rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (10499 ticks this GP) idle=599/1/0x4000000000000000 softirq=11508/11508 fqs=3 (t=10501 jiffies g=13801 q=82) rcu: rcu_preempt kthread starved for 10496 jiffies! g13801 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. rcu: RCU grace-period kthread stack dump: task:rcu_preempt state:R running task stack:28696 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4955 [inline] __schedule+0x940/0x26f0 kernel/sched/core.c:6236 schedule+0xd3/0x270 kernel/sched/core.c:6315 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881 rcu_gp_fqs_loop+0x186/0x810 kernel/rcu/tree.c:1955 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2128 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 8740 Comm: syz-executor.4 Not tainted 5.15.0-rc2-next-20210922-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:native_irq_disable arch/x86/include/asm/irqflags.h:40 [inline] RIP: 0010:arch_local_irq_disable arch/x86/include/asm/irqflags.h:75 [inline] RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:107 [inline] RIP: 0010:lock_is_held_type+0x54/0x140 kernel/locking/lockdep.c:5664 Code: c0 0f 85 ca 00 00 00 65 4c 8b 24 25 40 70 02 00 41 8b 94 24 64 0a 00 00 85 d2 0f 85 b1 00 00 00 48 89 fd 41 89 f6 9c 8f 04 24 48 c7 c7 60 01 8c 89 31 db e8 fd 0d 00 00 41 8b 84 24 60 0a 00 RSP: 0018:ffffc90017b975c8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 1ffff92002f72ec5 RCX: 0000000000000001 RDX: 0000000000000000 RSI: 00000000ffffffff RDI: ffffffff8b980920 RBP: ffffffff8b980920 R08: 0000000000000000 R09: ffff8880b9c3aa0b R10: ffffed1017387541 R11: 0000000000000000 R12: ffff888026155700 R13: 00000000ffffffff R14: 00000000ffffffff R15: 0000000000000000 FS: 00007f548d1ae700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2e030000 CR3: 0000000079e39000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_is_held include/linux/lockdep.h:283 [inline] rcu_read_lock_sched_held+0x3a/0x70 kernel/rcu/update.c:125 trace_lock_acquire include/trace/events/lock.h:13 [inline] lock_acquire+0x442/0x510 kernel/locking/lockdep.c:5596 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline] _raw_spin_lock_bh+0x2f/0x40 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:373 [inline] release_sock+0x1b/0x1b0 net/core/sock.c:3196 mptcp_wait_data net/mptcp/protocol.c:1770 [inline] mptcp_recvmsg+0xfd1/0x27b0 net/mptcp/protocol.c:2080 inet6_recvmsg+0x11b/0x5e0 net/ipv6/af_inet6.c:659 sock_recvmsg_nosec net/socket.c:944 [inline] ____sys_recvmsg+0x527/0x600 net/socket.c:2626 ___sys_recvmsg+0x127/0x200 net/socket.c:2670 do_recvmmsg+0x24d/0x6d0 net/socket.c:2764 __sys_recvmmsg net/socket.c:2843 [inline] __do_sys_recvmmsg net/socket.c:2866 [inline] __se_sys_recvmmsg net/socket.c:2859 [inline] __x64_sys_recvmmsg+0x20b/0x260 net/socket.c:2859 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f548fc79709 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 RSP: 002b:00007f548d1ae188 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00007f548fd7e0e0 RCX: 00007f548fc79709 RDX: 0000000000000002 RSI: 00000000200017c0 RDI: 0000000000000004 RBP: 00007f548fcd3cb4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000100 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffea5e061ef R14: 00007f548d1ae300 R15: 0000000000022000 NMI backtrace for cpu 1 CPU: 1 PID: 8732 Comm: syz-executor.0 Not tainted 5.15.0-rc2-next-20210922-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1ae/0x220 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x25e/0x3f0 kernel/rcu/tree_stall.h:343 print_cpu_stall kernel/rcu/tree_stall.h:627 [inline] check_cpu_stall kernel/rcu/tree_stall.h:711 [inline] rcu_pending kernel/rcu/tree.c:3878 [inline] rcu_sched_clock_irq.cold+0x9d/0x746 kernel/rcu/tree.c:2597 update_process_times+0x16d/0x200 kernel/time/timer.c:1785 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226 tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1428 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x1c0/0xe50 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x38/0x70 kernel/locking/spinlock.c:194 Code: 74 24 10 e8 ca 5b 26 f8 48 89 ef e8 12 d2 26 f8 81 e3 00 02 00 00 75 25 9c 58 f6 c4 02 75 2d 48 85 db 74 01 fb bf 01 00 00 00 93 6f 1a f8 65 8b 05 dc 49 cd 76 85 c0 74 0a 5b 5d c3 e8 d0 46 RSP: 0018:ffffc90017ba7720 EFLAGS: 00000206 RAX: 0000000000000002 RBX: 0000000000000200 RCX: 1ffffffff1faaec6 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001 RBP: ffff88806bc68c40 R08: 0000000000000001 R09: ffffffff8fd0ca07 R10: 0000000000000001 R11: 0000000000000000 R12: ffff88803be28060 R13: ffffc90017ba7828 R14: dffffc0000000000 R15: ffff88803be28000 mptcp_wait_data net/mptcp/protocol.c:1774 [inline] mptcp_recvmsg+0x10fd/0x27b0 net/mptcp/protocol.c:2080 inet6_recvmsg+0x11b/0x5e0 net/ipv6/af_inet6.c:659 sock_recvmsg_nosec net/socket.c:944 [inline] ____sys_recvmsg+0x527/0x600 net/socket.c:2626 ___sys_recvmsg+0x127/0x200 net/socket.c:2670 do_recvmmsg+0x24d/0x6d0 net/socket.c:2764 __sys_recvmmsg net/socket.c:2843 [inline] __do_sys_recvmmsg net/socket.c:2866 [inline] __se_sys_recvmmsg net/socket.c:2859 [inline] __x64_sys_recvmmsg+0x20b/0x260 net/socket.c:2859 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f58847eb709 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 RSP: 002b:00007f5881d62188 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00007f58848eff60 RCX: 00007f58847eb709 RDX: 0000000000000002 RSI: 00000000200017c0 RDI: 0000000000000005 RBP: 00007f5884845cb4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000100 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd391c271f R14: 00007f5881d62300 R15: 0000000000022000 ---------------- Code disassembly (best guess): 0: c0 0f 85 rorb $0x85,(%rdi) 3: ca 00 00 lret $0x0 6: 00 65 4c add %ah,0x4c(%rbp) 9: 8b 24 25 40 70 02 00 mov 0x27040,%esp 10: 41 8b 94 24 64 0a 00 mov 0xa64(%r12),%edx 17: 00 18: 85 d2 test %edx,%edx 1a: 0f 85 b1 00 00 00 jne 0xd1 20: 48 89 fd mov %rdi,%rbp 23: 41 89 f6 mov %esi,%r14d 26: 9c pushfq 27: 8f 04 24 popq (%rsp) * 2a: fa cli <-- trapping instruction 2b: 48 c7 c7 60 01 8c 89 mov $0xffffffff898c0160,%rdi 32: 31 db xor %ebx,%ebx 34: e8 fd 0d 00 00 callq 0xe36 39: 41 rex.B 3a: 8b .byte 0x8b 3b: 84 24 60 test %ah,(%rax,%riz,2) 3e: 0a 00 or (%rax),%al