INFO: task syz-executor0:24469 blocked for more than 140 seconds. Not tainted 4.20.0-rc1+ #324 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor0 D19096 24469 5725 0x80000006 Call Trace: context_switch kernel/sched/core.c:2831 [inline] __schedule+0x8cf/0x21d0 kernel/sched/core.c:3472 schedule+0xfe/0x460 kernel/sched/core.c:3516 __rwsem_down_write_failed_common+0xc9a/0x15e0 kernel/locking/rwsem-xadd.c:577 rwsem_down_write_failed+0xe/0x10 kernel/locking/rwsem-xadd.c:606 call_rwsem_down_write_failed+0x17/0x30 arch/x86/lib/rwsem.S:117 __down_write arch/x86/include/asm/rwsem.h:142 [inline] down_write+0xa5/0x130 kernel/locking/rwsem.c:72 deactivate_super+0x2b3/0x320 fs/super.c:359 cleanup_mnt+0xbf/0x160 fs/namespace.c:1098 __cleanup_mnt+0x16/0x20 fs/namespace.c:1105 task_work_run+0x1e8/0x2a0 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x1ad6/0x26d0 kernel/exit.c:867 cgroup: fork rejected by pids controller in /syz3 cgroup: fork rejected by pids controller in /syz4 do_group_exit+0x177/0x440 kernel/exit.c:970 get_signal+0x8b0/0x1980 kernel/signal.c:2517 do_signal+0x9c/0x21c0 arch/x86/kernel/signal.c:816 exit_to_usermode_loop+0x2e5/0x380 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+0x6be/0x820 arch/x86/entry/common.c:293 binder: 30044:30046 ioctl c0306201 20000140 returned -14 cgroup: fork rejected by pids controller in /syz1 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457569 Code: fd b3 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 cb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f5c516b1c78 EFLAGS: 00000246 ORIG_RAX: 000000000000003b RAX: fffffffffffffe00 RBX: 0000000000000003 RCX: 0000000000457569 RDX: 00000000200001c0 RSI: 00000000200002c0 RDI: 0000000020000240 RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f5c516b26d4 R13: 00000000004bdbd4 R14: 00000000004cca58 R15: 00000000ffffffff Showing all locks held in the system: 4 locks held by kworker/u4:0/7: 2 locks held by kworker/0:1/12: #0: 0000000089899012 ((wq_completion)"events"){+.+.}, at: __write_once_size include/linux/compiler.h:209 [inline] #0: 0000000089899012 ((wq_completion)"events"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 0000000089899012 ((wq_completion)"events"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 0000000089899012 ((wq_completion)"events"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 0000000089899012 ((wq_completion)"events"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 0000000089899012 ((wq_completion)"events"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 0000000089899012 ((wq_completion)"events"){+.+.}, at: process_one_work+0xb43/0x1c40 kernel/workqueue.c:2124 #1: 0000000012f9aa5b ((work_completion)(&map->work)){+.+.}, at: process_one_work+0xb9a/0x1c40 kernel/workqueue.c:2128 3 locks held by kworker/u4:3/377: #0: 00000000895d0d5f ((wq_completion)"%s""netns"){+.+.}, at: __write_once_size include/linux/compiler.h:209 [inline] #0: 00000000895d0d5f ((wq_completion)"%s""netns"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 00000000895d0d5f ((wq_completion)"%s""netns"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 00000000895d0d5f ((wq_completion)"%s""netns"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 00000000895d0d5f ((wq_completion)"%s""netns"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 00000000895d0d5f ((wq_completion)"%s""netns"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 00000000895d0d5f ((wq_completion)"%s""netns"){+.+.}, at: process_one_work+0xb43/0x1c40 kernel/workqueue.c:2124 #1: 000000004dbf8bbe (net_cleanup_work){+.+.}, at: process_one_work+0xb9a/0x1c40 kernel/workqueue.c:2128 #2: 00000000b91e4f7b (pernet_ops_rwsem){++++}, at: cleanup_net+0x13f/0xb10 net/core/net_namespace.c:518 1 lock held by khungtaskd/1010: #0: 00000000d96d5385 (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x424 kernel/locking/lockdep.c:4379 1 lock held by rsyslogd/5598: #0: 000000008ebd9ff9 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 2 locks held by getty/5688: #0: 00000000ad671f4f (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000001f7cf9e8 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 binder: 30054:30056 ioctl c0306201 20000140 returned -14 2 locks held by getty/5689: #0: 00000000ac5dfa48 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000009a8e4e35 