INFO: task kworker/u4:19:15077 blocked for more than 143 seconds. Not tainted 5.5.0-rc5-next-20200107-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/u4:19 D24472 15077 2 0x80004000 Workqueue: netns cleanup_net Call Trace: context_switch kernel/sched/core.c:3385 [inline] __schedule+0x934/0x1f90 kernel/sched/core.c:4081 schedule+0xdc/0x2b0 kernel/sched/core.c:4155 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:4214 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x7ab/0x13c0 kernel/locking/mutex.c:1103 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1118 nfnl_lock+0x24/0x30 net/netfilter/nfnetlink.c:62 ip_set_net_exit+0x19d/0x5c0 net/netfilter/ipset/ip_set_core.c:2385 ops_exit_list.isra.0+0xb1/0x160 net/core/net_namespace.c:172 cleanup_net+0x538/0xaf0 net/core/net_namespace.c:597 process_one_work+0x9af/0x1740 kernel/workqueue.c:2264 worker_thread+0x98/0xe40 kernel/workqueue.c:2410 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 INFO: task syz-executor.2:8690 can't die for more than 143 seconds. syz-executor.2 D26648 8690 9564 0x80004006 Call Trace: context_switch kernel/sched/core.c:3385 [inline] __schedule+0x934/0x1f90 kernel/sched/core.c:4081 schedule+0xdc/0x2b0 kernel/sched/core.c:4155 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:4214 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x7ab/0x13c0 kernel/locking/mutex.c:1103 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1118 nfnl_lock+0x24/0x30 net/netfilter/nfnetlink.c:62 ip_set_net_exit+0x19d/0x5c0 net/netfilter/ipset/ip_set_core.c:2385 ops_exit_list.isra.0+0xb1/0x160 net/core/net_namespace.c:172 setup_net+0x546/0x8b0 net/core/net_namespace.c:358 copy_net_ns+0x29e/0x5a0 net/core/net_namespace.c:476 create_new_namespaces+0x400/0x860 kernel/nsproxy.c:103 unshare_nsproxy_namespaces+0xc2/0x200 kernel/nsproxy.c:202 ksys_unshare+0x444/0x980 kernel/fork.c:2935 __do_sys_unshare kernel/fork.c:3003 [inline] __se_sys_unshare kernel/fork.c:3001 [inline] __x64_sys_unshare+0x31/0x40 kernel/fork.c:3001 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45af49 Code: Bad RIP value. RSP: 002b:00007fbeffb55c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 000000000045af49 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000060000000 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fbeffb566d4 R13: 00000000004cc492 R14: 00000000004e7350 R15: 00000000ffffffff INFO: task syz-executor.2:8690 blocked for more than 144 seconds. Not tainted 5.5.0-rc5-next-20200107-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D26648 8690 9564 0x80004006 Call Trace: context_switch kernel/sched/core.c:3385 [inline] __schedule+0x934/0x1f90 kernel/sched/core.c:4081 schedule+0xdc/0x2b0 kernel/sched/core.c:4155 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:4214 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x7ab/0x13c0 kernel/locking/mutex.c:1103 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1118 nfnl_lock+0x24/0x30 net/netfilter/nfnetlink.c:62 ip_set_net_exit+0x19d/0x5c0 net/netfilter/ipset/ip_set_core.c:2385 ops_exit_list.isra.0+0xb1/0x160 net/core/net_namespace.c:172 setup_net+0x546/0x8b0 net/core/net_namespace.c:358 copy_net_ns+0x29e/0x5a0 net/core/net_namespace.c:476 create_new_namespaces+0x400/0x860 kernel/nsproxy.c:103 unshare_nsproxy_namespaces+0xc2/0x200 kernel/nsproxy.c:202 ksys_unshare+0x444/0x980 kernel/fork.c:2935 __do_sys_unshare kernel/fork.c:3003 [inline] __se_sys_unshare kernel/fork.c:3001 [inline] __x64_sys_unshare+0x31/0x40 kernel/fork.c:3001 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45af49 Code: Bad RIP value. RSP: 002b:00007fbeffb55c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 000000000045af49 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000060000000 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fbeffb566d4 R13: 00000000004cc492 R14: 00000000004e7350 R15: 00000000ffffffff INFO: task syz-executor.3:8773 can't die for more than 144 seconds. syz-executor.3 R running task 25848 8773 9566 0x00004006 Call Trace: mark_held_locks+0xa4/0xf0 kernel/locking/lockdep.c:3359 Showing all locks held in the system: 1 lock held by khungtaskd/1133: #0: ffffffff89bae280 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x279 kernel/locking/lockdep.c:5333 1 lock held by rsyslogd/9426: #0: ffff8880a47220e0 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:803 2 locks held by getty/9517: #0: ffff88809534d090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc9000594b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/9518: #0: ffff8880a10ec090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc900058eb2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/9519: #0: ffff8880a120c090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc900058db2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/9520: #0: ffff88809b9c5090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc9000591b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/9521: #0: ffff8880a76d5090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc9000593b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/9522: #0: ffff888093e09090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc900056db2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 4 locks held by kworker/u4:19/15077: #0: ffff8880a9b26528 ((wq_completion)netns){+.