WARNING: proc registration bug in clusterip_tg

WARNING: proc registration bug in clusterip_tg_check (2)
Status: upstream: reported on 2020/05/23 07:29
Reported-by: syzbot+35e9c587ab6de655a1b3@syzkaller.appspotmail.com
First crash: 283d, last: 88d

similar bugs (3):
Kernel	Title	Repro	Count	Last	Reported	Patched	Status
linux-4.19	WARNING: proc registration bug in clusterip_tg_check (2)		2	47d	48d	0/1	upstream: reported on 2021/01/12 15:17
upstream	WARNING: proc registration bug in clusterip_tg_check	C	779	1101d	1119d	4/21	fixed on 2018/02/26 20:04
linux-4.19	WARNING: proc registration bug in clusterip_tg_check		2	298d	340d	0/1	auto-closed as invalid on 2020/09/04 20:53

Sample crash report:

------------[ cut here ]------------
proc_dir_entry 'ipt_CLUSTERIP/172.20.20.187' already registered
WARNING: CPU: 0 PID: 28650 at fs/proc/generic.c:371 proc_register+0x34c/0x700 fs/proc/generic.c:371
Modules linked in:
CPU: 0 PID: 28650 Comm: syz-executor.2 Not tainted 5.10.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:proc_register+0x34c/0x700 fs/proc/generic.c:371
Code: df 48 89 f9 48 c1 e9 03 80 3c 01 00 0f 85 5d 03 00 00 48 8b 44 24 28 48 c7 c7 20 e2 5a 89 48 8b b0 d8 00 00 00 e8 60 52 c8 06 <0f> 0b 48 c7 c7 80 13 4d 8b e8 16 ce 03 07 48 8b 4c 24 38 48 b8 00
RSP: 0018:ffffc90011d273f8 EFLAGS: 00010286
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000040000 RSI: ffffffff8158c855 RDI: fffff520023a4e71
RBP: ffff888022cb15b8 R08: 0000000000000001 R09: ffff8880b9e30627
R10: 0000000000000000 R11: 0000000000000000 R12: ffff888028112358
R13: ffff888028bf5980 R14: dffffc0000000000 R15: 000000000000000d
FS:  00007f0e4078d700(0000) GS:ffff8880b9e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000016b9e60 CR3: 0000000095660000 CR4: 00000000001506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 proc_create_data+0x130/0x190 fs/proc/generic.c:560
 clusterip_config_init net/ipv4/netfilter/ipt_CLUSTERIP.c:281 [inline]
 clusterip_tg_check+0x1771/0x1db0 net/ipv4/netfilter/ipt_CLUSTERIP.c:502
 xt_check_target+0x26c/0x9e0 net/netfilter/x_tables.c:1019
 check_target net/ipv4/netfilter/ip_tables.c:511 [inline]
 find_check_entry.constprop.0+0x7a9/0x9a0 net/ipv4/netfilter/ip_tables.c:553
 translate_table+0xc26/0x16a0 net/ipv4/netfilter/ip_tables.c:717
 do_replace net/ipv4/netfilter/ip_tables.c:1135 [inline]
 do_ipt_set_ctl+0x56e/0xb80 net/ipv4/netfilter/ip_tables.c:1627
 nf_setsockopt+0x83/0xe0 net/netfilter/nf_sockopt.c:101
 ip_setsockopt+0x3c3/0x39f0 net/ipv4/ip_sockglue.c:1435
 udp_setsockopt+0x76/0xc0 net/ipv4/udp.c:2711
 __sys_setsockopt+0x2db/0x610 net/socket.c:2132
 __do_sys_setsockopt net/socket.c:2143 [inline]
 __se_sys_setsockopt net/socket.c:2140 [inline]
 __x64_sys_setsockopt+0xba/0x150 net/socket.c:2140
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45deb9
Code: 0d 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 db b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f0e4078cc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 000000000002f640 RCX: 000000000045deb9
RDX: 0000000000000040 RSI: 0004000000000000 RDI: 0000000000000003
RBP: 000000000119c018 R08: 00000000000002c8 R09: 0000000000000000
R10: 0000000020000000 R11: 0000000000000246 R12: 000000000119bfd4
R13: 00000000016afb7f R14: 00007f0e4078d9c0 R15: 000000000119bfd4

Crashes (7):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	VM info
ci-upstream-kasan-gce	2020/12/03 09:09	upstream	3bb61aa6	8c9190ef	.config	log	report	info
ci-upstream-kasan-gce-selinux-root	2020/09/01 03:05	upstream	f75aef39	d5a3ae1f	.config	log	report
ci-upstream-kasan-gce-root	2020/08/29 19:35	upstream	4d41ead6	d5a3ae1f	.config	log	report
ci-upstream-kasan-gce-selinux-root	2020/07/22 10:42	upstream	4fa640dc	128cd85f	.config	log	report
ci-upstream-kasan-gce-smack-root	2020/05/22 12:22	upstream	d2f8825a	5afa2ddd	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2020/08/15 17:48	linux-next	4993e4fe	424dd8e7	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2020/05/24 12:21	linux-next	c11d28ab	96c92ad3	.config	log	report