bisecting fixing commit since 4fccc2503536a564a4ba31a1d50439854201659f
building syzkaller on 2c36e7a75f8689b3da20e1a81a2ee5391f3af6e5
testing commit 4fccc2503536a564a4ba31a1d50439854201659f with gcc (GCC) 8.1.0
kernel signature: 8289a1d2e51d372a80dd2cf32be3543566229344b61c58eb9d619177e375c72b
all runs: crashed: kernel panic: audit: backlog limit exceeded
testing current HEAD 13d2ce42de8cb98ff952f8de6307f896203854c2
testing commit 13d2ce42de8cb98ff952f8de6307f896203854c2 with gcc (GCC) 8.1.0
kernel signature: 24d5570f16de7802f43ad7ca500561d3e545dd9a953c4076092b1c36165a1f70
all runs: crashed: kernel panic: audit: backlog limit exceeded
revisions tested: 2, total time: 27m2.253285731s (build: 21m2.247887308s, test: 5m9.611830908s)
the crash still happens on HEAD
commit msg: Linux 4.19.163
crash: kernel panic: audit: backlog limit exceeded
audit: audit_backlog=17 > audit_backlog_limit=2
audit: audit_lost=1 audit_rate_limit=4294967295 audit_backlog_limit=2
IPv6: ADDRCONF(NETDEV_UP): batadv_slave_1: link is not ready
audit: type=1305 audit(1608354374.043:7): audit_enabled=1 old=1 auid=0 ses=8 subj==unconfined res=1
batman_adv: batadv0: Interface activated: batadv_slave_1
Kernel panic - not syncing: audit: backlog limit exceeded

audit: type=1305 audit(1608354374.043:8): audit_failure=2 old=2 auid=0 ses=8 subj==unconfined res=1
CPU: 0 PID: 5942 Comm: syz-executor.1 Not tainted 4.19.163-syzkaller #0
audit: type=1305 audit(1608354374.043:9): audit_pid=0 old=0 auid=0 ses=8 subj==unconfined res=1
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+0x123/0x177 lib/dump_stack.c:118
 panic+0x1cd/0x375 kernel/panic.c:186
 audit_panic.cold.22+0x28/0x28 kernel/audit.c:320
 audit_log_lost+0x57/0x120 kernel/audit.c:390
 audit_log_start+0x2e7/0x680 kernel/audit.c:1800
 audit_log+0x73/0xf0 kernel/audit.c:2391
 xt_replace_table+0x555/0x750 net/netfilter/x_tables.c:1418
 __do_replace+0x1a9/0x9b0 net/ipv6/netfilter/ip6_tables.c:1087
 do_replace net/ipv6/netfilter/ip6_tables.c:1160 [inline]
 do_ip6t_set_ctl+0x27e/0x3eb net/ipv6/netfilter/ip6_tables.c:1684
 nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
 nf_setsockopt+0x5c/0xb0 net/netfilter/nf_sockopt.c:115
 ipv6_setsockopt+0x95/0xf0 net/ipv6/ipv6_sockglue.c:945
 tcp_setsockopt+0x6a/0xd0 net/ipv4/tcp.c:3097
 sock_common_setsockopt+0x73/0xf0 net/core/sock.c:3072
 __sys_setsockopt+0x13e/0x210 net/socket.c:1901
device veth0_macvtap entered promiscuous mode
 __do_sys_setsockopt net/socket.c:1912 [inline]
 __se_sys_setsockopt net/socket.c:1909 [inline]
 __x64_sys_setsockopt+0xb9/0x150 net/socket.c:1909
IPv6: ADDRCONF(NETDEV_UP): macvtap0: link is not ready
 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45efda
Code: 49 89 ca b8 37 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 ea 8a fb ff c3 66 0f 1f 84 00 00 00 00 00 49 89 ca b8 36 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 ca 8a fb ff c3 66 0f 1f 84 00 00 00 00 00
RSP: 002b:00007ffc7b30c3c8 EFLAGS: 00000202 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007ffc7b30c3f0 RCX: 000000000045efda
RDX: 0000000000000040 RSI: 0000000000000029 RDI: 0000000000000003
RBP: 000000000071dcc0 R08: 00000000000003b8 R09: 0000000000004000
R10: 000000000071bb60 R11: 0000000000000202 R12: 0000000000000003
R13: 0000000000000000 R14: 0000000000000029 R15: 000000000071bb00
Kernel Offset: disabled
Rebooting in 86400 seconds..