INFO: task syz-executor.3:17213 blocked for more than 178 seconds. Not tainted 5.1.0-rc2 #36 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D27032 17213 7864 0x80000006 Call Trace: context_switch kernel/sched/core.c:2877 [inline] __schedule+0x817/0x1cc0 kernel/sched/core.c:3518 do_task_dead+0xc7/0x100 kernel/sched/core.c:3535 do_exit+0x1ff2/0x2fa0 kernel/exit.c:934 do_group_exit+0x135/0x370 kernel/exit.c:980 get_signal+0x399/0x1d50 kernel/signal.c:2577 do_signal+0x87/0x1940 arch/x86/kernel/signal.c:816 exit_to_usermode_loop+0x244/0x2c0 arch/x86/entry/common.c:162 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] syscall_return_slowpath arch/x86/entry/common.c:268 [inline] do_syscall_64+0x52d/0x610 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x458077 Code: 20 44 0f b6 4a 28 48 8b 52 30 c6 81 c9 02 00 00 01 48 8b 4b 10 4c 8b 53 08 48 8b 1b 49 39 ca 0f 87 23 01 00 00 48 89 74 24 38 <48> 89 7c 24 30 4c 89 44 24 28 44 88 4c 24 27 48 89 54 24 50 48 89 RSP: 002b:00007fec27557a88 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: 0000000000000000 RBX: 0000000020000068 RCX: 0000000000458077 RDX: 0000000000000005 RSI: 0000000000004c00 RDI: 0000000000000006 RBP: 0000000000000001 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000246 R12: 0000000000000005 R13: 00000000004c6b6b R14: 00000000004dc178 R15: 00000000ffffffff Showing all locks held in the system: 3 locks held by ksoftirqd/1/16: 1 lock held by khungtaskd/1042: #0: 0000000029561616 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:5061 1 lock held by rsyslogd/7709: #0: 000000008ad61c3f (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801 2 locks held by getty/7821: #0: 000000005c678f68 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000077ae10a4 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7822: #0: 000000006bd3ca16 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000016c67618 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7823: #0: 000000007a91ee4b (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000b617f9d9 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7824: #0: 0000000030a1a1db (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000cbe01f00 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7825: #0: 00000000da62bc7c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000224d499b (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7826: #0: 00000000d3d2be9d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000099df3e07 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7827: #0: 000000006f5a1171 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000050bd4f1b (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 1 lock held by syz-executor.2/8062: #0: 000000006969c9f0 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:76 3 locks held by kworker/0:0/31131: #0: 00000000d6fec4f4 ((wq_completion)ipv6_addrconf){+.+.}, at: __write_once_size include/linux/compiler.h:220 [inline] #0: 00000000d6fec4f4 ((wq_completion)ipv6_addrconf){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 00000000d6fec4f4 ((wq_completion)ipv6_addrconf){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: 00000000d6fec4f4 ((wq_completion)ipv6_addrconf){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: 00000000d6fec4f4 ((wq_completion)ipv6_addrconf){+.+.}, at: set_work_data kernel/workqueue.c:619 [inline] #0: 00000000d6fec4f4 ((wq_completion)ipv6_addrconf){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline] #0: 00000000d6fec4f4 ((wq_completion)ipv6_addrconf){+.+.}, at: process_one_work+0x87e/0x1790 kernel/workqueue.c:2240 #1: 00000000f1ef99c1 ((addr_chk_work).work){+.+.}, at: process_one_work+0x8b4/0x1790 kernel/workqueue.c:2244 #2: 000000006969c9f0 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:76 1 lock held by syz-executor.3/2579: #0: 000000006969c9f0 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:76 2 locks held by syz-executor.5/2681: #0: 000000006969c9f0 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:76 #1: 00000000f8351093 (rcu_state.exp_mutex){+.+.}, at: exp_funnel_lock kernel/rcu/tree_exp.h:285 [inline] #1: 00000000f8351093 (rcu_state.exp_mutex){+.+.}, at: synchronize_rcu_expedited+0x4ab/0x5b0 kernel/rcu/tree_exp.h:758 1 lock held by syz-executor.0/17216: #0: 000000006969c9f0 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:76 1 lock held by syz-executor.1/17218: #0: 000000006969c9f0 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:76 2 locks held by blkid/17225: #0: 000000007a31305c (&bdev->bd_mutex){+.+.}, at: __blkdev_put+0xbb/0x810 fs/block_dev.c:1833 #1: 000000002471736f (loop_ctl_mutex){+.+.}, at: lo_release+0x1f/0x200 drivers/block/loop.c:1755 2 locks held by kworker/1:9/17334: #0: 0000000076913e57 ((wq_completion)rcu_gp){+.+.}, at: __write_once_size include/linux/compiler.h:220 [inline] #0: 0000000076913e57 ((wq_completion)rcu_gp){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 0000000076913e57 ((wq_completion)rcu_gp){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: 0000000076913e57 ((wq_completion)rcu_gp){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: 0000000076913e57 ((wq_completion)rcu_gp){+.+.}, at: set_work_data kernel/workqueue.c:619 [inline] #0: 0000000076913e57 ((wq_completion)rcu_gp){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline] #0: 0000000076913e57 ((wq_completion)rcu_gp){+.+.}, at: process_one_work+0x87e/0x1790 kernel/workqueue.c:2240 #1: 00000000e6811189 ((work_completion)(&rew.rew_work)){+.+.}, at: process_one_work+0x8b4/0x1790 kernel/workqueue.c:2244 3 locks held by kworker/1:10/17335: #0: 0000000070e06e96 ((wq_completion)events){+.+.}, at: __write_once_size include/linux/compiler.h:220 [inline] #0: 0000000070e06e96 ((wq_completion)events){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 0000000070e06e96 ((wq_completion)events){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: 0000000070e06e96 ((wq_completion)events){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: 0000000070e06e96 ((wq_completion)events){+.+.}, at: set_work_data kernel/workqueue.c:619 [inline] #0: 0000000070e06e96 ((wq_completion)events){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline] #0: 0000000070e06e96 ((wq_completion)events){+.+.}, at: process_one_work+0x87e/0x1790 kernel/workqueue.c:2240 #1: 0000000077cbb3e7 ((linkwatch_work).work){+.+.}, at: process_one_work+0x8b4/0x1790 kernel/workqueue.c:2244 #2: 000000006969c9f0 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:76 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1042 Comm: khungtaskd Not tainted 5.1.0-rc2 #36 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+0x172/0x1f0 lib/dump_stack.c:113 nmi_cpu_backtrace.cold+0x63/0xa4 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1be/0x236 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:204 [inline] watchdog+0x9b7/0xec0 kernel/hung_task.c:288 kthread+0x357/0x430 kernel/kthread.c:253 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 0 to CPUs 1: