rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-....: (1 GPs behind) idle=98f/1/0x4000000000000000 softirq=127987/127988 fqs=5169 (t=10502 jiffies g=233437 q=1420) NMI backtrace for cpu 0 CPU: 0 PID: 13905 Comm: syz-executor.0 Not tainted 5.15.0-rc2-next-20210923-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_cmp1+0x0/0x80 kernel/kcov.c:269 Code: 39 fe 72 1f 48 83 c2 01 4c 89 44 38 e8 48 c7 44 38 e0 06 00 00 00 48 89 4c 38 f0 4e 89 54 c8 20 48 89 10 c3 66 0f 1f 44 00 00 <53> 41 89 fb 41 89 f1 bf 03 00 00 00 65 48 8b 0c 25 40 70 02 00 48 RSP: 0018:ffffc90003c5f658 EFLAGS: 00000246 RAX: 0000000000040000 RBX: 0000000000000000 RCX: ffffc90017919000 RDX: 0000000000040000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff8880266b3ac0 R08: 0000000000000001 R09: 0000000000000000 R10: ffffffff88e85c76 R11: 0000000000000000 R12: dffffc0000000000 R13: ffff8880266b4438 R14: 1ffff9200078bed4 R15: ffff8880266b3ac0 mptcp_flush_join_list+0x69/0x90 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: 0033:0x7fc51a740709 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:00007fc517cb7188 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00007fc51a844f60 RCX: 00007fc51a740709 RDX: 0000000000000002 RSI: 00000000200017c0 RDI: 0000000000000003 RBP: 00007fc51a79acb4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000100 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fff27cbfb4f R14: 00007fc517cb7300 R15: 0000000000022000 ---------------- Code disassembly (best guess): 0: 39 fe cmp %edi,%esi 2: 72 1f jb 0x23 4: 48 83 c2 01 add $0x1,%rdx 8: 4c 89 44 38 e8 mov %r8,-0x18(%rax,%rdi,1) d: 48 c7 44 38 e0 06 00 movq $0x6,-0x20(%rax,%rdi,1) 14: 00 00 16: 48 89 4c 38 f0 mov %rcx,-0x10(%rax,%rdi,1) 1b: 4e 89 54 c8 20 mov %r10,0x20(%rax,%r9,8) 20: 48 89 10 mov %rdx,(%rax) 23: c3 retq 24: 66 0f 1f 44 00 00 nopw 0x0(%rax,%rax,1) * 2a: 53 push %rbx <-- trapping instruction 2b: 41 89 fb mov %edi,%r11d 2e: 41 89 f1 mov %esi,%r9d 31: bf 03 00 00 00 mov $0x3,%edi 36: 65 48 8b 0c 25 40 70 mov %gs:0x27040,%rcx 3d: 02 00 3f: 48 rex.W