rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (10500 ticks this GP) idle=5d9/1/0x4000000000000000 softirq=94385/94385 fqs=6 (t=10502 jiffies g=171845 q=47) rcu: rcu_preempt kthread starved for 10491 jiffies! g171845 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 4002 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:debug_smp_processor_id+0x0/0x20 lib/smp_processor_id.c:60 Code: 45 e4 89 4d 8d 86 30 08 00 00 83 e9 01 e8 bc 33 be ff 48 8b 74 24 28 48 c7 c7 40 46 e4 89 e8 ab 33 be ff e8 76 06 cd ff eb a2 <0f> 1f 44 00 00 48 c7 c6 80 46 e4 89 48 c7 c7 c0 46 e4 89 e9 a8 fe RSP: 0018:ffffc9000329f1b8 EFLAGS: 00000046 RAX: 0000000000040000 RBX: 000000000002c6a0 RCX: ffffc90017bfb000 RDX: 0000000000040000 RSI: ffffffff8194ffd2 RDI: ffff88807dcf0060 RBP: ffffc9000329f430 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff8194acac R11: 0000000000000000 R12: dffffc0000000000 R13: ffff8880b9d2c800 R14: 0000000000000001 R15: ffff88807dcf0000 FS: 00007f4849903700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b3112b000 CR3: 00000000429b3000 CR4: 00000000001506e0 Call Trace: perf_swevent_put_recursion_context kernel/events/core.c:9386 [inline] perf_tp_event+0x5be/0xb70 kernel/events/core.c:9713 perf_trace_run_bpf_submit+0x11c/0x210 kernel/events/core.c:9657 perf_trace_lock_acquire+0x34c/0x550 include/trace/events/lock.h:13 trace_lock_acquire include/trace/events/lock.h:13 [inline] lock_acquire+0x416/0x510 kernel/locking/lockdep.c:5596 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:162 add_wait_queue+0x42/0x260 kernel/sched/wait.c:23 mptcp_wait_data net/mptcp/protocol.c:1767 [inline] mptcp_recvmsg+0xf5b/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: 0033:0x7f484c38c739 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:00007f4849903188 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00007f484c490f80 RCX: 00007f484c38c739 RDX: 0000000000000002 RSI: 00000000200017c0 RDI: 0000000000000003 RBP: 00007f484c3e6cc4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000100 R11: 0000000000000246 R12: 00007f484c490f80 R13: 00007ffc6003b60f R14: 00007f4849903300 R15: 0000000000022000 NMI backtrace for cpu 0 CPU: 0 PID: 4001 Comm: syz-executor.2 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:__sanitizer_cov_trace_const_cmp4+0x6b/0x70 kernel/kcov.c:286 Code: 00 00 00 48 39 fe 72 22 44 89 c6 48 83 c2 01 48 89 4c 38 f0 48 c7 44 38 e0 05 00 00 00 48 89 74 38 e8 4e 89 54 c8 20 48 89 10 0f 1f 40 00 53 41 89 fb 41 89 f1 bf 03 00 00 00 65 48 8b 0c 25 RSP: 0018:ffffc9000328f730 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000010000 RCX: 0000000000010000 RDX: 0000000000000000 RSI: ffff88801e6d0000 RDI: 0000000000000003 RBP: ffff88802bd7a548 R08: 0000000000000000 R09: ffff88802bd7a54b R10: ffffffff88e98c81 R11: 0000000000000000 R12: ffff88802bd7abac R13: 0000000000000000 R14: dffffc0000000000 R15: ffff88802bd7a340 mptcp_cleanup_rbuf net/mptcp/protocol.c:492 [inline] mptcp_recvmsg+0x881/0x27b0 net/mptcp/protocol.c:2027 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: 0033:0x7f2363ab3739 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:00007f236102a188 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00007f2363bb7f80 RCX: 00007f2363ab3739 RDX: 0000000000000002 RSI: 00000000200017c0 RDI: 0000000000000003 RBP: 00007f2363b0dcc4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000100 R11: 0000000000000246 R12: 00007f2363bb7f80 R13: 00007ffc5805674f R14: 00007f236102a300 R15: 0000000000022000 ---------------- Code disassembly (best guess): 0: 45 e4 89 rex.RB in $0x89,%al 3: 4d 8d 86 30 08 00 00 lea 0x830(%r14),%r8 a: 83 e9 01 sub $0x1,%ecx d: e8 bc 33 be ff callq 0xffbe33ce 12: 48 8b 74 24 28 mov 0x28(%rsp),%rsi 17: 48 c7 c7 40 46 e4 89 mov $0xffffffff89e44640,%rdi 1e: e8 ab 33 be ff callq 0xffbe33ce 23: e8 76 06 cd ff callq 0xffcd069e 28: eb a2 jmp 0xffffffcc * 2a: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) <-- trapping instruction 2f: 48 c7 c6 80 46 e4 89 mov $0xffffffff89e44680,%rsi 36: 48 c7 c7 c0 46 e4 89 mov $0xffffffff89e446c0,%rdi 3d: e9 .byte 0xe9 3e: a8 fe test $0xfe,%al