880a555d400 FS: 0000000000000000(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c01ce46000 CR3: 00000000af389000 CR4: 00000000003426f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_read_lock include/linux/rcupdate.h:628 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:419 [inline] batadv_nc_worker+0x8fa/0xd50 net/batman-adv/network-coding.c:730 process_one_work+0x864/0x1570 kernel/workqueue.c:2153 worker_thread+0x64c/0x1130 kernel/workqueue.c:2296 kthread+0x33f/0x460 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 IPVS: ftp: loaded support on port[0] = 21 New replicast peer: fe80:0000:0000:0000:0000:0000:0000:0000 Enabled bearer , priority 10 Disabling bearer