rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (1 GPs behind) idle=565/1/0x4000000000000000 softirq=13382/13383 fqs=0 (t=10500 jiffies g=18413 q=47) rcu: rcu_preempt kthread starved for 10500 jiffies! g18413 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: 9692 Comm: syz-executor.3 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:__lock_acquire+0x298/0x54a0 kernel/locking/lockdep.c:4950 Code: 24 20 48 b8 00 00 00 00 00 fc ff df 80 3c 02 00 0f 85 43 3b 00 00 48 8b 84 24 28 01 00 00 49 8d 7c 24 10 48 89 fa 48 c1 ea 03 <49> 89 44 24 08 48 b8 00 00 00 00 00 fc ff df 80 3c 02 00 0f 85 6b RSP: 0018:ffffc9000488f4c8 EFLAGS: 00000802 RAX: ffffffff8714630d RBX: ffff888082ec8c60 RCX: 0000000000000637 RDX: 1ffff11006e56154 RSI: 0000000000000636 RDI: ffff8880372b0aa0 RBP: 0000000000000000 R08: 1ffff11006e56151 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880372b0a90 R13: ffff8880372b0000 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f89f23ce700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2de26000 CR3: 000000006e787000 CR4: 00000000001526e0 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 __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] lock_sock_nested+0x5d/0xf0 net/core/sock.c:3186 lock_sock include/net/sock.h:1612 [inline] mptcp_wait_data net/mptcp/protocol.c:1770 [inline] mptcp_recvmsg+0x1047/0x27b0 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: 0033:0x7f89f4e57709 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:00007f89f23ce188 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00007f89f4f5bf60 RCX: 00007f89f4e57709 RDX: 0000000000000002 RSI: 00000000200017c0 RDI: 0000000000000004 RBP: 00007f89f4eb1cb4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000100 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd72efafaf R14: 00007f89f23ce300 R15: 0000000000022000 NMI backtrace for cpu 0 CPU: 0 PID: 9690 Comm: syz-executor.5 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:__mptcp_rmem net/mptcp/protocol.h:310 [inline] RIP: 0010:mptcp_cleanup_rbuf net/mptcp/protocol.c:493 [inline] RIP: 0010:mptcp_recvmsg+0x8f0/0x27b0 net/mptcp/protocol.c:2027 Code: e8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 1f 1d 00 00 41 8b 87 08 02 00 00 89 44 24 20 4c 89 e0 48 c1 e8 03 42 0f b6 14 30 <4c> 89 e0 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 e6 1c 00 00 41 RSP: 0018:ffffc900044b7738 EFLAGS: 00000a03 RAX: 1ffff110105d910d RBX: 0000000000010000 RCX: ffffffff88e92cf8 RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff888082ec8208 RBP: ffff888082ec8208 R08: 0000000000000000 R09: ffff888082ec820b R10: ffffed10105d9041 R11: 0000000000000000 R12: ffff888082ec886c R13: 0000000000000001 R14: dffffc0000000000 R15: ffff888082ec8000 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: 0033:0x7fd07ee8b709 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:00007fd07c3e1188 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00007fd07ef90020 RCX: 00007fd07ee8b709 RDX: 0000000000000002 RSI: 00000000200017c0 RDI: 0000000000000003 RBP: 00007fd07eee5cb4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000100 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fffea0b47ef R14: 00007fd07c3e1300 R15: 0000000000022000 ---------------- Code disassembly (best guess): 0: 24 20 and $0x20,%al 2: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 9: fc ff df c: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) 10: 0f 85 43 3b 00 00 jne 0x3b59 16: 48 8b 84 24 28 01 00 mov 0x128(%rsp),%rax 1d: 00 1e: 49 8d 7c 24 10 lea 0x10(%r12),%rdi 23: 48 89 fa mov %rdi,%rdx 26: 48 c1 ea 03 shr $0x3,%rdx * 2a: 49 89 44 24 08 mov %rax,0x8(%r12) <-- trapping instruction 2f: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 36: fc ff df 39: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) 3d: 0f .byte 0xf 3e: 85 .byte 0x85 3f: 6b .byte 0x6b