+.}, at: __write_once_size include/linux/compiler.h:250 [inline] #0: ffff8880a9b26528 ((wq_completion)netns){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8880a9b26528 ((wq_completion)netns){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:869 [inline] #0: ffff8880a9b26528 ((wq_completion)netns){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff8880a9b26528 ((wq_completion)netns){+.+.}, at: set_work_data kernel/workqueue.c:615 [inline] #0: ffff8880a9b26528 ((wq_completion)netns){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:642 [inline] #0: ffff8880a9b26528 ((wq_completion)netns){+.+.}, at: process_one_work+0x88b/0x1740 kernel/workqueue.c:2235 #1: ffffc900065ffdc0 (net_cleanup_work){+.+.}, at: process_one_work+0x8c1/0x1740 kernel/workqueue.c:2239 #2: ffffffff8a7295c8 (pernet_ops_rwsem){++++}, at: cleanup_net+0xae/0xaf0 net/core/net_namespace.c:559 #3: ffffffff8c3e0e10 (&table[i].mutex){+.+.}, at: nfnl_lock+0x24/0x30 net/netfilter/nfnetlink.c:62 2 locks held by getty/6611: #0: ffff88804c99f090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc9000515b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by syz-executor.2/8690: #0: ffffffff8a7295c8 (pernet_ops_rwsem){++++}, at: copy_net_ns+0x27b/0x5a0 net/core/net_namespace.c:472 #1: ffffffff8c3e0e10 (&table[i].mutex){+.+.}, at: nfnl_lock+0x24/0x30 net/netfilter/nfnetlink.c:62 2 locks held by syz-executor.3/8773: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1133 Comm: khungtaskd Not tainted 5.5.0-rc5-next-20200107-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x197/0x210 lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x70/0xb2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x23b/0x28b lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:249 [inline] watchdog+0xdf1/0x14e0 kernel/hung_task.c:333 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 8773 Comm: syz-executor.3 Not tainted 5.5.0-rc5-next-20200107-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:find_held_lock+0x1/0x130 kernel/locking/lockdep.c:4050 Code: 00 48 8b 75 d0 e9 91 fc ff ff 4c 89 f7 48 89 75 d0 e8 c3 cc 58 00 48 8b 75 d0 e9 08 fd ff ff 66 2e 0f 1f 84 00 00 00 00 00 55 <48> 89 e5 41 57 44 8d 7a ff 41 56 49 89 f6 49 63 c7 41 55 48 8d 04 RSP: 0018:ffffc900085d6f90 EFLAGS: 00000006 RAX: 0000000000000000 RBX: 1ffff920010badf9 RCX: ffffc900085d7008 RDX: 0000000000000003 RSI: ffffffff89bae280 RDI: ffff8880555b2600 RBP: ffffc900085d7070 R08: 0000000000000003 R09: ffff8880555b2e98 R10: fffffbfff1547b20 R11: ffffffff8aa3d907 R12: ffffffff89bae280 R13: ffffffff868e0364 R14: ffffc900085d7048 R15: ffff8880555b2600 FS: 00007ff47b608700(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000010387b0 CR3: 000000003df4d000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: rcu_lock_release include/linux/rcupdate.h:213 [inline] rcu_read_unlock include/linux/rcupdate.h:655 [inline] cond_resched_rcu include/linux/sched.h:1811 [inline] hash_mac4_list+0x296/0xe40 net/netfilter/ipset/ip_set_hash_gen.h:1133 ip_set_dump_start+0x96c/0x1ca0 net/netfilter/ipset/ip_set_core.c:1632 netlink_dump+0x558/0xfb0 net/netlink/af_netlink.c:2244 __netlink_dump_start+0x66a/0x930 net/netlink/af_netlink.c:2352 netlink_dump_start include/linux/netlink.h:233 [inline] ip_set_dump+0x15a/0x1d0 net/netfilter/ipset/ip_set_core.c:1690 nfnetlink_rcv_msg+0xcf2/0xfb0 net/netfilter/nfnetlink.c:229 netlink_rcv_skb+0x177/0x450 net/netlink/af_netlink.c:2477 nfnetlink_rcv+0x1ba/0x460 net/netfilter/nfnetlink.c:563 netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline] netlink_unicast+0x58c/0x7d0 net/netlink/af_netlink.c:1328 netlink_sendmsg+0x91c/0xea0 net/netlink/af_netlink.c:1917 sock_sendmsg_nosec net/socket.c:643 [inline] sock_sendmsg+0xd7/0x130 net/socket.c:663 ____sys_sendmsg+0x753/0x880 net/socket.c:2342 ___sys_sendmsg+0x100/0x170 net/socket.c:2396 __sys_sendmsg+0x105/0x1d0 net/socket.c:2429 __do_sys_sendmsg net/socket.c:2438 [inline] __se_sys_sendmsg net/socket.c:2436 [inline] __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2436 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45af49 Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007ff47b607c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045af49 RDX: 0000000000000000 RSI: 00000000200001c0 RDI: 0000000000000003 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ff47b6086d4 R13: 00000000004c9de9 R14: 00000000004e2e20 R15: 00000000ffffffff