INFO: task syz-executor3:25330 blocked for more than 140 seconds. Not tainted 4.20.0-rc2+ #115 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor3 D21264 25330 24176 0x00000004 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 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3574 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0xaff/0x16f0 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 pipe_lock_nested fs/pipe.c:62 [inline] pipe_lock fs/pipe.c:70 [inline] pipe_wait+0x266/0x2c0 fs/pipe.c:118 pipe_read+0x37c/0x940 fs/pipe.c:333 call_read_iter include/linux/fs.h:1851 [inline] new_sync_read fs/read_write.c:406 [inline] __vfs_read+0x6ac/0x9b0 fs/read_write.c:418 vfs_read+0x17f/0x3c0 fs/read_write.c:452 ksys_read+0x101/0x260 fs/read_write.c:578 __do_sys_read fs/read_write.c:588 [inline] __se_sys_read fs/read_write.c:586 [inline] __x64_sys_read+0x73/0xb0 fs/read_write.c:586 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 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:00007f9187f4fc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457569 RDX: 00000000fffffe64 RSI: 0000000020000200 RDI: 0000000000000004 RBP: 000000000072bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f9187f506d4 R13: 00000000004c286a R14: 00000000004d5340 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/1021: #0: 00000000509bd1f7 (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x424 kernel/locking/lockdep.c:4379 1 lock held by kswapd0/1522: 3 locks held by rs:main Q:Reg/5913: #0: 0000000002190bd0 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 #1: 00000000abe6f91b (sb_writers#3){.+.+}, at: file_start_write include/linux/fs.h:2810 [inline] #1: 00000000abe6f91b (sb_writers#3){.+.+}, at: vfs_write+0x42a/0x560 fs/read_write.c:548 #2: 000000005eec2d79 (&sb->s_type->i_mutex_key#9){++++}, at: inode_lock include/linux/fs.h:757 [inline] #2: 000000005eec2d79 (&sb->s_type->i_mutex_key#9){++++}, at: __generic_file_fsync+0xb5/0x200 fs/libfs.c:981 1 lock held by rsyslogd/5916: #0: 0000000027c9deaa (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 2 locks held by getty/6005: #0: 000000002f6cc737 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000a7e3ac76 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/6006: #0: 00000000fafc5d4d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 0000000054573438 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/6007: #0: 00000000e98d7126 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 0000000095fc0fc2 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/6008: #0: 000000007748f698 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000e3ff5c5e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/6009: #0: 00000000b2bd0514 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000208f9160 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/6010: #0: 0000000097072e88 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 0000000075812583 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/6011: #0: 00000000bf2fe115 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000ea35a968 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 4 locks held by syz-executor3/25323: 1 lock held by syz-executor3/25330: #0: 0000000093390dd7 (&pipe->mutex/1){+.+.}, at: pipe_lock_nested fs/pipe.c:62 [inline] #0: 0000000093390dd7 (&pipe->mutex/1){+.+.}, at: pipe_lock fs/pipe.c:70 [inline] #0: 0000000093390dd7 (&pipe->mutex/1){+.+.}, at: pipe_wait+0x266/0x2c0 fs/pipe.c:118 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1021 Comm: khungtaskd Not tainted 4.20.0-rc2+ #115 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:146 [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 1 to CPUs 0: INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 2.493 msecs NMI backtrace for cpu 0 CPU: 0 PID: 1522 Comm: kswapd0 Not tainted 4.20.0-rc2+ #115 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:debug_spin_unlock kernel/locking/spinlock_debug.c:99 [inline] RIP: 0010:do_raw_spin_unlock+0x12a/0x330 kernel/locking/spinlock_debug.c:134 Code: 45 89 77 c0 48 b8 00 00 00 00 00 fc ff df 41 c6 04 04 f8 0f 84 86 01 00 00 4c 8d 73 10 48 b8 00 00 00 00 00 fc ff df 4c 89 f2 <48> c1 ea 03 80 3c 02 00 0f 85 c6 01 00 00 65 48 8b 04 25 40 ee 01 RSP: 0018:ffff8881d4234aa0 EFLAGS: 00000002 RAX: dffffc0000000000 RBX: ffffffff8b225ea8 RCX: ffffffff8162e8c7 RDX: ffffffff8b225eb8 RSI: 0000000000000004 RDI: ffffffff8b225ea8 RBP: ffff8881d4234b28 R08: fffffbfff1644bd6 R09: fffffbfff1644bd5 R10: fffffbfff1644bd5 R11: ffffffff8b225eab R12: 1ffff1103a846958 R13: 1ffff1103a846954 R14: ffffffff8b225eb8 R15: ffff8881d4234b00 FS: 0000000000000000(0000) GS:ffff8881dae00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000422d10 CR3: 000000018784f000 CR4: 00000000001406f0 Call Trace: __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:159 [inline] _raw_spin_unlock_irqrestore+0x27/0xd0 kernel/locking/spinlock.c:184 __debug_check_no_obj_freed lib/debugobjects.c:799 [inline] debug_check_no_obj_freed+0x305/0x58d lib/debugobjects.c:818 free_pages_prepare mm/page_alloc.c:1034 [inline] free_pcp_prepare mm/page_alloc.c:1048 [inline] free_unref_page_prepare mm/page_alloc.c:2743 [inline] free_unref_page_list+0x3c4/0x11e0 mm/page_alloc.c:2812 shrink_page_list+0x6dc3/0xccd0 mm/vmscan.c:1501 shrink_inactive_list+0x77b/0x1c60 mm/vmscan.c:1963 shrink_list mm/vmscan.c:2275 [inline] shrink_node_memcg+0x78b/0x18f0 mm/vmscan.c:2540 shrink_node+0x3bc/0x16b0 mm/vmscan.c:2755 kswapd_shrink_node mm/vmscan.c:3485 [inline] balance_pgdat+0x7ee/0x1050 mm/vmscan.c:3597 ? __alloc_pages Lost 22 message(s)!