INFO: task syz-executor.2:10719 blocked for more than 143 seconds. Not tainted 5.2.0+ #61 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D23944 10719 1 0x80004006 Call Trace: context_switch /kernel/sched/core.c:3254 [inline] __schedule+0x755/0x1580 /kernel/sched/core.c:3880 schedule+0xa8/0x270 /kernel/sched/core.c:3944 schedule_preempt_disabled+0x13/0x20 /kernel/sched/core.c:4003 __mutex_lock_common /kernel/locking/mutex.c:1003 [inline] __mutex_lock+0x751/0x1340 /kernel/locking/mutex.c:1073 mutex_lock_nested+0x16/0x20 /kernel/locking/mutex.c:1088 exp_funnel_lock /kernel/rcu/tree_exp.h:317 [inline] synchronize_rcu_expedited+0x26f/0x5b0 /kernel/rcu/tree_exp.h:816 namespace_unlock+0x108/0x130 /fs/namespace.c:1385 drop_collected_mounts+0x82/0x90 /fs/namespace.c:1863 put_mnt_ns /fs/namespace.c:3757 [inline] put_mnt_ns+0x6a/0x90 /fs/namespace.c:3753 free_nsproxy+0x48/0x230 /kernel/nsproxy.c:172 switch_task_namespaces+0xb3/0xd0 /kernel/nsproxy.c:225 exit_task_namespaces+0x18/0x20 /kernel/nsproxy.c:230 do_exit+0x92a/0x2ea0 /kernel/exit.c:876 do_group_exit+0x135/0x360 /kernel/exit.c:981 get_signal+0x47c/0x2500 /kernel/signal.c:2728 do_signal+0x87/0x1670 /arch/x86/kernel/signal.c:815 exit_to_usermode_loop+0x286/0x380 /arch/x86/entry/common.c:159 prepare_exit_to_usermode /arch/x86/entry/common.c:194 [inline] syscall_return_slowpath /arch/x86/entry/common.c:274 [inline] do_syscall_64+0x5a9/0x6a0 /arch/x86/entry/common.c:299 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4137aa Code: 06 00 00 00 00 bf 58 30 44 00 b9 08 00 00 00 48 89 ee f3 a6 74 2a bf 60 30 44 00 b9 09 00 00 00 48 89 ee f3 a6 75 29 48 c7 03 <50> 37 41 00 31 c0 48 83 c4 08 5b 5d c3 66 0f 1f 84 00 00 00 00 00 RSP: 002b:00007ffc8e4cc398 EFLAGS: 00000246 ORIG_RAX: 000000000000003d RAX: fffffffffffffe00 RBX: 0000555556037940 RCX: 00000000004137aa RDX: 0000000040000000 RSI: 00007ffc8e4cc3d0 RDI: ffffffffffffffff RBP: 000000000000164d R08: 0000000000000001 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000007 R13: 00007ffc8e4cc3d0 R14: 000055555603799b R15: 00007ffc8e4cc3e0 INFO: task kworker/0:1:15212 blocked for more than 143 seconds. Not tainted 5.2.0+ #61 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/0:1 D26392 15212 2 0x80004000 Workqueue: ipv6_addrconf addrconf_verify_work Call Trace: context_switch /kernel/sched/core.c:3254 [inline] __schedule+0x755/0x1580 /kernel/sched/core.c:3880 schedule+0xa8/0x270 /kernel/sched/core.c:3944 schedule_preempt_disabled+0x13/0x20 /kernel/sched/core.c:4003 __mutex_lock_common /kernel/locking/mutex.c:1003 [inline] __mutex_lock+0x751/0x1340 /kernel/locking/mutex.c:1073 mutex_lock_nested+0x16/0x20 /kernel/locking/mutex.c:1088 rtnl_lock+0x17/0x20 /net/core/rtnetlink.c:72 addrconf_verify_work+0xe/0x20 /net/ipv6/addrconf.c:4519 process_one_work+0x9af/0x1740 /kernel/workqueue.c:2269 worker_thread+0x98/0xe40 /kernel/workqueue.c:2415 kthread+0x361/0x430 /kernel/kthread.c:255 ret_from_fork+0x24/0x30 /arch/x86/entry/entry_64.S:352 Showing all locks held in the system: 1 lock held by khungtaskd/1050: #0: 0000000060404c83 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e /kernel/locking/lockdep.c:5257 2 locks held by rs:main Q:Reg/10547: 1 lock held by rsyslogd/10549: #0: 00000000e1de0119 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 /fs/file.c:801 2 locks held by getty/10671: #0: 00000000da591497 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 /drivers/tty/tty_ldsem.c:341 #1: 000000002a21c7b8 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 /drivers/tty/n_tty.c:2156 2 locks held by getty/10672: #0: 000000009f05d740 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 /drivers/tty/tty_ldsem.c:341 #1: 000000003c158558 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 /drivers/tty/n_tty.c:2156 2 locks held by getty/10673: #0: 00000000bae93e6c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 /drivers/tty/tty_ldsem.c:341 #1: 0000000092f99f08 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 /drivers/tty/n_tty.c:2156 2 locks