rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (1 GPs behind) idle=3db/1/0x4000000000000000 softirq=173044/173045 fqs=16 (t=10502 jiffies g=236869 q=613) rcu: rcu_preempt kthread starved for 10468 jiffies! g236869 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:27208 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4969 [inline] __schedule+0xa9a/0x4940 kernel/sched/core.c:6250 schedule+0xd2/0x260 kernel/sched/core.c:6323 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: 18568 Comm: syz-executor.2 Not tainted 5.15.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:check_kcov_mode+0x2c/0x40 kernel/kcov.c:177 Code: 05 39 ae 8a 7e 89 c2 81 e2 00 01 00 00 a9 00 01 ff 00 74 10 31 c0 85 d2 74 15 8b 96 a4 15 00 00 85 d2 74 0b 8b 86 80 15 00 00 <39> f8 0f 94 c0 c3 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 31 c0 RSP: 0018:ffffc90019167850 EFLAGS: 00000246 RAX: 0000000000000002 RBX: ffff88816654a820 RCX: ffff88807c500000 RDX: 0000000000000000 RSI: ffff88807c500000 RDI: 0000000000000003 RBP: ffffc90019167948 R08: 0000000000000000 R09: 000000000000000a R10: ffffffff8864567b R11: 000000000000000a R12: 000000000000000a R13: 000000000000000a R14: ffffffff8d3f74a0 R15: 0000000000000001 FS: 00007f1ab8530700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555555646108 CR3: 000000016522b000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: write_comp_data kernel/kcov.c:221 [inline] __sanitizer_cov_trace_cmp2+0x22/0x80 kernel/kcov.c:255 __sctp_v6_cmp_addr+0x7b/0x520 net/sctp/ipv6.c:626 sctp_v6_cmp_addr+0x1a/0xd0 net/sctp/ipv6.c:662 sctp_bind_addr_state+0x103/0x1d0 net/sctp/bind_addr.c:407 sctp_copy_local_addr_list+0x1fe/0x4f0 net/sctp/protocol.c:162 sctp_copy_one_addr net/sctp/bind_addr.c:460 [inline] sctp_bind_addr_copy+0xde/0x460 net/sctp/bind_addr.c:56 sctp_connect_new_asoc+0x1cd/0x770 net/sctp/socket.c:1092 sctp_sendmsg_new_asoc net/sctp/socket.c:1690 [inline] sctp_sendmsg+0x13bc/0x1d30 net/sctp/socket.c:2000 inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:819 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:724 __sys_sendto+0x21c/0x320 net/socket.c:2036 __do_sys_sendto net/socket.c:2048 [inline] __se_sys_sendto net/socket.c:2044 [inline] __x64_sys_sendto+0xdd/0x1b0 net/socket.c:2044 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: 0033:0x7f1abb080ae9 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:00007f1ab8530188 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f1abb1943e0 RCX: 00007f1abb080ae9 RDX: 000000000000002a RSI: 0000000020000080 RDI: 0000000000000003 RBP: 00007f1abb0daf6d R08: 00000000200000c0 R09: 000000000000001c R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffdb6f8a92f R14: 00007f1ab8530300 R15: 0000000000022000 NMI backtrace for cpu 0 CPU: 0 PID: 18539 Comm: syz-executor.2 Not tainted 5.15.0-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:1421 __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:write_comp_data kernel/kcov.c:221 [inline] RIP: 0010:__sanitizer_cov_trace_const_cmp8+0x18/0x70 kernel/kcov.c:294 Code: 48 89 74 38 e8 4e 89 54 c8 20 48 89 10 c3 0f 1f 40 00 49 89 f8 bf 03 00 00 00 4c 8b 14 24 48 89 f1 65 48 8b 34 25 40 70 02 00 a3 f8 ff ff 84 c0 74 48 48 8b 86 88 15 00 00 8b b6 84 15 00 00 RSP: 0018:ffffc90018f97860 EFLAGS: 00000206 RAX: dffffc0000000000 RBX: ffff88815651d120 RCX: 2500000000000000 RDX: 1ffff920031f2f2b RSI: ffff8880a9d31d00 RDI: 0000000000000003 RBP: ffffc90018f97948 R08: 0000000000000000 R09: 000000000000000a R10: ffffffff886458ad R11: 000000000000000a R12: 2500000000000000 R13: ffff88815651d128 R14: 0000000000000000 R15: 0000000000000001 __sctp_v6_cmp_addr+0x2ad/0x520 net/sctp/ipv6.c:644 sctp_v6_cmp_addr+0x1a/0xd0 net/sctp/ipv6.c:662 sctp_bind_addr_state+0x103/0x1d0 net/sctp/bind_addr.c:407 sctp_copy_local_addr_list+0x1fe/0x4f0 net/sctp/protocol.c:162 sctp_copy_one_addr net/sctp/bind_addr.c:460 [inline] sctp_bind_addr_copy+0xde/0x460 net/sctp/bind_addr.c:56 sctp_connect_new_asoc+0x1cd/0x770 net/sctp/socket.c:1092 sctp_sendmsg_new_asoc net/sctp/socket.c:1690 [inline] sctp_sendmsg+0x13bc/0x1d30 net/sctp/socket.c:2000 inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:819 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:724 __sys_sendto+0x21c/0x320 net/socket.c:2036 __do_sys_sendto net/socket.c:2048 [inline] __se_sys_sendto net/socket.c:2044 [inline] __x64_sys_sendto+0xdd/0x1b0 net/socket.c:2044 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: 0033:0x7f1abb080ae9 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:00007f1ab85d5188 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f1abb194020 RCX: 00007f1abb080ae9 RDX: 000000000000002a RSI: 0000000020000080 RDI: 0000000000000004 RBP: 00007f1abb0daf6d R08: 00000000200000c0 R09: 000000000000001c R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffdb6f8a92f R14: 00007f1ab85d5300 R15: 0000000000022000 ---------------- Code disassembly (best guess): 0: 05 39 ae 8a 7e add $0x7e8aae39,%eax 5: 89 c2 mov %eax,%edx 7: 81 e2 00 01 00 00 and $0x100,%edx d: a9 00 01 ff 00 test $0xff0100,%eax 12: 74 10 je 0x24 14: 31 c0 xor %eax,%eax 16: 85 d2 test %edx,%edx 18: 74 15 je 0x2f 1a: 8b 96 a4 15 00 00 mov 0x15a4(%rsi),%edx 20: 85 d2 test %edx,%edx 22: 74 0b je 0x2f 24: 8b 86 80 15 00 00 mov 0x1580(%rsi),%eax * 2a: 39 f8 cmp %edi,%eax <-- trapping instruction 2c: 0f 94 c0 sete %al 2f: c3 retq 30: 66 66 2e 0f 1f 84 00 data16 nopw %cs:0x0(%rax,%rax,1) 37: 00 00 00 00 3b: 0f 1f 00 nopl (%rax) 3e: 31 c0 xor %eax,%eax