INFO: rcu detected stall in ip_set

INFO: rcu detected stall in ip_set_udel
Status: fixed on 2020/04/15 17:19
Reported-by: syzbot+c27b8d5010f45c666ed1@syzkaller.appspotmail.com
Fix commit: f66ee0410b1c netfilter: ipset: Fix "INFO: rcu detected stall in hash_xxx" reports
First crash: 842d, last: 819d

Cause bisection: introduced by (bisect log) :
commit 23c42a403a9cfdbad6004a556c927be7dd61a8ee
Author: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Date: Sat Oct 27 13:07:40 2018 +0000

netfilter: ipset: Introduction of new commands and protocol version 7

Crash: INFO: task hung in corrupted (log)
Repro: C syz .config

Sample crash report:

rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-....: (10500 ticks this GP) idle=dee/1/0x4000000000000002 softirq=16522/16522 fqs=5250 
	(t=10502 jiffies g=9577 q=109)
NMI backtrace for cpu 1
CPU: 1 PID: 10037 Comm: syz-executor505 Not tainted 5.5.0-rc7-syzkaller #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+0x197/0x210 lib/dump_stack.c:118
 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:2827 [inline]
 rcu_sched_clock_irq.cold+0x509/0xc0d kernel/rcu/tree.c:2271
 update_process_times+0x2d/0x70 kernel/time/timer.c:1726
 tick_sched_handle+0xa2/0x190 kernel/time/tick-sched.c:171
 tick_sched_timer+0x53/0x140 kernel/time/tick-sched.c:1314
 __run_hrtimer kernel/time/hrtimer.c:1517 [inline]
 __hrtimer_run_queues+0x364/0xe40 kernel/time/hrtimer.c:1579
 hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1641
 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:829
 </IRQ>
RIP: 0010:arch_local_irq_disable arch/x86/include/asm/paravirt.h:757 [inline]
RIP: 0010:arch_local_irq_save arch/x86/include/asm/paravirt.h:770 [inline]
RIP: 0010:lock_is_held_type+0xb3/0x320 kernel/locking/lockdep.c:4517
Code: 0f 84 0a 02 00 00 9c 58 0f 1f 44 00 00 48 ba 00 00 00 00 00 fc ff df 48 89 45 c0 48 c7 c0 a0 33 93 89 48 c1 e8 03 80 3c 10 00 <0f> 85 42 02 00 00 48 83 3d 4f 02 39 08 00 0f 84 d4 01 00 00 fa 66
RSP: 0018:ffffc9000204eeb8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: 1ffffffff1326674 RBX: ffff8880a11c6100 RCX: ffffffff86767ccb
RDX: dffffc0000000000 RSI: 00000000ffffffff RDI: ffff88808f906c94
RBP: ffffc9000204ef00 R08: ffff88808f906400 R09: ffffc9000204ef28
R10: fffff52000409de7 R11: ffffc9000204ef3f R12: ffff88808f906400
R13: 00000000bfffffff R14: ffff8880a6bd9a38 R15: ffffc9000204f030
 lock_is_held include/linux/lockdep.h:361 [inline]
 hash_ip4_del+0xa3a/0xce0 net/netfilter/ipset/ip_set_hash_gen.h:847
 hash_ip4_uadt+0x546/0x7a0 net/netfilter/ipset/ip_set_hash_ip.c:151
 call_ad+0x1a0/0x5a0 net/netfilter/ipset/ip_set_core.c:1716
 ip_set_ad.isra.0+0x572/0xb20 net/netfilter/ipset/ip_set_core.c:1804
 ip_set_udel+0x3a/0x50 net/netfilter/ipset/ip_set_core.c:1838
 nfnetlink_rcv_msg+0xcf2/0xfb0 net/netfilter/nfnetlink.c:229
 netlink_rcv_skb+0x177/0x450 net/netlink/af_netlink.c:2477
 nfnetlink_rcv+0x1ba/0x460 net/netfilter/nfnetlink.c:563
 netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline]
 netlink_unicast+0x58c/0x7d0 net/netlink/af_netlink.c:1328
 netlink_sendmsg+0x91c/0xea0 net/netlink/af_netlink.c:1917
 sock_sendmsg_nosec net/socket.c:639 [inline]
 sock_sendmsg+0xd7/0x130 net/socket.c:659
 ____sys_sendmsg+0x753/0x880 net/socket.c:2330
 ___sys_sendmsg+0x100/0x170 net/socket.c:2384
 __sys_sendmsg+0x105/0x1d0 net/socket.c:2417
 __do_sys_sendmsg net/socket.c:2426 [inline]
 __se_sys_sendmsg net/socket.c:2424 [inline]
 __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2424
 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x440509
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 fb 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fff17b4c978 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440509
RDX: 0000000000000000 RSI: 0000000020000080 RDI: 0000000000000004
RBP: 00000000006ca018 R08: 0000000000000018 R09: 00000000004002c8
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000401d90
R13: 0000000000401e20 R14: 0000000000000000 R15: 0000000000000000

Crashes (12):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro
ci-upstream-kasan-gce-root	2020/01/27 01:10	upstream	a45ea48e2bcd	dd56146d	.config	log	report	syz	C
ci-upstream-kasan-gce-root	2020/01/26 05:12	upstream	2821e26f3a0a	f4e7270e	.config	log	report	syz	C
ci-upstream-kasan-gce-selinux-root	2020/01/25 19:12	upstream	d5d359b0ac3f	2e95ab33	.config	log	report	syz	C
ci-upstream-kasan-gce-smack-root	2020/01/24 12:19	upstream	4703d9119972	2e95ab33	.config	log	report	syz	C
ci-upstream-kasan-gce-386	2020/01/25 01:52	upstream	6381b442836e	2e95ab33	.config	log	report	syz	C
ci-upstream-kasan-gce-386	2020/01/24 08:43	upstream	4703d9119972	2e95ab33	.config	log	report	syz	C
ci-upstream-net-this-kasan-gce	2020/01/25 01:43	net	623c8d5c74c6	2e95ab33	.config	log	report	syz	C
ci-upstream-net-kasan-gce	2020/01/25 01:55	net-next	23f4eacdd24a	2e95ab33	.config	log	report	syz	C
ci-upstream-net-kasan-gce	2020/01/24 08:36	net-next	9bbc8be29d66	2e95ab33	.config	log	report	syz	C
ci-upstream-linux-next-kasan-gce-root	2020/02/12 09:28	linux-next	129759899765	a75b198c	.config	log	report	syz	C
ci-upstream-linux-next-kasan-gce-root	2020/02/11 12:23	linux-next	ac431e2d7b1b	084454ae	.config	log	report	syz	C
ci-upstream-net-this-kasan-gce	2020/02/16 09:17	net	2019fc96af22	5d7b90f1	.config	log	report