held by getty/10674: #0: 00000000cf100ab4 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 /drivers/tty/tty_ldsem.c:341 #1: 00000000aecd3b28 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 /drivers/tty/n_tty.c:2156 2 locks held by getty/10675: #0: 000000008488e4f0 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 /drivers/tty/tty_ldsem.c:341 #1: 00000000da3c5374 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 /drivers/tty/n_tty.c:2156 2 locks held by getty/10676: #0: 00000000c26c50e9 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 /drivers/tty/tty_ldsem.c:341 #1: 000000006ac480da (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 /drivers/tty/n_tty.c:2156 2 locks held by getty/10677: #0: 000000005a1479b6 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 /drivers/tty/tty_ldsem.c:341 #1: 000000009c091b69 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 /drivers/tty/n_tty.c:2156 1 lock held by syz-executor.2/10719: #0: 00000000e1eb0f8a (rcu_state.exp_mutex){+.+.}, at: exp_funnel_lock /kernel/rcu/tree_exp.h:317 [inline] #0: 00000000e1eb0f8a (rcu_state.exp_mutex){+.+.}, at: synchronize_rcu_expedited+0x26f/0x5b0 /kernel/rcu/tree_exp.h:816 3 locks held by kworker/0:1/15212: #0: 000000005aec598f ((wq_completion)ipv6_addrconf){+.+.}, at: __write_once_size /./include/linux/compiler.h:221 [inline] #0: 000000005aec598f ((wq_completion)ipv6_addrconf){+.+.}, at: arch_atomic64_set /./arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 000000005aec598f ((wq_completion)ipv6_addrconf){+.+.}, at: atomic64_set /./include/asm-generic/atomic-instrumented.h:855 [inline] #0: 000000005aec598f ((wq_completion)ipv6_addrconf){+.+.}, at: atomic_long_set /./include/asm-generic/atomic-long.h:40 [inline] #0: 000000005aec598f ((wq_completion)ipv6_addrconf){+.+.}, at: set_work_data /kernel/workqueue.c:620 [inline] #0: 000000005aec598f ((wq_completion)ipv6_addrconf){+.+.}, at: set_work_pool_and_clear_pending /kernel/workqueue.c:647 [inline] #0: 000000005aec598f ((wq_completion)ipv6_addrconf){+.+.}, at: process_one_work+0x88b/0x1740 /kernel/workqueue.c:2240 #1: 00000000b5dbbf5e ((addr_chk_work).work){+.+.}, at: process_one_work+0x8c1/0x1740 /kernel/workqueue.c:2244 #2: 00000000bb01d85a (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 /net/core/rtnetlink.c:72 2 locks held by syz-executor.2/749: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1050 Comm: khungtaskd Not tainted 5.2.0+ #61 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+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:205 [inline] watchdog+0x9d0/0xef0 /kernel/hung_task.c:289 kthread+0x361/0x430 /kernel/kthread.c:255 ret_from_fork+0x24/0x30 /arch/x86/entry/entry_64.S:352 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 21 Comm: kworker/u4:1 Not tainted 5.2.0+ #61 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker RIP: 0010:__rcu_read_unlock+0xea/0x130 /kernel/rcu/tree_plugin.h:403 Code: c0 75 5e 48 b8 00 00 00 00 00 fc ff df 4c 89 e2 48 c1 ea 03 0f b6 04 02 84 c0 74 04 3c 03 7e 37 c7 83 78 03 00 00 00 00 00 00 <5b> 41 5c 5d c3 0f 0b 5b 41 5c 5d c3 4c 89 e7 e8 42 54 4c 00 e9 35 RSP: 0018:ffff8880a9a57cc0 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffff8880a9a46580 RCX: ffffffff871b82f1 RDX: 1ffff11015348d1f RSI: ffffffff871b805f RDI: ffff8880a9a468fc RBP: ffff8880a9a57cd0 R08: ffff8880a9a46580 R09: ffffed1015d26c84 R10: ffffed1015d26c83 R11: ffff8880ae93641b R12: ffff8880a9a468f8 R13: 000000000000000c R14: 0000000000000001 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffff600400 CR3: 00000000895b3000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_read_unlock /./include/linux/rcupdate.h:645 [inline] batadv_nc_purge_orig_hash /net/batman-adv/network-coding.c:411 [inline] batadv_nc_worker+0x208/0x760 /net/batman-adv/network-coding.c:718 process_one_work+0x9af/0x1740 /kernel/workqueue.c:2269 worker_thread+0x98/0xe40 /kernel/workqueue.c:2415 kthread+0x361/0x430 /kernel/kthread.c:255 ret_from_fork+0x24/0x30 /arch/x86/entry/entry_64.S:352