syzbot


INFO: rcu detected stall in pppoe_sendmsg

Status: fixed on 2019/10/09 10:54
Subsystems: net
[Documentation on labels]
Reported-by: syzbot+55be5f513bed37fc4367@syzkaller.appspotmail.com
Fix commit: d4d6ec6dac07 sch_hhf: ensure quantum and hhf_non_hh_weight are non-zero
First crash: 1717d, last: 1709d
Discussions (8)
Title Replies (including bot) Last reply
[PATCH 3.16 00/83] 3.16.78-rc1 review 88 (88) 2019/11/21 21:42
[PATCH 4.4 00/56] 4.4.194-stable review 62 (62) 2019/09/20 21:38
[PATCH 4.9 00/74] 4.9.194-stable review 80 (80) 2019/09/20 21:28
[PATCH 4.19 00/50] 4.19.74-stable review 62 (62) 2019/09/20 13:56
[PATCH 5.2 00/85] 5.2.16-stable review 94 (94) 2019/09/19 06:37
[PATCH 4.14 00/45] 4.14.145-stable review 51 (51) 2019/09/19 01:26
[Patch net] sch_hhf: ensure quantum and hhf_non_hh_weight are non-zero 2 (2) 2019/09/10 17:31
INFO: rcu detected stall in pppoe_sendmsg 0 (1) 2019/09/08 07:19
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.19 INFO: rcu detected stall in pppoe_sendmsg 2 1716d 1718d 0/1 auto-closed as invalid on 2020/01/06 02:21

Sample crash report:
rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-....: (1 GPs behind) idle=fa2/1/0x4000000000000002 softirq=66264/66265 fqs=5187 
	(t=10500 jiffies g=108705 q=2407)
NMI backtrace for cpu 1
CPU: 1 PID: 8248 Comm: syz-executor.1 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:1110 [inline]
 smp_apic_timer_interrupt+0x160/0x610 arch/x86/kernel/apic/apic.c:1135
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:830
 </IRQ>
RIP: 0010:__sanitizer_cov_trace_pc+0x4b/0x50 kernel/kcov.c:112
Code: 90 f0 12 00 00 83 fa 02 75 20 48 8b 88 f8 12 00 00 8b 80 f4 12 00 00 48 8b 11 48 83 c2 01 48 39 d0 76 07 48 89 34 d1 48 89 11 <5d> c3 0f 1f 00 65 4c 8b 04 25 40 fe 01 00 65 8b 05 a8 88 8f 7e a9
RSP: 0018:ffff88821972f098 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: 0000000000040000 RBX: ffff8880a1b594f8 RCX: ffffc9000836b000
RDX: 0000000000040000 RSI: ffffffff85c66ad1 RDI: ffff8880a1b59500
RBP: ffff88821972f098 R08: ffff888096c38580 R09: 0000000000000000
R10: fffffbfff134afaf R11: ffff888096c38580 R12: dffffc0000000000
R13: ffff8880a1b59200 R14: ffff8880a1b59598 R15: ffff8880a1b59590
 __read_once_size include/linux/compiler.h:199 [inline]
 list_empty include/linux/list.h:268 [inline]
 hhf_dequeue+0x51/0xa20 net/sched/sch_hhf.c:427
 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
 br_dev_queue_push_xmit+0x3f3/0x5c0 net/bridge/br_forward.c:52
 NF_HOOK include/linux/netfilter.h:305 [inline]
 NF_HOOK include/linux/netfilter.h:299 [inline]
 br_forward_finish+0xfa/0x400 net/bridge/br_forward.c:65
 NF_HOOK include/linux/netfilter.h:305 [inline]
 NF_HOOK include/linux/netfilter.h:299 [inline]
 __br_forward+0x641/0xb00 net/bridge/br_forward.c:109
 br_forward+0x47c/0x500 net/bridge/br_forward.c:158
 br_dev_xmit+0xbf0/0x15a0 net/bridge/br_device.c:102
 __netdev_start_xmit include/linux/netdevice.h:4406 [inline]
 netdev_start_xmit include/linux/netdevice.h:4420 [inline]
 xmit_one net/core/dev.c:3280 [inline]
 dev_hard_start_xmit+0x1a3/0x9c0 net/core/dev.c:3296
 __dev_queue_xmit+0x2b15/0x3650 net/core/dev.c:3869
 dev_queue_xmit+0x18/0x20 net/core/dev.c:3902
 pppoe_sendmsg+0x661/0x7f0 drivers/net/ppp/pppoe.c:899
 sock_sendmsg_nosec net/socket.c:637 [inline]
 sock_sendmsg+0xd7/0x130 net/socket.c:657
 ___sys_sendmsg+0x3e2/0x920 net/socket.c:2311
 __sys_sendmmsg+0x1bf/0x4d0 net/socket.c:2413
 __do_sys_sendmmsg net/socket.c:2442 [inline]
 __se_sys_sendmmsg net/socket.c:2439 [inline]
 __x64_sys_sendmmsg+0x9d/0x100 net/socket.c:2439
 do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4598e9
Code: fd b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fa79f96fc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00000000004598e9
RDX: 000000000000033b RSI: 000000002000d180 RDI: 0000000000000006
RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fa79f9706d4
R13: 00000000004c70a7 R14: 00000000004dc768 R15: 00000000ffffffff

Crashes (7):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/09/14 23:01 upstream a7f89616b737 32d59357 .config console log report ci-upstream-kasan-gce
2019/09/07 07:25 upstream 1e3778cb223e a60cb4cd .config console log report ci-upstream-kasan-gce-root
2019/09/13 03:08 upstream 505a8ec7e11a 40fa42bc .config console log report ci-upstream-kasan-gce-386
2019/09/08 10:14 net-old 28abe5796252 a60cb4cd .config console log report ci-upstream-net-this-kasan-gce
2019/09/09 23:24 net-next-old 6703a605b5ab a60cb4cd .config console log report ci-upstream-net-kasan-gce
2019/09/09 20:27 net-next-old 6703a605b5ab a60cb4cd .config console log report ci-upstream-net-kasan-gce
2019/09/07 01:08 net-next-old 1e46c09ec100 a60cb4cd .config console log report ci-upstream-net-kasan-gce
* Struck through repros no longer work on HEAD.