INFO: task syz-executor.2:11674 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 D26856 11674 8158 0x00000004 Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x887/0x2040 kernel/sched/core.c:3517 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: 0033:0x7efdfb7ef639 Code: Bad RIP value. RSP: 002b:00007efdf9d62168 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007efdfb90ff80 RCX: 00007efdfb7ef639 RDX: 0000000020000100 RSI: 0000000020000080 RDI: 0000000000000000 RBP: 00007efdfb84aae9 R08: 0000000020000180 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fff4cae86df R14: 00007efdf9d62300 R15: 0000000000022000 Showing all locks held in the system: 3 locks held by kworker/0:1/14: #0: 00000000faae5630 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124 #1: 00000000a2747e32 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128 #2: 0000000064dad506 (rtnl_mutex){+.+.}, at: addrconf_dad_work+0x9c/0x10a0 net/ipv6/addrconf.c:3989 2 locks held by kworker/1:1/33: #0: 00000000c06718f4 ((wq_completion)"events"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124 #1: 000000007d6c846c ((work_completion)(&m->wq)){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128 3 locks held by kworker/u4:2/75: #0: 00000000dab6b40b ((wq_completion)"%s""netns"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124 #1: 000000009181260c (net_cleanup_work){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128 audit: type=1804 audit(1668914103.363:131): pid=20032 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.4" name="/root/syzkaller-testdir358498157/syzkaller.EMY7ko/369/file1/bus" dev="loop4" ino=42 res=1 #2: 000000007070b64b (pernet_ops_rwsem){++++}, at: cleanup_net+0xa8/0x8b0 net/core/net_namespace.c:521 1 lock held by khungtaskd/1570: #0: 00000000f22db626 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4441 attempt to access beyond end of device 1 lock held by in:imklog/7805: loop4: rw=2049, want=92, limit=87 #0: 000000008ddd36a9 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x26f/0x310 fs/file.c:767 Buffer I/O error on dev loop4, logical block 45, lost async page write 2 locks held by kworker/1:44/19764: #0: 00000000667f7d63 ((wq_completion)"rcu_gp"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124 #1: 00000000b40efe98 ((work_completion)(&rew.rew_work)){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128 attempt to access beyond end of device 3 locks held by kworker/1:46/19772: loop4: rw=2049, want=94, limit=87 Buffer I/O error on dev loop4, logical block 46, lost async page write #0: 00000000c06718f4 ((wq_completion)"events"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124 #1: 00000000c4ce90d1 ((linkwatch_work).work){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128 #2: 0000000064dad506 (rtnl_mutex){+.+.}, at: linkwatch_event+0xb/0x60 net/core/link_watch.c:236 2 locks held by syz-executor.5/19935: #0: 0000000064dad506 (rtnl_mutex){+.+.}, at: tun_detach drivers/net/tun.c:759 [inline] #0: 0000000064dad506 (rtnl_mutex){+.+.}, at: tun_chr_close+0x3a/0x180 drivers/net/tun.c:3323 #1: 00000000a0c9d498 (rcu_preempt_state.exp_mutex){+.+.}, at: exp_funnel_lock kernel/rcu/tree_exp.h:297 [inline] #1: 00000000a0c9d498 (rcu_preempt_state.exp_mutex){+.+.}, at: _synchronize_rcu_expedited+0x4dc/0x6f0 kernel/rcu/tree_exp.h:667 1 lock held by syz-executor.1/19965: #0: 0000000064dad506 (rtnl_mutex){+.+.}, at: do_ipv6_setsockopt.constprop.0+0x2c1/0x3ed0 net/ipv6/ipv6_sockglue.c:166 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1570 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: 4694 Comm: systemd-journal Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 RIP: 0010:__read_once_size include/linux/compiler.h:263 [inline] RIP: 0010:ep_busy_loop fs/eventpoll.c:401 [inline] RIP: 0010:ep_poll+0x50f/0xcb0 fs/eventpoll.c:1772 Code: b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 0f b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 09 84 d2 74 05 e8 e1 73 e3 ff <44> 8b b3 58 01 00 00 bf 08 00 00 00 44 89 f6 e8 dd 98 ad ff 41 83 RSP: 0018:ffff8880a0f7fcf0 EFLAGS: 00000246 RAX: 0000000000000003 RBX: ffff8880a0fa2c80 RCX: ffffffff81b4ec79 RDX: 0000000000000000 RSI: ffffffff81b4edbd RDI: ffff8880a0fa2dd8 RBP: ffff8880a0f7feb0 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000005 R11: 0000000000000000 R12: ffff8880a0fa2d90 R13: ffff8880a0fa2d00 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f265374b8c0(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2650c49000 CR3: 00000000a17b0000 CR4: 00000000003406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: do_epoll_wait+0x1aa/0x200 fs/eventpoll.c:2190 __do_sys_epoll_wait fs/eventpoll.c:2200 [inline] __se_sys_epoll_wait fs/eventpoll.c:2197 [inline] __x64_sys_epoll_wait+0x93/0xf0 fs/eventpoll.c:2197 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f2652a142e3 Code: 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 83 3d 29 54 2b 00 00 75 13 49 89 ca b8 e8 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 34 c3 48 83 ec 08 e8 0b c2 00 00 48 89 04 24 RSP: 002b:00007fffcdd01f38 EFLAGS: 00000246 ORIG_RAX: 00000000000000e8 RAX: ffffffffffffffda RBX: 0000562639b121e0 RCX: 00007f2652a142e3 RDX: 0000000000000013 RSI: 00007fffcdd01f40 RDI: 0000000000000008 RBP: 00007fffcdd02130 R08: 00007fffcdd29000 R09: 000000583560668f R10: 00000000ffffffff R11: 0000000000000246 R12: 00007fffcdd01f40 R13: 0000000000000001 R14: ffffffffffffffff R15: 0005edde584fa67a