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5690: #0: 00000000f14000ab (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 0000000089b4fc89 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5691: #0: 00000000d53b23db (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000d150728d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5692: #0: 00000000634a5e6b (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000f6b24a68 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5693: #0: 00000000c92e252d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000ec120523 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5694: #0: 0000000080f2a506 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 0000000094367322 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 3 locks held by kworker/0:2/5832: #0: 0000000089899012 ((wq_completion)"events"){+.+.}, at: __write_once_size include/linux/compiler.h:209 [inline] #0: 0000000089899012 ((wq_completion)"events"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 0000000089899012 ((wq_completion)"events"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 0000000089899012 ((wq_completion)"events"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 0000000089899012 ((wq_completion)"events"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 0000000089899012 ((wq_completion)"events"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 0000000089899012 ((wq_completion)"events"){+.+.}, at: process_one_work+0xb43/0x1c40 kernel/workqueue.c:2124 #1: 00000000251b0930 ((work_completion)(&map->work)){+.+.}, at: process_one_work+0xb9a/0x1c40 kernel/workqueue.c:2128 #2: 0000000055e95526 (rcu_state.barrier_mutex){+.+.}, at: rcu_barrier+0x109/0x4a0 kernel/rcu/tree.c:3077 3 locks held by kworker/0:3/6015: #0: 0000000089899012 ((wq_completion)"events"){+.+.}, at: __write_once_size include/linux/compiler.h:209 [inline] #0: 0000000089899012 ((wq_completion)"events"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 0000000089899012 ((wq_completion)"events"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 0000000089899012 ((wq_completion)"events"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 0000000089899012 ((wq_completion)"events"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 0000000089899012 ((wq_completion)"events"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 0000000089899012 ((wq_completion)"events"){+.+.}, at: process_one_work+0xb43/0x1c40 kernel/workqueue.c:2124 #1: 00000000b5e67978 ((work_completion)(&map->work)){+.+.}, at: process_one_work+0xb9a/0x1c40 kernel/workqueue.c:2128 #2: 0000000055e95526 (rcu_state.barrier_mutex){+.+.}, at: rcu_barrier+0x109/0x4a0 kernel/rcu/tree.c:3077 2 locks held by syz-executor4/9247: #0: 00000000b4c81e9f (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 #1: 0000000074de20a3 (rcu_state.exp_mutex){+.+.}, at: exp_funnel_lock kernel/rcu/tree_exp.h:296 [inline] #1: 0000000074de20a3 (rcu_state.exp_mutex){+.+.}, at: _synchronize_rcu_expedited.constprop.58+0x7c7/0x9d0 kernel/rcu/tree_exp.h:620 2 locks held by kworker/0:4/10030: #0: 0000000018cf89fb ((wq_completion)"rcu_gp"){+.+.}, at: __write_once_size include/linux/compiler.h:209 [inline] #0: 0000000018cf89fb ((wq_completion)"rcu_gp"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 0000000018cf89fb ((wq_completion)"rcu_gp"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 0000000018cf89fb ((wq_completion)"rcu_gp"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 0000000018cf89fb ((wq_completion)"rcu_gp"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 0000000018cf89fb ((wq_completion)"rcu_gp"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 0000000018cf89fb ((wq_completion)"rcu_gp"){+.+.}, at: process_one_work+0xb43/0x1c40 kernel/workqueue.c:2124 #1: 000000007dc55e6e ((work_completion)(&rew.rew_work)){+.+.}, at: process_one_work+0xb9a/0x1c40 kernel/workqueue.c:2128 1 lock held by syz-executor0/24469: #0: 00000000a6c2a170 (&type->s_umount_key#62){++++}, at: deactivate_super+0x2b3/0x320 fs/super.c:359 2 locks held by kworker/0:5/30053: #0: 0000000089899012 ((wq_completion)"events"){+.+.