INFO: rcu_preempt self-detected stall on CPU 1-...: (1 GPs behind) idle=5a6/140000000000002/0 softirq=11805/11807 fqs=1 (t=10500 jiffies g=1970 c=1969 q=613) rcu_preempt kthread starved for 10498 jiffies! g1970 c1969 f0x0 RCU_GP_WAIT_FQS(3) ->state=0x0 ->cpu=0 rcu_preempt R running task 29568 8 2 0x80000000 Call Trace: schedule+0x8d/0x1b0 kernel/sched/core.c:3428 schedule_timeout+0x43c/0xe40 kernel/time/timer.c:1746 rcu_gp_kthread+0xb8e/0x1ce0 kernel/rcu/tree.c:2255 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 NMI backtrace for cpu 1 CPU: 1 PID: 7873 Comm: syz-executor.0 Not tainted 4.14.175-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+0x13e/0x194 lib/dump_stack.c:58 nmi_cpu_backtrace.cold+0x57/0x93 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x139/0x17e lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:158 [inline] rcu_dump_cpu_stacks+0x16d/0x1b8 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+0x490/0xdaa kernel/rcu/tree.c:2792 update_process_times+0x29/0x60 kernel/time/timer.c:1590 tick_sched_handle+0x7d/0x150 kernel/time/tick-sched.c:165 tick_sched_timer+0x3e/0x120 kernel/time/tick-sched.c:1223 __run_hrtimer kernel/time/hrtimer.c:1223 [inline] __hrtimer_run_queues+0x25c/0xbb0 kernel/time/hrtimer.c:1287 hrtimer_interrupt+0x1e6/0x5e0 kernel/time/hrtimer.c:1321 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1075 [inline] smp_apic_timer_interrupt+0x117/0x5e0 arch/x86/kernel/apic/apic.c:1100 apic_timer_interrupt+0x8f/0xa0 arch/x86/entry/entry_64.S:792 RIP: 0010:unwind_next_frame+0xa40/0x17a0 arch/x86/kernel/unwind_orc.c:432 RSP: 0018:ffff8880aeb07370 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff10 RAX: dffffc0000000000 RBX: ffff8880aeb07420 RCX: 1ffff11015d60e86 RDX: ffff8880aeb07470 RSI: ffff8880aeb07328 RDI: ffff8880aeb07aa8 RBP: 1ffff11015d60e75 R08: ffffffff89412356 R09: ffff8880aeb07a68 R10: ffff8880aeb07455 R11: 0000000000058071 R12: ffffffff89412352 R13: ffff8880aeb07458 R14: ffff8880aeb07ab0 R15: 0000000000000002 __save_stack_trace+0x6b/0xd0 arch/x86/kernel/stacktrace.c:44 save_stack+0x32/0xa0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc mm/kasan/kasan.c:551 [inline] kasan_kmalloc+0xbf/0xe0 mm/kasan/kasan.c:529 __do_kmalloc_node mm/slab.c:3682 [inline] __kmalloc_node_track_caller+0x4c/0x70 mm/slab.c:3696 __kmalloc_reserve.isra.0+0x35/0xd0 net/core/skbuff.c:137 __alloc_skb+0xca/0x4c0 net/core/skbuff.c:205 alloc_skb include/linux/skbuff.h:980 [inline] nlmsg_new include/net/netlink.h:511 [inline] __neigh_notify+0x84/0x150 net/core/neighbour.c:2926 neigh_cleanup_and_release+0x71/0xc0 net/core/neighbour.c:106 neigh_del+0x161/0x1f0 net/core/neighbour.c:141 neigh_forced_gc net/core/neighbour.c:190 [inline] neigh_alloc net/core/neighbour.c:315 [inline] __neigh_create+0xc51/0x1980 net/core/neighbour.c:499 ip6_finish_output2+0xa8e/0x2150 net/ipv6/ip6_output.c:117 ip6_finish_output+0x4d9/0xaf0 net/ipv6/ip6_output.c:154 NF_HOOK_COND include/linux/netfilter.h:239 [inline] ip6_output+0x1c9/0x650 net/ipv6/ip6_output.c:171 dst_output include/net/dst.h:462 [inline] NF_HOOK include/linux/netfilter.h:250 [inline] ndisc_send_skb+0xb56/0x11e0 net/ipv6/ndisc.c:483 ndisc_send_rs+0x125/0x630 net/ipv6/ndisc.c:677 addrconf_rs_timer+0x289/0x5a0 net/ipv6/addrconf.c:3761 call_timer_fn+0x14a/0x650 kernel/time/timer.c:1279 expire_timers kernel/time/timer.c:1318 [inline] __run_timers kernel/time/timer.c:1636 [inline] __run_timers kernel/time/timer.c:1604 [inline] run_timer_softirq+0x52a/0x1390 kernel/time/timer.c:1649 __do_softirq+0x254/0x9bf kernel/softirq.c:288 invoke_softirq kernel/softirq.c:368 [inline] irq_exit+0x15b/0x1a0 kernel/softirq.c:409 exiting_irq arch/x86/include/asm/apic.h:648 [inline] smp_apic_timer_interrupt+0x141/0x5e0 arch/x86/kernel/apic/apic.c:1102 apic_timer_interrupt+0x8f/0xa0 arch/x86/entry/entry_64.S:792 RIP: 0010:rcu_read_lock_sched_held+0x79/0x130 kernel/rcu/update.c:109 RSP: 0018:ffff88803fc577a0 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff10 RAX: 0000000000000001 RBX: ffffffff8813cd20 RCX: 0000000000000002 RDX: 0000000000000000 RSI: ffffffff81971a13 RDI: ffff88803fc4acfc RBP: 0000000000008205 R08: ffff88803fc57a00 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff88804498cb28 R13: 0000000000028b20 R14: dffffc0000000000 R15: ffffffff87d16698 trace_block_touch_buffer include/trace/events/block.h:45 [inline] touch_buffer fs/buffer.c:65 [inline] __find_get_block+0x918/0xbf0 fs/buffer.c:1361 __getblk_gfp+0x37/0x7c0 fs/buffer.c:1379 sb_getblk include/linux/buffer_head.h:325 [inline] ext4_get_branch+0x2d2/0x530 fs/ext4/indirect.c:159 ext4_ind_map_blocks+0x3c5/0x2060 fs/ext4/indirect.c:539 ext4_map_blocks+0x41f/0x1610 fs/ext4/inode.c:570 ext4_get_next_extent+0x139/0x41c fs/ext4/inode.c:6239 ext4_seek_data fs/ext4/file.c:599 [inline] ext4_llseek+0x5ec/0x7c0 fs/ext4/file.c:718 vfs_llseek fs/read_write.c:300 [inline] SYSC_lseek fs/read_write.c:313 [inline] SyS_lseek+0xe4/0x160 fs/read_write.c:304 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x45c889 RSP: 002b:00007f8254616c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000008 RAX: ffffffffffffffda RBX: 00007f82546176d4 RCX: 000000000045c889 RDX: 0000000000000003 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 000000000076bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000717 R14: 00000000004c9e5b R15: 000000000076bf0c