TITLE: INFO: rcu detected stall in sys_sendmmsg
ALT: INFO: rcu detected stall in __x64_sys_sendmmsg
ALT: stall in __x64_sys_sendmmsg
ALT: stall in sys_sendmmsg
TYPE: HANG

[  180.633803][    C1] rcu: INFO: rcu_sched self-detected stall on CPU
[  180.640352][    C1] rcu: 	1-...!: (10499 ticks this GP) idle=72a/1/0x4000000000000000 softirq=10448/10448 fqs=3 
[  180.650842][    C1] 	(t=10500 jiffies g=9717 q=30)
[  180.655770][    C1] rcu: rcu_sched kthread starved for 10494 jiffies! g9717 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
[  180.666678][    C1] rcu: 	Unless rcu_sched kthread gets sufficient CPU time, OOM is now expected behavior.
[  180.676457][    C1] rcu: RCU grace-period kthread stack dump:
[  180.682329][    C1] task:rcu_sched       state:R  running task on cpu   0   stack:    0 pid:   11 ppid:     2 flags:0x00004000
[  180.693859][    C1] Call Trace:
[  180.697138][    C1]  __schedule+0x988/0x26f0
[  180.712182][    C1]  schedule+0xd7/0x280
[  180.716236][    C1]  schedule_timeout+0x15e/0x260
[  180.737153][    C1]  rcu_gp_kthread+0x8e8/0x1790
[  180.780919][    C1]  kthread+0x39a/0x490
[  180.795618][    C1]  ret_from_fork+0x1f/0x30
[  180.800050][    C1] NMI backtrace for cpu 1
[  180.804366][    C1] CPU: 1 PID: 7502 Comm: syz-executor.5 Not tainted 5.10.0-syzkaller #0
[  180.812670][    C1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[  180.822789][    C1] Call Trace:
[  180.826055][    C1]  <IRQ>
[  180.828894][    C1]  dump_stack+0x111/0x171
[  180.838824][    C1]  nmi_cpu_backtrace.cold+0x44/0xd8
[  180.849193][    C1]  nmi_trigger_cpumask_backtrace+0x1e7/0x210
[  180.855160][    C1]  arch_trigger_cpumask_backtrace+0x14/0x20
[  180.861038][    C1]  rcu_dump_cpu_stacks+0x1e8/0x226
[  180.866136][    C1]  rcu_sched_clock_irq.cold+0x48f/0x95b
[  180.871685][    C1]  update_process_times+0x141/0x1c0
[  180.876870][    C1]  tick_sched_handle+0xa2/0x190
[  180.881707][    C1]  tick_sched_timer+0x1d0/0x2a0
[  180.891729][    C1]  __hrtimer_run_queues+0x204/0xec0
[  180.902285][    C1]  hrtimer_interrupt+0x30d/0x900
[  180.907219][    C1]  __sysvec_apic_timer_interrupt+0xfa/0x430
[  180.913094][    C1]  asm_call_irq_on_stack+0xf/0x20
[  180.918094][    C1]  </IRQ>
[  180.921035][    C1]  sysvec_apic_timer_interrupt+0x98/0xb0
[  180.926656][    C1]  asm_sysvec_apic_timer_interrupt+0x12/0x20
[  180.932623][    C1] RIP: 0010:lock_is_held_type+0xb0/0xe0
[  180.938158][    C1] Code: ff 74 11 41 0f b6 47 22 45 31 c0 83 e0 03 39 d0 41 0f 94 c0 b8 ff ff ff ff 65 0f c1 05 59 93 8e 7b 83 f8 01 75 23 ff 75 d0 9d <48> 83 c4 10 44 89 c0 5b 41 5c 41 5d 41 5e 41 5f 5d c3 45 31 c0 eb
[  180.957769][    C1] RSP: 0018:ffff88811570f3d0 EFLAGS: 00000202
[  180.963821][    C1] RAX: 0000000000000001 RBX: ffffffff86187aa0 RCX: 1ffffffff0d765f3
[  180.971777][    C1] RDX: 0000000000000000 RSI: ffffffff86187aa0 RDI: ffff8881118f8cb0
[  180.979731][    C1] RBP: ffff88811570f408 R08: 0000000000000000 R09: ffffffff86bb000f
[  180.987690][    C1] R10: fffffbfff0d76001 R11: 0000000000000000 R12: ffff8881118f8300
[  180.995646][    C1] R13: ffff8881118f8cb0 R14: 0000000000000001 R15: ffff8881118f8cb0
[  181.003632][    C1]  rcu_read_lock_sched_held+0x41/0x80
[  181.009007][    C1]  lock_acquire+0x5c1/0x770
[  181.032369][    C1]  _raw_spin_lock+0x2b/0x40
[  181.042299][    C1]  __migration_entry_wait+0x24/0x3f0
[  181.047574][    C1]  migration_entry_wait+0x114/0x190
[  181.052763][    C1]  do_swap_page+0x1616/0x23b0
[  181.062451][    C1]  handle_mm_fault+0x1eef/0x4140
[  181.076886][    C1]  do_user_addr_fault+0x49f/0xa00
[  181.081899][    C1]  exc_page_fault+0xa3/0x180
[  181.086472][    C1]  asm_exc_page_fault+0x1e/0x30
[  181.091307][    C1] RIP: 0010:copy_user_generic_unrolled+0x86/0xc0
[  181.097620][    C1] Code: 4c 8b 5e 38 4c 89 47 20 4c 89 4f 28 4c 89 57 30 4c 89 5f 38 48 8d 76 40 48 8d 7f 40 ff c9 75 b6 89 d1 83 e2 07 c1 e9 03 74 12 <4c> 8b 06 4c 89 07 48 8d 76 08 48 8d 7f 08 ff c9 75 ee 21 d2 74 10
[  181.117215][    C1] RSP: 0018:ffff88811570f8f0 EFLAGS: 00050202
[  181.123268][    C1] RAX: 0000000000000001 RBX: 0000000020003300 RCX: 0000000000000007
[  181.131223][    C1] RDX: 0000000000000000 RSI: 0000000020003300 RDI: ffff88811570f968
[  181.139175][    C1] RBP: ffff88811570f920 R08: 0000000000000001 R09: ffff88811570f99f
[  181.147128][    C1] R10: ffffed1022ae1f33 R11: 0000000000000000 R12: 0000000000000038
[  181.155083][    C1] R13: 0000000020003338 R14: ffff88811570f968 R15: 0000000000000000
[  181.167899][    C1]  __copy_msghdr_from_user+0xa7/0x4e0
[  181.178367][    C1]  sendmsg_copy_msghdr+0xb1/0x170
[  181.197885][    C1]  ___sys_sendmsg+0xe8/0x190
[  181.243058][    C1]  __sys_sendmmsg+0x1bf/0x4d0
[  181.280044][    C1]  __x64_sys_sendmmsg+0x9d/0x100
[  181.290858][    C1]  do_syscall_64+0x32/0x50
[  181.295261][    C1]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[  181.301135][    C1] RIP: 0033:0x4665f9
[  181.305026][    C1] Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
[  181.324613][    C1] RSP: 002b:00007ff913845188 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
[  181.333009][    C1] RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 00000000004665f9
[  181.340963][    C1] RDX: 00000000000001a3 RSI: 0000000020002cc0 RDI: 0000000000000004
[  181.348916][    C1] RBP: 00000000004c0881 R08: 0000000000000000 R09: 0000000000000000
[  181.356871][    C1] R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60
[  181.364825][    C1] R13: 00007ffea137e1ff R14: 00007ff913845300 R15: 0000000000022000
