kernel panic: audit: backlog limit exceeded

kernel panic: audit: backlog limit exceeded
Status: closed as invalid on 2020/02/27 15:45
Reported-by: syzbot+ef9efc0b646a3369800c@syzkaller.appspotmail.com
First crash: 653d, last: 651d

similar bugs (3):
Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	kernel panic: audit: backlog limit exceeded	C	done		6	652d	651d	0/22	closed as invalid on 2020/02/27 15:40
linux-4.19	kernel panic: audit: backlog limit exceeded	C		error	2	76d	653d	0/1	upstream: reported C repro on 2020/02/22 16:58
linux-4.14	kernel panic: audit: backlog limit exceeded	C		inconclusive	2	561d	651d	0/1	upstream: reported C repro on 2020/02/24 09:05

Sample crash report:

audit: audit_backlog=34 > audit_backlog_limit=2
audit: audit_lost=2 audit_rate_limit=4294967295 audit_backlog_limit=2
Kernel panic - not syncing: audit: backlog limit exceeded
CPU: 1 PID: 1884 Comm: syz-executor810 Not tainted 5.4.21-syzkaller-00756-ge12432318607 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1b0/0x228 lib/dump_stack.c:118
 panic+0x26c/0x719 kernel/panic.c:221
 audit_panic kernel/audit.c:306 [inline]
 audit_log_lost+0x1d7/0x1e0 kernel/audit.c:376
 audit_log_start+0x55b/0x9a0 kernel/audit.c:1795
 audit_log+0x99/0x130 kernel/audit.c:2343
 xt_replace_table+0x61b/0x7a0 net/netfilter/x_tables.c:1413
 xt_register_table+0x238/0x590 net/netfilter/x_tables.c:1452
 arpt_register_table+0x161/0x6d0 net/ipv4/netfilter/arp_tables.c:1559
 arptable_filter_table_init+0x7b/0xa0 net/ipv4/netfilter/arptable_filter.c:53
 xt_find_table_lock+0x251/0x3a0 net/netfilter/x_tables.c:1223
 xt_request_find_table_lock+0x27/0xc0 net/netfilter/x_tables.c:1253
 get_info+0x1c3/0x530 net/ipv4/netfilter/arp_tables.c:808
 do_arpt_get_ctl+0x151/0x9a0 net/ipv4/netfilter/arp_tables.c:1485
 nf_sockopt net/netfilter/nf_sockopt.c:104 [inline]
 nf_getsockopt+0x28e/0x2b0 net/netfilter/nf_sockopt.c:122
 ip_getsockopt+0x13c/0x230 net/ipv4/ip_sockglue.c:1576
 tcp_getsockopt+0xbe/0xd0 net/ipv4/tcp.c:3691
 sock_common_getsockopt+0x99/0xb0 net/core/sock.c:3110
 __sys_getsockopt+0x1f4/0x360 net/socket.c:2130
 __do_sys_getsockopt net/socket.c:2145 [inline]
 __se_sys_getsockopt net/socket.c:2142 [inline]
 __x64_sys_getsockopt+0xbf/0xd0 net/socket.c:2142
 do_syscall_64+0xc0/0x100 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x44494a
Code: b8 10 01 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 8d df fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 49 89 ca b8 37 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 6a df fb ff c3 66 0f 1f 84 00 00 00 00 00
RSP: 002b:00007ffdd17792c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000037
RAX: ffffffffffffffda RBX: 00000000004a31c9 RCX: 000000000044494a
RDX: 0000000000000060 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 0000000000000003 R08: 00007ffdd17792dc R09: 0000000000000000
R10: 00000000006cd448 R11: 0000000000000246 R12: 00000000006ccdc8
R13: 0000000000402dd0 R14: 0000000000000000 R15: 0000000000000000
Shutting down cpus with NMI
Kernel Offset: disabled
Rebooting in 86400 seconds..

Crashes (3):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro
ci2-android-5-4-kasan	2020/02/22 07:11	https://android.googlesource.com/kernel/common android-5.4	e12432318607	2ffa6679	.config	log	report	syz	C
ci2-android-5-4-kasan	2020/02/22 03:05	https://android.googlesource.com/kernel/common android-5.4	e12432318607	2ffa6679	.config	log	report	syz	C
ci2-android-5-4-kasan	2020/02/24 14:51	https://android.googlesource.com/kernel/common android-5.4	e12432318607	1253d6f0	.config	log	report