syzbot


INFO: rcu detected stall in mld_dad_timer_expire

Status: fixed on 2019/10/09 10:54
Reported-by: syzbot+@syzkaller.appspotmail.com
Fix commit: d4d6ec6dac07 sch_hhf: ensure quantum and hhf_non_hh_weight are non-zero
First crash: 1021d, last: 1019d
similar bugs (3):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.14 INFO: rcu detected stall in mld_dad_timer_expire C done 1 1015d 1015d 1/1 fixed on 2019/12/09 13:28
linux-4.19 INFO: rcu detected stall in mld_dad_timer_expire 1 664d 664d 0/1 auto-closed as invalid on 2020/12/29 00:26
upstream INFO: rcu detected stall in mld_dad_timer_expire (2) 2 939d 939d 0/22 closed as invalid on 2019/11/29 14:24

Sample crash report:
rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-....: (1 GPs behind) idle=34e/1/0x4000000000000004 softirq=96645/96646 fqs=5231 
	(t=10500 jiffies g=160309 q=489)
NMI backtrace for cpu 1
CPU: 1 PID: 24742 Comm: syz-executor.5 Not tainted 5.3.0-rc8 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x172/0x1f0 lib/dump_stack.c:113
 nmi_cpu_backtrace.cold+0x70/0xb2 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x23b/0x28b 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:164 [inline]
 rcu_dump_cpu_stacks+0x183/0x1cf kernel/rcu/tree_stall.h:254
 print_cpu_stall kernel/rcu/tree_stall.h:455 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:529 [inline]
 rcu_pending kernel/rcu/tree.c:2736 [inline]
 rcu_sched_clock_irq.cold+0x4dd/0xc13 kernel/rcu/tree.c:2183
 update_process_times+0x32/0x80 kernel/time/timer.c:1639
 tick_sched_handle+0xa2/0x190 kernel/time/tick-sched.c:167
 tick_sched_timer+0x53/0x140 kernel/time/tick-sched.c:1296
 __run_hrtimer kernel/time/hrtimer.c:1389 [inline]
 __hrtimer_run_queues+0x364/0xe40 kernel/time/hrtimer.c:1451
 hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1509
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1106 [inline]
 smp_apic_timer_interrupt+0x160/0x610 arch/x86/kernel/apic/apic.c:1131
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:830
RIP: 0010:__list_del_entry_valid+0x7e/0xf5 lib/list_debug.c:51
Code: de 4d 8b 2e 49 39 c5 0f 84 e1 00 00 00 48 b8 22 01 00 00 00 00 ad de 49 39 c4 0f 84 e2 00 00 00 48 b8 00 00 00 00 00 fc ff df <4c> 89 e2 48 c1 ea 03 80 3c 02 00 75 53 49 8b 14 24 4c 39 f2 0f 85
RSP: 0018:ffff8880ae9095a0 EFLAGS: 00000216 ORIG_RAX: ffffffffffffff13
RAX: dffffc0000000000 RBX: ffff8880915850b8 RCX: ffffffff85c65b39
RDX: 1ffff110122b0a17 RSI: ffffffff85c66006 RDI: ffff8880915850c0
RBP: ffff8880ae9095b8 R08: ffff888089ea0480 R09: 0000000000000000
R10: fffffbfff134afaf R11: ffff888089ea0480 R12: ffff888091585150
R13: ffff888091585150 R14: ffff8880915850b8 R15: 0000000000000000
 __list_del_entry include/linux/list.h:131 [inline]
 list_move_tail include/linux/list.h:213 [inline]
 hhf_dequeue+0x5c5/0xa20 net/sched/sch_hhf.c:439
 dequeue_skb net/sched/sch_generic.c:258 [inline]
 qdisc_restart net/sched/sch_generic.c:361 [inline]
 __qdisc_run+0x1e7/0x19d0 net/sched/sch_generic.c:379
 __dev_xmit_skb net/core/dev.c:3533 [inline]
 __dev_queue_xmit+0x16f1/0x3650 net/core/dev.c:3838
 dev_queue_xmit+0x18/0x20 net/core/dev.c:3902
 neigh_hh_output include/net/neighbour.h:500 [inline]
 neigh_output include/net/neighbour.h:509 [inline]
 ip6_finish_output2+0xf58/0x2520 net/ipv6/ip6_output.c:116
 __ip6_finish_output+0x444/0xa50 net/ipv6/ip6_output.c:142
 ip6_finish_output+0x38/0x1f0 net/ipv6/ip6_output.c:152
 NF_HOOK_COND include/linux/netfilter.h:294 [inline]
 ip6_output+0x235/0x7c0 net/ipv6/ip6_output.c:175
