INFO: rcu detected stall in __xfrm_decode

[upstream] INFO: rcu detected stall in __xfrm_decode_session
Status: upstream: reported on 2018/02/12 15:22
Reported-by: syzbot+9a24dafd2f9855d33cd3@syzkaller.appspotmail.com
First: 314d, last: 225d

duplicates:
Title	Repro	Count	Last	Reported	Patched	Status
INFO: rcu detected stall in do_softirq		11	307d	316d		closed as dup on 2018/02/14 15:09
INFO: rcu detected stall in _decode_session6		4	168d	278d		closed as dup on 2018/02/12 15:26

Sample crash report:

INFO: rcu_sched self-detected stall on CPU
	0-....: (1 GPs behind) idle=222/1/4611686018427387906 softirq=196202/196203 fqs=31202 
	 (t=125000 jiffies g=95129 c=95128 q=2548)
NMI backtrace for cpu 0
CPU: 0 PID: 6823 Comm: syz-executor6 Not tainted 4.16.0+ #288
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x1a7/0x27d lib/dump_stack.c:53
 nmi_cpu_backtrace+0x1e0/0x220 lib/nmi_backtrace.c:103
 nmi_trigger_cpumask_backtrace+0x123/0x180 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:156 [inline]
 rcu_dump_cpu_stacks+0x186/0x1d3 kernel/rcu/tree.c:1376
 print_cpu_stall kernel/rcu/tree.c:1525 [inline]
 check_cpu_stall.isra.63+0xbb8/0x15b0 kernel/rcu/tree.c:1593
 __rcu_pending kernel/rcu/tree.c:3356 [inline]
 rcu_pending kernel/rcu/tree.c:3401 [inline]
 rcu_check_callbacks+0x21b/0xae0 kernel/rcu/tree.c:2763
 update_process_times+0x30/0x60 kernel/time/timer.c:1636
 tick_sched_handle+0x85/0x160 kernel/time/tick-sched.c:162
 tick_sched_timer+0x42/0x120 kernel/time/tick-sched.c:1170
 __run_hrtimer kernel/time/hrtimer.c:1349 [inline]
 __hrtimer_run_queues+0x39c/0xec0 kernel/time/hrtimer.c:1411
 hrtimer_interrupt+0x2a5/0x6f0 kernel/time/hrtimer.c:1469
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1025 [inline]
 smp_apic_timer_interrupt+0x14a/0x700 arch/x86/kernel/apic/apic.c:1050
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:862
 </IRQ>
RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x50
RSP: 0018:ffff8801aabde340 EFLAGS: 00000287 ORIG_RAX: ffffffffffffff12
RAX: 0000000000000007 RBX: ffff8801c81331c0 RCX: 000000000000fde1
RDX: 0000000000000000 RSI: 0000000000004699 RDI: ffff8801c8133244
RBP: ffff8801aabde3d0 R08: 0000000000000000 R09: ffff8801aabde6a8
R10: 000000000000000b R11: ffffed003557bcdf R12: 000000000000fde1
R13: ffff8801aabde6a8 R14: 00000000000046c8 R15: dffffc0000000000
 __xfrm_decode_session+0x68/0x110 net/xfrm/xfrm_policy.c:2368
 __xfrm_policy_check+0x19e/0x2300 net/xfrm/xfrm_policy.c:2403
 __xfrm_policy_check2 include/net/xfrm.h:1170 [inline]
 xfrm_policy_check include/net/xfrm.h:1175 [inline]
 xfrm6_policy_check include/net/xfrm.h:1185 [inline]
 ip6_input_finish+0x1288/0x17b0 net/ipv6/ip6_input.c:302
 NF_HOOK include/linux/netfilter.h:288 [inline]
 ip6_input+0xdb/0x560 net/ipv6/ip6_input.c:327
 ip6_mc_input+0x3a8/0xb10 net/ipv6/ip6_input.c:404
 dst_input include/net/dst.h:449 [inline]
 ip6_rcv_finish+0x297/0x8c0 net/ipv6/ip6_input.c:71
 NF_HOOK include/linux/netfilter.h:288 [inline]
 ipv6_rcv+0xf45/0x1fc0 net/ipv6/ip6_input.c:208
 __netif_receive_skb_core+0x1a52/0x3480 net/core/dev.c:4562
 __netif_receive_skb+0x2c/0x1b0 net/core/dev.c:4627
 netif_receive_skb_internal+0x10b/0x670 net/core/dev.c:4701
 netif_receive_skb+0xae/0x390 net/core/dev.c:4725
 tun_rx_batched.isra.50+0x5ee/0x870 drivers/net/tun.c:1555
 tun_get_user+0x299b/0x3b50 drivers/net/tun.c:1962
 tun_chr_write_iter+0xb9/0x160 drivers/net/tun.c:1990
 call_write_iter include/linux/fs.h:1782 [inline]
 do_iter_readv_writev+0x55c/0x830 fs/read_write.c:680
 do_iter_write+0x154/0x540 fs/read_write.c:959
 compat_writev+0x225/0x420 fs/read_write.c:1273
 do_compat_writev+0x115/0x220 fs/read_write.c:1294
 C_SYSC_writev fs/read_write.c:1305 [inline]
 compat_SyS_writev+0x26/0x30 fs/read_write.c:1301
 do_syscall_32_irqs_on arch/x86/entry/common.c:330 [inline]
 do_fast_syscall_32+0x3ec/0xf9f arch/x86/entry/common.c:392
 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139
RIP: 0023:0xf7ff2c99
RSP: 002b:00000000f5fee044 EFLAGS: 00000292 ORIG_RAX: 0000000000000092
