sctp: sctp_transport_update_pmtu: Reported pmtu 72 too low, using default minimum of 512 xprt_adjust_timeout: rq_timeout = 0! sctp: sctp_transport_update_pmtu: Reported pmtu 72 too low, using default minimum of 512 INFO: task syz-executor0:15411 blocked for more than 140 seconds. Not tainted 4.20.0-rc5+ #364 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor0 D20680 15411 1 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 __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 inode_lock include/linux/fs.h:757 [inline] vfs_unlink+0xd1/0x510 fs/namei.c:3991 do_unlinkat+0x6cc/0xa30 fs/namei.c:4063 __do_sys_unlink fs/namei.c:4110 [inline] __se_sys_unlink fs/namei.c:4108 [inline] __x64_sys_unlink+0x42/0x50 fs/namei.c:4108 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4572b7 Code: Bad RIP value. RSP: 002b:0000000000a3dbb8 EFLAGS: 00000246 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004572b7 RDX: 0000000000a3dbd0 RSI: 0000000000a3dbd0 RDI: 0000000000a3dc60 RBP: 0000000000000136 R08: 0000000000000000 R09: 0000000000000011 R10: 0000000000000005 R11: 0000000000000246 R12: 0000000000a3ed50 R13: 000000000241f980 R14: 0000000000000000 R15: 0000000000000000 Showing all locks held in the system: 1 lock held by khungtaskd/1019: #0: 0000000023004da3 (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x424 kernel/locking/lockdep.c:4379 1 lock held by rsyslogd/5939: #0: 0000000000c1d834 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 2 locks held by getty/6030: #0: 00000000e3af5803 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 0000000027e61833 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/6031: #0: 00000000aef32d72 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 0000000026fb6505 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/6032: #0: 00000000a15c9cad (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000436916b6 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/6033: #0: 000000000196e60f (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000412d8cb7 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/6035: #0: 000000002651a70c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000bc48b6d1 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/6036: #0: 00000000cfda2e56 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 0000000051c113be (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/6037: #0: 00000000179bee31 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000002fa012a3 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 3 locks held by syz-executor0/15411: #0: 000000007f055bc9 (sb_writers#5){.+.+}, at: sb_start_write include/linux/fs.h:1597 [inline] #0: 000000007f055bc9 (sb_writers#5){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:360 #1: 00000000a7df2d62 (&type->i_mutex_dir_key#4/1){+.+.}, at: inode_lock_nested include/linux/fs.h:792 [inline] #1: 00000000a7df2d62 (&type->i_mutex_dir_key#4/1){+.+.}, at: do_unlinkat+0x3d8/0xa30 fs/namei.c:4049 #2: 00000000bcdc830e (&sb->s_type->i_mutex_key#12){+.+.}, at: inode_lock include/linux/fs.h:757 [inline] #2: 00000000bcdc830e (&sb->s_type->i_mutex_key#12){+.+.}, at: vfs_unlink+0xd1/0x510 fs/namei.c:3991 3 locks held by syz-executor0/15965: #0: 00000000e82d2fae (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 #1: 000000007f055bc9 (sb_writers#5){.+.+}, at: file_start_write include/linux/fs.h:2810 [inline] #1: 000000007f055bc9 (sb_writers#5){.+.+}, at: vfs_write+0x42a/0x560 fs/read_write.c:548 #2: 00000000bcdc830e (&sb->s_type->i_mutex_key#12){+.+.}, at: inode_lock include/linux/fs.h:757 [inline] #2: 00000000bcdc830e (&sb->s_type->i_mutex_key#12){+.+.}, at: generic_file_write_iter+0xe4/0x6b0 mm/filemap.c:3290 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1019 Comm: khungtaskd Not tainted 4.20.0-rc5+ #364 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: 2.175 msecs NMI backtrace for cpu 0 CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.20.0-rc5+ #364 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:update_sg_lb_stats kernel/sched/fair.c:7914 [inline] RIP: 0010:update_sd_lb_stats+0x416/0x3230 kernel/sched/fair.c:8118 Code: 8b 85 a8 fc ff ff 48 c1 e8 03 42 80 3c 38 00 0f 85 c7 17 00 00 48 8b 85 28 fd ff ff 44 89 c7 48 8b b5 f0 fc ff ff 48 8b 50 38 45 0e 78 06 41 89 c0 48 c7 c0 d4 3e 16 8a 48 c1 e8 03 42 0f b6 RSP: 0018:ffff8881dae06c08 EFLAGS: 00000246 RAX: ffff8881dae07348 RBX: ffff8881dae070a8 RCX: 0000000000000000 RDX: ffff8881dae1f610 RSI: ffff8881d9a628a0 RDI: 0000000000000000 RBP: ffff8881dae06fb0 R08: 0000000000000000 R09: ffffffff89273020 R10: 0000000000000003 R11: 0000000000000000 R12: ffff8881dae2cc80 R13: ffff8881dae07020 R14: ffff8881d9a61800 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8881dae00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffff600400 CR3: 00000001b47f2000 CR4: 00000000001426f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: find_busiest_group+0xf9/0x2060 kernel/sched/fair.c:8396 load_balance+0x687/0x39a0 kernel/sched/fair.c:8693 rebalance_domains+0x845/0xdc0 kernel/sched/fair.c:9109 _nohz_idle_balance+0x621/0x7a0 kernel/sched/fair.c:9495 nohz_idle_balance kernel/sched/fair.c:9543 [inline] run_rebalance_domains+0x2ec/0x500 kernel/sched/fair.c:9726 __do_softirq+0x308/0xb7e kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x17f/0x1c0 kernel/softirq.c:413 scheduler_ipi+0x55a/0xad0 kernel/sched/core.c:1785 smp_reschedule_interrupt+0x109/0x650 arch/x86/kernel/smp.c:278 reschedule_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:828 RIP: 0010:native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:57 Code: e9 2c ff ff ff 48 89 c7 48 89 45 d8 e8 23 40 e7 f9 48 8b 45 d8 e9 ca fe ff ff 48 89 df e8 12 40 e7 f9 eb 82 55 48 89 e5 fb f4 <5d> c3 0f 1f 84 00 00 00 00 00 55 48 89 e5 f4 5d c3 90 90 90 90 90 RSP: 0018:ffffffff89407c10 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff02 RAX: dffffc0000000000 RBX: 1ffffffff1280f86 RCX: 0000000000000000 RDX: 1ffffffff12a4021 RSI: 0000000000000001 RDI: ffffffff89520108 RBP: ffffffff89407c10 R08: ffffffff89476ec0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff89407cd0 R13: ffffffff8a163ce0 R14: 0000000000000000 R15: 0000000000000000 arch_safe_halt arch/x86/include/asm/paravirt.h:151 [inline] default_idle+0xbf/0x490 arch/x86/kernel/process.c:561 arch_cpu_idle+0x10/0x20 arch/x86/kernel/process.c:552 default_idle_call+0x6d/0x90 kernel/sched/idle.c:93 cpuidle_idle_call kernel/sched/idle.c:153 [inline] do_idle+0x49b/0x5c0 kernel/sched/idle.c:262 cpu_startup_entry+0x18/0x20 kernel/sched/idle.c:353 rest_init+0x243/0x372 init/main.c:443 arch_call_rest_init+0xe/0x1b start_kernel+0x9f5/0xa30 init/main.c:745 x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:470 x86_64_start_kernel+0x76/0x79 arch/x86/kernel/head64.c:451 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243