 dst_output include/net/dst.h:436 [inline]
 NF_HOOK include/linux/netfilter.h:305 [inline]
 NF_HOOK include/linux/netfilter.h:299 [inline]
 mld_sendpack+0x9c7/0xea0 net/ipv6/mcast.c:1682
 mld_send_initial_cr.part.0+0x114/0x160 net/ipv6/mcast.c:2099
 mld_send_initial_cr net/ipv6/mcast.c:2083 [inline]
 mld_dad_timer_expire+0x42/0x1c0 net/ipv6/mcast.c:2118
 call_timer_fn+0x1ac/0x780 kernel/time/timer.c:1322
 expire_timers kernel/time/timer.c:1366 [inline]
 __run_timers kernel/time/timer.c:1685 [inline]
 __run_timers kernel/time/timer.c:1653 [inline]
 run_timer_softirq+0x697/0x17a0 kernel/time/timer.c:1698
 __do_softirq+0x262/0x98c kernel/softirq.c:292
 invoke_softirq kernel/softirq.c:373 [inline]
 irq_exit+0x19b/0x1e0 kernel/softirq.c:413
 exiting_irq arch/x86/include/asm/apic.h:537 [inline]
 smp_apic_timer_interrupt+0x1a3/0x610 arch/x86/kernel/apic/apic.c:1133
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:830
 </IRQ>
RIP: 0010:arch_stack_walk+0xb/0xf0 arch/x86/kernel/stacktrace.c:17
Code: ee ee eb d0 e6 81 eb f0 e6 87 eb ec e6 83 eb e8 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 48 89 e5 41 56 49 89 d6 41 55 <49> 89 cd 41 54 49 89 f4 53 48 89 fb 48 83 ec 68 65 48 8b 04 25 28
RSP: 0018:ffff88809471f5f8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: ffff888089ea0480 RBX: ffffed10128e3ec3 RCX: 0000000000000000
RDX: ffff888089ea0480 RSI: ffff88809471f638 RDI: ffffffff81616ae0
RBP: ffff88809471f608 R08: ffff888089ea0480 R09: ffffed101221e626
R10: fffffbfff134afaf R11: ffffffff89a57d7f R12: 0000000000000001
R13: 0000000000000040 R14: ffff888089ea0480 R15: ffff88808e019a80
 stack_trace_save+0xac/0xe0 kernel/stacktrace.c:123
 save_stack+0x23/0x90 mm/kasan/common.c:69
 set_track mm/kasan/common.c:77 [inline]
 __kasan_kmalloc mm/kasan/common.c:493 [inline]
 __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:466
 kasan_slab_alloc+0xf/0x20 mm/kasan/common.c:501
 slab_post_alloc_hook mm/slab.h:520 [inline]
 slab_alloc mm/slab.c:3319 [inline]
 kmem_cache_alloc+0x121/0x710 mm/slab.c:3483
 anon_vma_chain_alloc mm/rmap.c:129 [inline]
 anon_vma_clone+0xde/0x480 mm/rmap.c:269
 anon_vma_fork+0x8f/0x4a0 mm/rmap.c:332
 dup_mmap kernel/fork.c:547 [inline]
 dup_mm+0xa47/0x1430 kernel/fork.c:1346
 copy_mm kernel/fork.c:1402 [inline]
 copy_process+0x28b7/0x6b00 kernel/fork.c:2017
 _do_fork+0x146/0xfa0 kernel/fork.c:2369
 __do_sys_clone kernel/fork.c:2524 [inline]
 __se_sys_clone kernel/fork.c:2505 [inline]
 __x64_sys_clone+0x18d/0x250 kernel/fork.c:2505
 do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457eba
Code: f7 d8 64 89 04 25 d4 02 00 00 64 4c 8b 0c 25 10 00 00 00 31 d2 4d 8d 91 d0 02 00 00 31 f6 bf 11 00 20 01 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 0f 87 f5 00 00 00 85 c0 41 89 c5 0f 85 fc 00 00
RSP: 002b:00007ffe5d440260 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007ffe5d440260 RCX: 0000000000457eba
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 00007ffe5d4402a0 R08: 0000000000000001 R09: 0000555556b57940
R10: 0000555556b57c10 R11: 0000000000000246 R12: 0000000000000001
R13: 0000000000000000 R14: 0000000000000000 R15: 00007ffe5d4402f0

Crashes (3):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-kasan-gce-root 2019/09/09 06:12 upstream f74c2bb98776 a60cb4cd .config log report
ci-upstream-net-kasan-gce 2019/09/11 06:02 net-next 074be7fd99a2 a60cb4cd .config log report
ci-upstream-net-kasan-gce 2019/09/09 08:51 net-next 6703a605b5ab a60cb4cd .config log report