}, at: __write_once_size include/linux/compiler.h:209 [inline] #0: 0000000089899012 ((wq_completion)"events"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 0000000089899012 ((wq_completion)"events"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 0000000089899012 ((wq_completion)"events"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 0000000089899012 ((wq_completion)"events"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 0000000089899012 ((wq_completion)"events"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 0000000089899012 ((wq_completion)"events"){+.+.}, at: process_one_work+0xb43/0x1c40 kernel/workqueue.c:2124 #1: 00000000ecb0e5e6 ((work_completion)(&ns->proc_work)){+.+.}, at: process_one_work+0xb9a/0x1c40 kernel/workqueue.c:2128 2 locks held by kworker/0:6/30055: #0: 0000000089899012 ((wq_completion)"events"){+.+.}, at: __write_once_size include/linux/compiler.h:209 [inline] #0: 0000000089899012 ((wq_completion)"events"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 0000000089899012 ((wq_completion)"events"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 0000000089899012 ((wq_completion)"events"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 0000000089899012 ((wq_completion)"events"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 0000000089899012 ((wq_completion)"events"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 0000000089899012 ((wq_completion)"events"){+.+.}, at: process_one_work+0xb43/0x1c40 kernel/workqueue.c:2124 #1: 0000000089abd3c4 ((work_completion)(&ns->proc_work)){+.+.}, at: process_one_work+0xb9a/0x1c40 kernel/workqueue.c:2128 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1010 Comm: khungtaskd Not tainted 4.20.0-rc1+ #324 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+0x244/0x39d lib/dump_stack.c:113 nmi_cpu_backtrace.cold.2+0x5c/0xa1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1e8/0x22a 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:144 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0xb51/0x1060 kernel/hung_task.c:289 kthread+0x35a/0x440 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 0 to CPUs 1: INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 2.735 msecs NMI backtrace for cpu 1 CPU: 1 PID: 7 Comm: kworker/u4:0 Not tainted 4.20.0-rc1+ #324 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: writeback wb_workfn (flush-7:0) RIP: 0010:match_held_lock+0x2e8/0x8d0 kernel/locking/lockdep.c:3401 Code: 80 4d 89 fc 48 b9 00 00 00 00 00 fc ff df c6 04 08 f8 75 4a 31 c0 48 ba 00 00 00 00 00 fc ff df 48 01 d3 48 c7 03 00 00 00 00 <48> c7 43 08 00 00 00 00 48 8b 75 d0 65 48 33 34 25 28 00 00 00 0f RSP: 0018:ffff8801d9ae5a00 EFLAGS: 00000082 RAX: 0000000000000000 RBX: ffffed003b35cb45 RCX: ffffffff87cb7a6a RDX: dffffc0000000000 RSI: ffff8801c46c6978 RDI: ffff8801d9adaa8a RBP: ffff8801d9ae5af0 R08: ffff8801d9ada1c0 R09: ffffed003b5e5b67 R10: ffffed003b5e5b67 R11: ffff8801daf2db3b R12: ffff8801d9ada1c0 R13: ffff8801d9adaa68 R14: ffff8801d9ae5ac8 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000008217d0 CR3: 00000001b6de0000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __lock_is_held+0xb5/0x140 kernel/locking/lockdep.c:3664 lock_is_held_type+0x118/0x210 kernel/locking/lockdep.c:3882 lock_is_held include/linux/lockdep.h:339 [inline] xa_entry include/linux/xarray.h:709 [inline] xas_descend+0x3ec/0x510 lib/xarray.c:198 xas_load+0x145/0x1e0 lib/xarray.c:234 find_get_entry+0x3ca/0x1120 mm/filemap.c:1415 pagecache_get_page+0x12f/0xf00 mm/filemap.c:1518 find_or_create_page include/linux/pagemap.h:322 [inline] grow_dev_page fs/buffer.c:947 [inline] grow_buffers fs/buffer.c:1016 [inline] __getblk_slow fs/buffer.c:1043 [inline] __getblk_gfp+0x3aa/0xd50 fs/buffer.c:1320 __bread_gfp+0x2d/0x310 fs/buffer.c:1354 sb_bread include/linux/buffer_head.h:307 [inline] __fat_write_inode+0x347/0xb60 fs/fat/inode.c:859 fat_write_inode+0x97/0x180 fs/fat/inode.c:908 write_inode fs/fs-writeback.c:1176 [inline] __writeback_single_inode+0xf56/0x1660 fs/fs-writeback.c:1375 writeback_sb_inodes+0x71f/0x1210 fs/fs-writeback.c:1580 __writeback_inodes_wb+0x1b9/0x340 fs/fs-writeback.c:1649 wb_writeback+0xa73/0xfc0 fs/fs-writeback.c:1758 wb_check_old_data_flush fs/fs-writeback.c:1860 [inline] wb_do_writeback fs/fs-writeback.c:1913 [inline] wb_workfn+0x1008/0x1790 fs/fs-writeback.c:1942 process_one_work+0xc90/0x1c40 kernel/workqueue.c:2153 worker_thread+0x17f/0x1390 kernel/workqueue.c:2296 kthread+0x35a/0x440 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 kobject: 'loop5' (00000000ef9ebffc): kobject_uevent_env