INFO: rcu detected stall in xfrm_tmpl_resolve

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: 1ffaddd029c8 Linux 4.18-rc8
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=17981ee8400000
kernel config: https://syzkaller.appspot.com/x/.config?x=152cb8ccd35b1f70
dashboard link: https://syzkaller.appspot.com/bug?extid=8cdf703b03bc4cb522e6
compiler: gcc (GCC) 8.0.1 20180413 (experimental)
CC: [da...@davemloft.net her...@gondor.apana.org.au
linux-...@vger.kernel.org net...@vger.kernel.org
steffen....@secunet.com]

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+8cdf70...@syzkaller.appspotmail.com

INFO: rcu_sched detected stalls on CPUs/tasks:
(detected by 0, t=105007 jiffies, g=145333, c=145332, q=844)
All QSes seen, last rcu_sched kthread activity 105014
(4295387170-4295282156), jiffies_till_next_fqs=3, root ->qsmask 0x0
syz-executor7 R running task 25128 19183 4463 0x00000008
Call Trace:
<IRQ>
sched_show_task.cold.84+0x27a/0x301 kernel/sched/core.c:5324
print_other_cpu_stall.cold.77+0x92f/0x9d2 kernel/rcu/tree.c:1441
check_cpu_stall.isra.60+0x721/0xf70 kernel/rcu/tree.c:1559
__rcu_pending kernel/rcu/tree.c:3244 [inline]
rcu_pending kernel/rcu/tree.c:3291 [inline]
rcu_check_callbacks+0x23f/0xcd0 kernel/rcu/tree.c:2646
update_process_times+0x2d/0x70 kernel/time/timer.c:1636
tick_sched_handle+0x9f/0x180 kernel/time/tick-sched.c:164
tick_sched_timer+0x45/0x130 kernel/time/tick-sched.c:1274
__run_hrtimer kernel/time/hrtimer.c:1398 [inline]
__hrtimer_run_queues+0x3eb/0x10c0 kernel/time/hrtimer.c:1460
hrtimer_interrupt+0x2f3/0x750 kernel/time/hrtimer.c:1518
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1028 [inline]
smp_apic_timer_interrupt+0x165/0x730 arch/x86/kernel/apic/apic.c:1053
apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:863
</IRQ>
RIP: 0010:rep_nop arch/x86/include/asm/processor.h:658 [inline]
RIP: 0010:cpu_relax arch/x86/include/asm/processor.h:663 [inline]
RIP: 0010:__read_seqcount_begin include/linux/seqlock.h:115 [inline]
RIP: 0010:raw_read_seqcount_begin include/linux/seqlock.h:148 [inline]
RIP: 0010:read_seqcount_begin include/linux/seqlock.h:165 [inline]
RIP: 0010:xfrm_state_find+0x1c91/0x3550 net/xfrm/xfrm_state.c:950
Code: 39 dd 02 01 e8 cb 3b b7 fb e9 71 e8 ff ff e8 d6 04 d4 fb 0f 0b e8 cf
04 d4 fb 0f 0b 44 89 ad 50 fc ff ff e8 c1 04 d4 fb f3 90 <48> c7 c0 a0 be
8b 88 c6 03 04 31 ff 44 8b 20 45 89 a7 c0 fd ff ff
RSP: 0018:ffff880199b7e808 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: 0000000000040000 RBX: ffffed003336fd41 RCX: ffffc90009736000
RDX: 0000000000040000 RSI: ffffffff85a8138f RDI: 0000000000000005
RBP: ffff880199b7ec70 R08: ffff8801adb64180 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000009
R13: 0000000000000001 R14: 0000000000000000 R15: ffff880199b7ec48
xfrm_tmpl_resolve_one net/xfrm/xfrm_policy.c:1393 [inline]
xfrm_tmpl_resolve+0x383/0xe10 net/xfrm/xfrm_policy.c:1437
xfrm_resolve_and_create_bundle+0x184/0x2c20 net/xfrm/xfrm_policy.c:1832
xfrm_lookup+0x3b3/0x2880 net/xfrm/xfrm_policy.c:2162
xfrm_lookup_route+0x39/0x1f0 net/xfrm/xfrm_policy.c:2282
ip6_dst_lookup_flow+0x1c6/0x270 net/ipv6/ip6_output.c:1085
ip6_sk_dst_lookup_flow+0x5d2/0xac0 net/ipv6/ip6_output.c:1117
udpv6_sendmsg+0x20f9/0x35f0 net/ipv6/udp.c:1357
inet_sendmsg+0x1a1/0x690 net/ipv4/af_inet.c:798
sock_sendmsg_nosec net/socket.c:642 [inline]
sock_sendmsg+0xd5/0x120 net/socket.c:652
__sys_sendto+0x3d7/0x670 net/socket.c:1798
__do_sys_sendto net/socket.c:1810 [inline]
__se_sys_sendto net/socket.c:1806 [inline]
__x64_sys_sendto+0xe1/0x1a0 net/socket.c:1806
do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x456cb9
Code: fd b4 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 b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f0ef604cc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f0ef604d6d4 RCX: 0000000000456cb9
RDX: 0000000000000000 RSI: 0000000020000240 RDI: 0000000000000015
RBP: 0000000000930320 R08: 0000000020000100 R09: 000000000000001c
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004d38a0 R14: 00000000004c852f R15: 0000000000000004
rcu_sched kthread starved for 105963 jiffies! g145333 c145332 f0x2
RCU_GP_WAIT_FQS(3) ->state=0x0 ->cpu=1
RCU grace-period kthread stack dump:
rcu_sched R running task 23568 10 2 0x80000000
Call Trace:
context_switch kernel/sched/core.c:2853 [inline]
__schedule+0x87c/0x1ec0 kernel/sched/core.c:3501
schedule+0xfb/0x450 kernel/sched/core.c:3545
schedule_timeout+0x140/0x260 kernel/time/timer.c:1801
rcu_gp_kthread+0x717/0x1c90 kernel/rcu/tree.c:2179
kthread+0x345/0x410 kernel/kthread.c:246
ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412


---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this bug report. See:
https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with
syzbot.

[Dmitry Vyukov]

superseded by "INFO: rcu detected stall in pppol2tp_sendmsg"
https://syzkaller.appspot.com/bug?extid=adbc5743d1ef43830c76

#syz invalid

> --
> You received this message because you are subscribed to the Google Groups
> "syzkaller-upstream-moderation" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to syzkaller-upstream-m...@googlegroups.com.
> To view this discussion on the web visit
> https://groups.google.com/d/msgid/syzkaller-upstream-moderation/000000000000a60e8b05730fb2ae%40google.com.
> For more options, visit https://groups.google.com/d/optout.