rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (10499 ticks this GP) idle=205/1/0x4000000000000000 softirq=13779/13779 fqs=11 (t=10501 jiffies g=19689 q=100) rcu: rcu_preempt kthread starved for 10479 jiffies! g19689 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:1959 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2132 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: 10065 Comm: syz-executor.2 Not tainted 5.15.0-rc3-next-20210927-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:mark_lock+0x182/0x17b0 kernel/locking/lockdep.c:4612 Code: 48 c7 43 10 00 00 00 00 48 8b 84 24 10 01 00 00 65 48 2b 04 25 28 00 00 00 0f 85 c3 11 00 00 48 81 c4 18 01 00 00 44 89 d0 5b <5d> 41 5c 41 5d 41 5e 41 5f c3 48 8d 7e 22 48 89 f8 48 c1 e8 03 0f RSP: 0018:ffffc90000007c28 EFLAGS: 00000092 RAX: 0000000000000001 RBX: ffff88807ae5274c RCX: 1ffffffff1fa21e6 RDX: dffffc0000000000 RSI: 0000000000000200 RDI: ffffffff8fd10f30 RBP: 0000000000000200 R08: 0000000000000000 R09: ffffffff8fd0d94f R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000009 R13: ffff88807ae527e0 R14: 0000000000000042 R15: ffff88807ae52800 FS: 00007f19052ab700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2ce2c000 CR3: 0000000070f0c000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: mark_usage kernel/locking/lockdep.c:4514 [inline] __lock_acquire+0x8a7/0x54a0 kernel/locking/lockdep.c:4969 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] ktime_get+0x7c/0x470 kernel/time/timekeeping.c:827 clockevents_program_event+0x141/0x370 kernel/time/clockevents.c:326 tick_program_event+0xac/0x140 kernel/time/tick-oneshot.c:44 hrtimer_interrupt+0x36e/0x790 kernel/time/hrtimer.c:1824 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:lock_acquire+0x1ef/0x510 kernel/locking/lockdep.c:5593 Code: ef a6 7e 83 f8 01 0f 85 b4 02 00 00 9c 58 f6 c4 02 0f 85 9f 02 00 00 48 83 7c 24 08 00 74 01 fb 48 b8 00 00 00 00 00 fc ff df <48> 01 c3 48 c7 03 00 00 00 00 48 c7 43 08 00 00 00 00 48 8b 84 24 RSP: 0018:ffffc90005477600 EFLAGS: 00000206 RAX: dffffc0000000000 RBX: 1ffff92000a8eec2 RCX: ffffffff815b378f RDX: 1ffff1100f5ca4ec RSI: 0000000000000201 RDI: 0000000000000000 RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff8fd0d9cf R10: fffffbfff1fa1b39 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: ffff8881485831a0 R15: 0000000000000000 __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_fast+0x5d/0x100 net/core/sock.c:3232 mptcp_subflow_cleanup_rbuf net/mptcp/protocol.c:465 [inline] mptcp_cleanup_rbuf net/mptcp/protocol.c:499 [inline] mptcp_recvmsg+0xad3/0x27b0 net/mptcp/protocol.c:2069 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: 0033:0x7f1907d34709 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:00007f19052ab188 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00007f1907e38f60 RCX: 00007f1907d34709 RDX: 0000000000000002 RSI: 00000000200017c0 RDI: 0000000000000004 RBP: 00007f1907d8ecb4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000100 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fff4abb7fef R14: 00007f19052ab300 R15: 0000000000022000 NMI backtrace for cpu 1 CPU: 1 PID: 10060 Comm: syz-executor.0 Not tainted 5.15.0-rc3-next-20210927-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:3882 [inline] rcu_sched_clock_irq.cold+0x9d/0x746 kernel/rcu/tree.c:2601 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:lock_acquire+0x1ef/0x510 kernel/locking/lockdep.c:5593 Code: ef a6 7e 83 f8 01 0f 85 b4 02 00 00 9c 58 f6 c4 02 0f 85 9f 02 00 00 48 83 7c 24 08 00 74 01 fb 48 b8 00 00 00 00 00 fc ff df <48> 01 c3 48 c7 03 00 00 00 00 48 c7 43 08 00 00 00 00 48 8b 84 24 RSP: 0018:ffffc900054af620 EFLAGS: 00000206 RAX: dffffc0000000000 RBX: 1ffff92000a95ec6 RCX: ffffffff815b378f RDX: 1ffff11003878c2c RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff8fd0da07 R10: fffffbfff1fa1b40 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: ffff8880843318a0 R15: 0000000000000000 lock_sock_nested+0x2f/0xf0 net/core/sock.c:3183 lock_sock include/net/sock.h:1600 [inline] mptcp_wait_data net/mptcp/protocol.c:1812 [inline] mptcp_recvmsg+0x1047/0x27b0 net/mptcp/protocol.c:2122 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: 0033:0x7fbd99ff9709 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:00007fbd97570188 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00007fbd9a0fdf60 RCX: 00007fbd99ff9709 RDX: 0000000000000002 RSI: 00000000200017c0 RDI: 0000000000000004 RBP: 00007fbd9a053cb4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000100 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffcc1c6181f R14: 00007fbd97570300 R15: 0000000000022000 ---------------- Code disassembly (best guess): 0: 48 c7 43 10 00 00 00 movq $0x0,0x10(%rbx) 7: 00 8: 48 8b 84 24 10 01 00 mov 0x110(%rsp),%rax f: 00 10: 65 48 2b 04 25 28 00 sub %gs:0x28,%rax 17: 00 00 19: 0f 85 c3 11 00 00 jne 0x11e2 1f: 48 81 c4 18 01 00 00 add $0x118,%rsp 26: 44 89 d0 mov %r10d,%eax 29: 5b pop %rbx * 2a: 5d pop %rbp <-- trapping instruction 2b: 41 5c pop %r12 2d: 41 5d pop %r13 2f: 41 5e pop %r14 31: 41 5f pop %r15 33: c3 retq 34: 48 8d 7e 22 lea 0x22(%rsi),%rdi 38: 48 89 f8 mov %rdi,%rax 3b: 48 c1 e8 03 shr $0x3,%rax 3f: 0f .byte 0xf