RAX: ffffffffffffffda RBX: 00000000000000fc RCX: 00000000f5fee094
RDX: 0000000000000001 RSI: 000000000813af00 RDI: 00000000ffffffff
RBP: 00000000f5fee158 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
INFO: rcu_bh detected stalls on CPUs/tasks:
	0-....: (1 GPs behind) idle=222/1/4611686018427387904 softirq=194462/196203 fqs=30995 
	(detected by 1, t=125016 jiffies, g=219, c=218, q=1)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 6823 Comm: syz-executor6 Not tainted 4.16.0+ #288
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__sanitizer_cov_trace_pc+0x38/0x50 kernel/kcov.c:107
RSP: 0018:ffff8801aabde338 EFLAGS: 00000246
RAX: 0000000000040000 RBX: ffff8801c81331c0 RCX: ffffffff861715e5
RDX: 0000000000000002 RSI: ffffc90006a55000 RDI: ffff8801c8133244
RBP: ffff8801aabde338 R08: 0000000000000000 R09: ffff8801aabde6a8
R10: 000000000000000b R11: ffffed003557bcdf R12: 000000000000fde1
R13: ffff8801aabde6a8 R14: 000000000000bde8 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8801db000000(0063) knlGS:00000000f5feeb40
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 00000000f5f6cc20 CR3: 0000000194a19000 CR4: 00000000001426f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 _decode_session6+0x545/0x1380 net/ipv6/xfrm6_policy.c:151
 __xfrm_decode_session+0x68/0x110 net/xfrm/xfrm_policy.c:2368
 __xfrm_policy_check+0x19e/0x2300 net/xfrm/xfrm_policy.c:2403
 __xfrm_policy_check2 include/net/xfrm.h:1170 [inline]
 xfrm_policy_check include/net/xfrm.h:1175 [inline]
 xfrm6_policy_check include/net/xfrm.h:1185 [inline]
 ip6_input_finish+0x1288/0x17b0 net/ipv6/ip6_input.c:302
 NF_HOOK include/linux/netfilter.h:288 [inline]
 ip6_input+0xdb/0x560 net/ipv6/ip6_input.c:327
 ip6_mc_input+0x3a8/0xb10 net/ipv6/ip6_input.c:404
 dst_input include/net/dst.h:449 [inline]
 ip6_rcv_finish+0x297/0x8c0 net/ipv6/ip6_input.c:71
 NF_HOOK include/linux/netfilter.h:288 [inline]
 ipv6_rcv+0xf45/0x1fc0 net/ipv6/ip6_input.c:208
 __netif_receive_skb_core+0x1a52/0x3480 net/core/dev.c:4562
 __netif_receive_skb+0x2c/0x1b0 net/core/dev.c:4627
 netif_receive_skb_internal+0x10b/0x670 net/core/dev.c:4701
 netif_receive_skb+0xae/0x390 net/core/dev.c:4725
 tun_rx_batched.isra.50+0x5ee/0x870 drivers/net/tun.c:1555
 tun_get_user+0x299b/0x3b50 drivers/net/tun.c:1962
 tun_chr_write_iter+0xb9/0x160 drivers/net/tun.c:1990
 call_write_iter include/linux/fs.h:1782 [inline]
 do_iter_readv_writev+0x55c/0x830 fs/read_write.c:680
 do_iter_write+0x154/0x540 fs/read_write.c:959
 compat_writev+0x225/0x420 fs/read_write.c:1273
 do_compat_writev+0x115/0x220 fs/read_write.c:1294
 C_SYSC_writev fs/read_write.c:1305 [inline]
 compat_SyS_writev+0x26/0x30 fs/read_write.c:1301
 do_syscall_32_irqs_on arch/x86/entry/common.c:330 [inline]
 do_fast_syscall_32+0x3ec/0xf9f arch/x86/entry/common.c:392
 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139
RIP: 0023:0xf7ff2c99
RSP: 002b:00000000f5fee044 EFLAGS: 00000292 ORIG_RAX: 0000000000000092
RAX: ffffffffffffffda RBX: 00000000000000fc RCX: 00000000f5fee094
RDX: 0000000000000001 RSI: 000000000813af00 RDI: 00000000ffffffff
RBP: 00000000f5fee158 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
Code: 65 8b 15 8c 77 90 7e 81 e2 00 01 1f 00 48 8b 4d 08 75 2b 8b 90 b8 12 00 00 83 fa 02 75 20 48 8b b0 c0 12 00 00 8b 80 bc 12 00 00 <48> 8b 16 48 83 c2 01 48 39 d0 76 07 48 89 0c d6 48 89 16 5d c3

All crashes (2):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	Maintainers
ci-upstream-kasan-gce-386	2018/04/06 20:56	upstream	f2d28566	4f1152d4	.config	log	report			davem@davemloft.net, herbert@gondor.apana.org.au, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, steffen.klassert@secunet.com
ci-upstream-net-kasan-gce	2018/01/07 13:36	net-next	d0adb51e	19c05fff	.config	log	report			Janakarajan.Natarajan@amd.com, bpetkov@suse.de, gregkh@linuxfoundation.org, hpa@zytor.com, jslaby@suse.cz, linux-kernel@vger.kernel.org, luto@kernel.org, mingo@redhat.com, pombredanne@nexb.com, tglx@linutronix.de, x86@kernel.org