rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (1 GPs behind) idle=c3a/1/0x4000000000000000 softirq=19927/19928 fqs=15 (t=10501 jiffies g=30101 q=118) rcu: rcu_preempt kthread starved for 10471 jiffies! g30101 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=1 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. rcu: RCU grace-period kthread stack dump: rcu_preempt I29256 10 2 0x00004000 Call Trace: context_switch kernel/sched/core.c:3453 [inline] __schedule+0x8e1/0x1eb0 kernel/sched/core.c:4178 schedule+0xd0/0x2a0 kernel/sched/core.c:4253 schedule_timeout+0x148/0x250 kernel/time/timer.c:1897 rcu_gp_fqs_loop kernel/rcu/tree.c:1874 [inline] rcu_gp_kthread+0xae5/0x1b50 kernel/rcu/tree.c:2044 kthread+0x3b5/0x4a0 kernel/kthread.c:291 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293 NMI backtrace for cpu 0 CPU: 0 PID: 12556 Comm: syz-executor.3 Not tainted 5.8.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x18f/0x20d lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x70/0xb1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1b3/0x223 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x194/0x1cf kernel/rcu/tree_stall.h:320 print_cpu_stall kernel/rcu/tree_stall.h:553 [inline] check_cpu_stall kernel/rcu/tree_stall.h:627 [inline] rcu_pending kernel/rcu/tree.c:3489 [inline] rcu_sched_clock_irq.cold+0x5b3/0xccc kernel/rcu/tree.c:2504 update_process_times+0x25/0x60 kernel/time/timer.c:1726 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:176 tick_sched_timer+0x108/0x290 kernel/time/tick-sched.c:1320 __run_hrtimer kernel/time/hrtimer.c:1520 [inline] __hrtimer_run_queues+0x1d5/0xfc0 kernel/time/hrtimer.c:1584 hrtimer_interrupt+0x32a/0x930 kernel/time/hrtimer.c:1646 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1080 [inline] __sysvec_apic_timer_interrupt+0x142/0x5e0 arch/x86/kernel/apic/apic.c:1097 asm_call_on_stack+0xf/0x20 arch/x86/entry/entry_64.S:711 __run_on_irqstack arch/x86/include/asm/irq_stack.h:22 [inline] run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:48 [inline] sysvec_apic_timer_interrupt+0xe0/0x120 arch/x86/kernel/apic/apic.c:1091 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:596 RIP: 0010:batadv_tt_local_purge+0xec/0x370 net/batman-adv/translation-table.c:1442 Code: 4c 01 f8 48 89 44 24 30 e8 21 2b a7 f9 48 8b 44 24 28 80 38 00 0f 85 55 02 00 00 48 8b 44 24 08 44 89 f3 48 8b 00 48 8d 2c d8 <48> 8b 44 24 30 80 38 00 0f 85 29 02 00 00 48 8b 44 24 08 48 c1 e3 RSP: 0018:ffffc9000435f600 EFLAGS: 00000246 RAX: ffff88804b9d0000 RBX: 00000000000003cc RCX: ffffc9000f240000 RDX: 0000000000040000 RSI: ffffffff87cc8c3f RDI: 0000000000000004 RBP: ffff88804b9d1e60 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000400 R11: 0000000000000000 R12: 0000000000000100 R13: ffff888093237a18 R14: 00000000000003cc R15: dffffc0000000000 batadv_tt_local_resize_to_mtu+0x8e/0x130 net/batman-adv/translation-table.c:4197 batadv_netlink_set_mesh+0x766/0x1400 net/batman-adv/netlink.c:499 genl_family_rcv_msg_doit net/netlink/genetlink.c:691 [inline] genl_family_rcv_msg net/netlink/genetlink.c:736 [inline] genl_rcv_msg+0x61d/0x9e0 net/netlink/genetlink.c:753 netlink_rcv_skb+0x15a/0x430 net/netlink/af_netlink.c:2469 genl_rcv+0x24/0x40 net/netlink/genetlink.c:764 netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline] netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1329 netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1918 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:672 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2352 ___sys_sendmsg+0xf3/0x170 net/socket.c:2406 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2439 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:359 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45cb29 Code: Bad RIP value. RSP: 002b:00007f4f6be70c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00000000004fdee0 RCX: 000000000045cb29 RDX: 0000000000000000 RSI: 00000000200003c0 RDI: 0000000000000008 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000921 R14: 00000000004cbfff R15: 00007f4f6be716d4 NMI backtrace for cpu 0 CPU: 0 PID: 12556 Comm: syz-executor.3 Not tainted 5.8.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:write_comp_data+0x2f/0x80 kernel/kcov.c:218 Code: 05 16 4c 8e 7e 65 48 8b 34 25 00 ff 01 00 a9 00 01 ff 00 74 0f f6 c4 01 74 59 8b 86 04 14 00 00 85 c0 74 4f 8b 86 e0 13 00 00 <83> f8 03 75 44 48 8b 86 e8 13 00 00 8b b6 e4 13 00 00 4c 8b 00 48 RSP: 0018:ffffc9000435f5a8 EFLAGS: 00000046 RAX: 0000000000000002 RBX: 0000000000000000 RCX: ffffffff81796647 RDX: 0000000000000000 RSI: ffff888044ac03c0 RDI: 0000000000000005 RBP: ffffffff87cc8df5 R08: 0000000000000001 R09: ffff88804ba027c3 R10: 0000000000000000 R11: 0000000000000000 R12: ffff888044ac03c0 R13: 0000000000000001 R14: 00000000000000a0 R15: dffffc0000000000 FS: 00007f4f6be71700(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000078c000 CR3: 000000009a573000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: trace_hardirqs_off+0x27/0x210 kernel/trace/trace_preemptirq.c:78 __local_bh_enable_ip+0x119/0x250 kernel/softirq.c:171 spin_unlock_bh include/linux/spinlock.h:398 [inline] batadv_tt_local_purge+0x285/0x370 net/batman-adv/translation-table.c:1446 batadv_tt_local_resize_to_mtu+0x8e/0x130 net/batman-adv/translation-table.c:4197 batadv_netlink_set_mesh+0x766/0x1400 net/batman-adv/netlink.c:499 genl_family_rcv_msg_doit net/netlink/genetlink.c:691 [inline] genl_family_rcv_msg net/netlink/genetlink.c:736 [inline] genl_rcv_msg+0x61d/0x9e0 net/netlink/genetlink.c:753 netlink_rcv_skb+0x15a/0x430 net/netlink/af_netlink.c:2469 genl_rcv+0x24/0x40 net/netlink/genetlink.c:764 netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline] netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1329 netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1918 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:672 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2352 ___sys_sendmsg+0xf3/0x170 net/socket.c:2406 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2439 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:359 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45cb29 Code: Bad RIP value. RSP: 002b:00007f4f6be70c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00000000004fdee0 RCX: 000000000045cb29 RDX: 0000000000000000 RSI: 00000000200003c0 RDI: 0000000000000008 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000921 R14: 00000000004cbfff R15: 00007f4f6be716d4