batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (-224) batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (-224) batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (-224) INFO: rcu_preempt self-detected stall on CPU 1-...: (10498 ticks this GP) idle=cc6/140000000000001/0 softirq=8800/8800 fqs=0 (t=10500 jiffies g=1177 c=1176 q=48) rcu_preempt kthread starved for 10500 jiffies! g1177 c1176 f0x0 RCU_GP_WAIT_FQS(3) ->state=0x402 ->cpu=1 rcu_preempt I29720 8 2 0x80000000 Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x824/0x1ee0 kernel/sched/core.c:3384 schedule+0x7f/0x1b0 kernel/sched/core.c:3428 schedule_timeout+0x41f/0xcc0 kernel/time/timer.c:1747 rcu_gp_kthread+0xb69/0x1df0 kernel/rcu/tree.c:2255 kthread+0x338/0x400 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 NMI backtrace for cpu 1 CPU: 1 PID: 7081 Comm: syz-executor.3 Not tainted 4.14.216-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x14b/0x1e7 lib/dump_stack.c:58 nmi_cpu_backtrace.cold.0+0x3c/0x78 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0xf5/0x120 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_single_cpu_backtrace include/linux/nmi.h:158 [inline] rcu_dump_cpu_stacks+0x172/0x1bf kernel/rcu/tree.c:1396 print_cpu_stall kernel/rcu/tree.c:1542 [inline] check_cpu_stall kernel/rcu/tree.c:1610 [inline] __rcu_pending kernel/rcu/tree.c:3390 [inline] rcu_pending kernel/rcu/tree.c:3452 [inline] rcu_check_callbacks.cold.59+0x415/0xced kernel/rcu/tree.c:2792 update_process_times+0x2a/0x60 kernel/time/timer.c:1591 tick_sched_handle.isra.5+0x6f/0x140 kernel/time/tick-sched.c:165 tick_sched_timer+0x39/0xf0 kernel/time/tick-sched.c:1223 __run_hrtimer kernel/time/hrtimer.c:1223 [inline] __hrtimer_run_queues+0x279/0xad0 kernel/time/hrtimer.c:1287 hrtimer_interrupt+0x1ae/0x600 kernel/time/hrtimer.c:1321 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1075 [inline] smp_apic_timer_interrupt+0x11f/0x5d0 arch/x86/kernel/apic/apic.c:1100 apic_timer_interrupt+0x9a/0xa0 arch/x86/entry/entry_64.S:793 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:779 [inline] RIP: 0010:lock_release+0x446/0x820 kernel/locking/lockdep.c:4020 RSP: 0018:ffff8881d47dee00 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff10 RAX: dffffc0000000000 RBX: 1ffff1103a8fbdc3 RCX: 1ffff1103b38b98f RDX: 1ffffffff0fe2bc1 RSI: 0000000000000003 RDI: 0000000000000286 RBP: ffff8881d47deea0 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000050 R11: ffff8881d9c5c400 R12: ffff8881d9c5c400 R13: 0000000000000002 R14: ffff8881d9c5c400 R15: ffff8881d9c5cc80 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:174 [inline] _raw_spin_unlock_bh+0x1a/0x40 kernel/locking/spinlock.c:208 spin_unlock_bh include/linux/spinlock.h:362 [inline] batadv_tt_local_purge_pending_clients+0x22a/0x320 net/batman-adv/translation-table.c:3901 batadv_tt_local_resize_to_mtu+0x82/0xe0 net/batman-adv/translation-table.c:4167 batadv_update_min_mtu net/batman-adv/hard-interface.c:619 [inline] batadv_hardif_activate_interface.part.4.cold.12+0xb1/0x2b7 net/batman-adv/hard-interface.c:646 batadv_hardif_activate_interface net/batman-adv/hard-interface.c:799 [inline] batadv_hardif_enable_interface+0xaa8/0xab0 net/batman-adv/hard-interface.c:791 batadv_softif_slave_add+0x7f/0xd0 net/batman-adv/soft-interface.c:889 do_set_master+0x163/0x1f0 net/core/rtnetlink.c:1961 do_setlink+0x93e/0x2c80 net/core/rtnetlink.c:2098 rtnl_newlink+0xe5a/0x13a0 net/core/rtnetlink.c:2660 rtnetlink_rcv_msg+0x34c/0x9e0 net/core/rtnetlink.c:4316 netlink_rcv_skb+0x12f/0x3b0 net/netlink/af_netlink.c:2433 rtnetlink_rcv+0x10/0x20 net/core/rtnetlink.c:4328 netlink_unicast_kernel net/netlink/af_netlink.c:1287 [inline] netlink_unicast+0x40b/0x610 net/netlink/af_netlink.c:1313 netlink_sendmsg+0x657/0xc60 net/netlink/af_netlink.c:1878 sock_sendmsg_nosec net/socket.c:646 [inline] sock_sendmsg+0xac/0xf0 net/socket.c:656 ___sys_sendmsg+0x625/0x920 net/socket.c:2062 __sys_sendmsg+0xc1/0x140 net/socket.c:2096 SYSC_sendmsg net/socket.c:2107 [inline] SyS_sendmsg+0xd/0x20 net/socket.c:2103 do_syscall_64+0x1c7/0x5b0 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x45c1f9 RSP: 002b:00007f3798397c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 000000000002b580 RCX: 000000000045c1f9 RDX: 0000000000000000 RSI: 0000000020000140 RDI: 0000000000000004 RBP: 000000000078bf40 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078bf0c R13: 00007fff75a3170f R14: 00007f37983989c0 R15: 000000000078bf0c net_ratelimit: 7178 callbacks suppressed batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (-224) batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (-224) batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (-224) batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (-224) batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (-224) batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (-224) batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (-224) batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (-224) batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (-224) batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (-224) net_ratelimit: 7496 callbacks suppressed batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (-224) batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (-224) batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (-224) batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (-224) batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (-224) batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (-224) batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (-224) batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (-224) batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (-224) batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (-224)