syzbot


INFO: rcu detected stall in netlink_sendmsg

Status: fixed on 2019/12/10 03:52
Reported-by: syzbot+f17e001b1afb90d01cb0@syzkaller.appspotmail.com
Fix commit: a9e91767b921 sch_hhf: ensure quantum and hhf_non_hh_weight are non-zero
First crash: 1182d, last: 1177d

Fix bisection: fixed by (bisect log) :
commit a9e91767b921ee196ab693fa13a81b278f53ddac
Author: Cong Wang <xiyou.wangcong@gmail.com>
Date: Sun Sep 8 20:40:51 2019 +0000

  sch_hhf: ensure quantum and hhf_non_hh_weight are non-zero

similar bugs (4):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in netlink_sendmsg (2) C done 11 1179d 1185d 14/24 fixed on 2019/10/09 10:54
upstream INFO: rcu detected stall in netlink_sendmsg (3) C done 6 1029d 1083d 16/24 fixed on 2020/02/18 14:31
upstream INFO: rcu detected stall in netlink_sendmsg syz 83 1388d 1444d 12/24 fixed on 2019/03/06 07:43
upstream INFO: rcu detected stall in netlink_sendmsg (4) C done error 37 7d14h 980d 0/24 upstream: reported C repro on 2020/03/31 17:43

Sample crash report:
IPv6: ADDRCONF(NETDEV_UP): hsr0: link is not ready
IPv6: ADDRCONF(NETDEV_CHANGE): hsr0: link becomes ready
IPv6: ADDRCONF(NETDEV_UP): vxcan1: link is not ready
8021q: adding VLAN 0 to HW filter on device batadv0
rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-....: (1 GPs behind) idle=7b6/1/0x4000000000000002 softirq=11200/11201 fqs=5250 
rcu: 	 (t=10502 jiffies g=5317 q=197)
NMI backtrace for cpu 1
CPU: 1 PID: 7658 Comm: syz-executor744 Not tainted 4.19.73 #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+0x63/0xa4 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x1b0/0x1f8 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+0x189/0x1d5 kernel/rcu/tree.c:1340
 print_cpu_stall kernel/rcu/tree.c:1478 [inline]
 check_cpu_stall kernel/rcu/tree.c:1550 [inline]
 __rcu_pending kernel/rcu/tree.c:3293 [inline]
 rcu_pending kernel/rcu/tree.c:3336 [inline]
 rcu_check_callbacks.cold+0x5e3/0xd90 kernel/rcu/tree.c:2682
 update_process_times+0x32/0x80 kernel/time/timer.c:1636
 tick_sched_handle+0xa2/0x190 kernel/time/tick-sched.c:164
 tick_sched_timer+0x47/0x130 kernel/time/tick-sched.c:1274
 __run_hrtimer kernel/time/hrtimer.c:1398 [inline]
 __hrtimer_run_queues+0x33b/0xdc0 kernel/time/hrtimer.c:1460
 hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1518
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1067 [inline]
 smp_apic_timer_interrupt+0x111/0x550 arch/x86/kernel/apic/apic.c:1092
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:893
 </IRQ>
RIP: 0010:list_add_tail include/linux/list.h:93 [inline]
RIP: 0010:list_move_tail include/linux/list.h:183 [inline]
RIP: 0010:hhf_dequeue+0x636/0xa00 net/sched/sch_hhf.c:438
Code: 48 c1 ea 03 42 80 3c 22 00 0f 85 7c 03 00 00 4d 89 3e e8 4d a4 dc fb 4d 8d b5 58 03 00 00 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 <0f> 85 4e 03 00 00 4d 8b bd 58 03 00 00 48 89 df 48 8b 55 c8 4c 89
RSP: 0018:ffff8880a098f358 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: 1ffff11010cfdeb3 RBX: ffff8880867ef4f8 RCX: ffffffff858ebde6
RDX: 0000000000000000 RSI: ffffffff858ebe53 RDI: ffff8880867ef598
RBP: ffff8880a098f3a8 R08: ffff88809de60580 R09: 0000000000000003
R10: ffff88809de60e78 R11: 000000000e8614fd R12: dffffc0000000000
R13: ffff8880867ef240 R14: ffff8880867ef598 R15: ffff8880867ef590
 dequeue_skb net/sched/sch_generic.c:277 [inline]
 qdisc_restart net/sched/sch_generic.c:380 [inline]
 __qdisc_run+0x1e7/0x1960 net/sched/sch_generic.c:398
 __dev_xmit_skb net/core/dev.c:3501 [inline]
 __dev_queue_xmit+0x165c/0x2fe0 net/core/dev.c:3811
 dev_queue_xmit+0x18/0x20 net/core/dev.c:3876
 __netlink_deliver_tap_skb net/netlink/af_netlink.c:303 [inline]
 __netlink_deliver_tap net/netlink/af_netlink.c:321 [inline]
 netlink_deliver_tap+0x910/0xc20 net/netlink/af_netlink.c:334
 __netlink_sendskb+0x68/0xc0 net/netlink/af_netlink.c:1261
 netlink_sendskb net/netlink/af_netlink.c:1270 [inline]
 netlink_unicast+0x616/0x720 net/netlink/af_netlink.c:1358
 netlink_ack+0x645/0xb30 net/netlink/af_netlink.c:2424
 netlink_rcv_skb+0x382/0x460 net/netlink/af_netlink.c:2460
 rtnetlink_rcv+0x1d/0x30 net/core/rtnetlink.c:4765
 netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline]
 netlink_unicast+0x537/0x720 net/netlink/af_netlink.c:1343
 netlink_sendmsg+0x8ae/0xd70 net/netlink/af_netlink.c:1908
 sock_sendmsg_nosec net/socket.c:622 [inline]
 sock_sendmsg+0xd7/0x130 net/socket.c:632
 ___sys_sendmsg+0x803/0x920 net/socket.c:2115
 __sys_sendmsg+0x105/0x1d0 net/socket.c:2153
 __do_sys_sendmsg net/socket.c:2162 [inline]
 __se_sys_sendmsg net/socket.c:2160 [inline]
 __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2160
 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x441b19
Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 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 7b 10 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffe6764dd78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000441b19
RDX: 0000000000000000 RSI: 0000000020000240 RDI: 0000000000000003
RBP: 00007ffe6764dd90 R08: 0000000001bbbbbb R09: 0000000001bbbbbb
R10: 0000000001bbbbbb R11: 0000000000000246 R12: 0000000000000000
R13: 00000000004030b0 R14: 0000000000000000 R15: 0000000000000000

Crashes (3):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-linux-4-19 2019/09/16 22:58 linux-4.19.y db2d0b7c1dde 51ca0454 .config log report syz C
ci2-linux-4-19 2019/09/15 20:18 linux-4.19.y ee809c7e0895 32d59357 .config log report syz C
ci2-linux-4-19 2019/09/11 23:39 linux-4.19.y ee809c7e0895 f4e53c10 .config log report
* Struck through repros no longer work on HEAD.