rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (1 GPs behind) idle=e73/1/0x4000000000000000 softirq=25306/25307 fqs=0 (t=10500 jiffies g=40009 q=57) rcu: rcu_preempt kthread starved for 10500 jiffies! g40009 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: 13065 Comm: syz-executor.0 Not tainted 5.15.0-rc2-next-20210920-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__lock_acquire+0x1ec/0x54a0 kernel/locking/lockdep.c:4925 Code: f6 4c 8d 24 c5 00 00 00 00 74 4a 4a 8d 4c 21 d8 48 be 00 00 00 00 00 fc ff df 48 8d 79 20 49 89 f8 49 c1 e8 03 41 0f b6 34 30 <40> 84 f6 74 0a 40 80 fe 03 0f 8e 94 3b 00 00 0f b7 71 20 81 e6 ff RSP: 0018:ffffc900000079c0 EFLAGS: 00000802 RAX: 0000000000000005 RBX: ffffffff8b99fd08 RCX: ffff888073e26168 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff888073e26188 RBP: 0000000000000000 R08: 1ffff1100e7c4c31 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000028 R13: ffff888073e25700 R14: 0000000000000002 R15: 0000000000000001 FS: 00007f0a40c96700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0a4376c1e8 CR3: 0000000088e5f000 CR4: 00000000001526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire kernel/locking/lockdep.c:5625 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5590 seqcount_lockdep_reader_access include/linux/seqlock.h:103 [inline] timekeeping_get_delta kernel/time/timekeeping.c:252 [inline] timekeeping_get_ns kernel/time/timekeeping.c:386 [inline] ktime_get+0x147/0x470 kernel/time/timekeeping.c:829 hrtimer_forward_now include/linux/hrtimer.h:506 [inline] perf_swevent_hrtimer+0x246/0x3f0 kernel/events/core.c:10546 __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:check_kcov_mode kernel/kcov.c:163 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x7/0x60 kernel/kcov.c:197 Code: fd ff ff b9 ff ff ff ff ba 08 00 00 00 4d 8b 03 48 0f bd ca 49 8b 45 00 48 63 c9 e9 64 ff ff ff 0f 1f 00 65 8b 05 a9 ce 8b 7e <89> c1 48 8b 34 24 81 e1 00 01 00 00 65 48 8b 14 25 40 f0 01 00 a9 RSP: 0018:ffffc9000318f658 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff888073e25700 RDX: 0000000000000000 RSI: ffff888073e25700 RDI: 0000000000000003 RBP: ffff888081210bc0 R08: 0000000000000001 R09: 0000000000000000 R10: ffffffff88e8ccb6 R11: 0000000000000000 R12: dffffc0000000000 R13: ffff888081211538 R14: 1ffff92000631ed4 R15: ffff888081210bc0 mptcp_flush_join_list+0x5f/0x90 net/mptcp/protocol.c:789 __mptcp_move_skbs+0x7c/0x6c0 net/mptcp/protocol.c:1952 mptcp_recvmsg+0x168f/0x27b0 net/mptcp/protocol.c:2029 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: 0033:0x7f0a4371f739 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:00007f0a40c96188 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00007f0a43823f80 RCX: 00007f0a4371f739 RDX: 0000000000000002 RSI: 00000000200017c0 RDI: 0000000000000005 RBP: 00007f0a43779cc4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000100 R11: 0000000000000246 R12: 00007f0a43823f80 R13: 00007fff2fed36df R14: 00007f0a40c96300 R15: 0000000000022000 NMI backtrace for cpu 1 CPU: 1 PID: 13058 Comm: syz-executor.3 Not tainted 5.15.0-rc2-next-20210920-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:native_save_fl arch/x86/include/asm/irqflags.h:29 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:70 [inline] RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:106 [inline] RIP: 0010:lock_is_held_type+0x51/0x140 kernel/locking/lockdep.c:5664 Code: cf 76 85 c0 0f 85 ca 00 00 00 65 4c 8b 24 25 40 f0 01 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 fa 48 c7 c7 60 00 8c 89 31 db e8 fd 0d 00 00 41 8b 84 24 RSP: 0018:ffffc900031bf5e8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000001 RDX: 0000000000000000 RSI: 00000000ffffffff RDI: ffffffff8b9808a0 RBP: ffffffff8b9808a0 R08: 0000000000000001 R09: ffff888080730877 R10: ffffed10100e610e R11: 0000000000000443 R12: ffff88803a5d8000 R13: 00000000ffffffff R14: 00000000ffffffff R15: ffff888080730000 lock_is_held include/linux/lockdep.h:283 [inline] ___might_sleep+0x3a/0x2c0 kernel/sched/core.c:9476 mptcp_flush_join_list+0x3e/0x90 net/mptcp/protocol.c:787 __mptcp_move_skbs+0x7c/0x6c0 net/mptcp/protocol.c:1952 mptcp_recvmsg+0x168f/0x27b0 net/mptcp/protocol.c:2029 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: 0033:0x7f9ff4fdc739 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:00007f9ff2553188 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00007f9ff50e0f80 RCX: 00007f9ff4fdc739 RDX: 0000000000000002 RSI: 00000000200017c0 RDI: 0000000000000005 RBP: 00007f9ff5036cc4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000100 R11: 0000000000000246 R12: 00007f9ff50e0f80 R13: 00007ffd79b6520f R14: 00007f9ff2553300 R15: 0000000000022000 ---------------- Code disassembly (best guess): 0: f6 4c 8d 24 c5 testb $0xc5,0x24(%rbp,%rcx,4) 5: 00 00 add %al,(%rax) 7: 00 00 add %al,(%rax) 9: 74 4a je 0x55 b: 4a 8d 4c 21 d8 lea -0x28(%rcx,%r12,1),%rcx 10: 48 be 00 00 00 00 00 movabs $0xdffffc0000000000,%rsi 17: fc ff df 1a: 48 8d 79 20 lea 0x20(%rcx),%rdi 1e: 49 89 f8 mov %rdi,%r8 21: 49 c1 e8 03 shr $0x3,%r8 25: 41 0f b6 34 30 movzbl (%r8,%rsi,1),%esi * 2a: 40 84 f6 test %sil,%sil <-- trapping instruction 2d: 74 0a je 0x39 2f: 40 80 fe 03 cmp $0x3,%sil 33: 0f 8e 94 3b 00 00 jle 0x3bcd 39: 0f b7 71 20 movzwl 0x20(%rcx),%esi 3d: 81 .byte 0x81 3e: e6 ff out %al,$0xff