bisecting fixing commit since 98db2bf27b9ed2d5ed0b6c9c8a4bfcb127a19796
building syzkaller on 1253d6f07f7f40d2835e0d1e061dcbad49ae28ee
testing commit 98db2bf27b9ed2d5ed0b6c9c8a4bfcb127a19796 with gcc (GCC) 8.1.0
kernel signature: 2b607511f0cfc3573f617c0da61b72e454c74b965316d548250fda485100aa7b
all runs: crashed: kernel panic: audit: backlog limit exceeded
testing current HEAD a41ba30d9df20fe141c92aacbb56b6b077f19716
testing commit a41ba30d9df20fe141c92aacbb56b6b077f19716 with gcc (GCC) 8.1.0
kernel signature: aa6b0266eab6d39f9ed7ac65f026f6397606c8f5515cbd6a7fbda956d546f95f
all runs: crashed: kernel panic: audit: backlog limit exceeded
revisions tested: 2, total time: 22m30.055750901s (build: 15m53.723417417s, test: 6m3.037222092s)
the crash still happens on HEAD
commit msg: Linux 4.14.181
crash: kernel panic: audit: backlog limit exceeded
IPv6: ADDRCONF(NETDEV_CHANGE): veth0_macvtap: link becomes ready
audit: audit_backlog=4 > audit_backlog_limit=2
device veth0_macvtap entered promiscuous mode
audit: audit_backlog=4 > audit_backlog_limit=2
audit: audit_lost=1 audit_rate_limit=4294967295 audit_backlog_limit=2
Kernel panic - not syncing: audit: backlog limit exceeded

audit: audit_lost=2 audit_rate_limit=4294967295 audit_backlog_limit=2
CPU: 0 PID: 6471 Comm: syz-executor.5 Not tainted 4.14.181-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0xf7/0x13b lib/dump_stack.c:58
 panic+0x1b0/0x358 kernel/panic.c:183
 audit_panic.cold.22+0x28/0x28 kernel/audit.c:280
 audit_log_lost+0x42/0xd0 kernel/audit.c:350
 audit_log_start+0x2c5/0x630 kernel/audit.c:1739
 audit_log+0x6a/0xd0 kernel/audit.c:2341
 __dev_set_promiscuity.cold.178+0x26f/0x336 net/core/dev.c:6594
 __dev_set_rx_mode+0x1c8/0x260 net/core/dev.c:6710
 dev_uc_add+0x92/0xa0 net/core/dev_addr_lists.c:496
 macvlan_open+0x30c/0x7a0 drivers/net/macvlan.c:638
 __dev_open+0x178/0x290 net/core/dev.c:1371
 __dev_change_flags+0x3d5/0x550 net/core/dev.c:6797
 dev_change_flags+0x7b/0x150 net/core/dev.c:6863
 do_setlink+0x96f/0x2c50 net/core/rtnetlink.c:2092
 rtnl_newlink+0xe0c/0x1390 net/core/rtnetlink.c:2660
 rtnetlink_rcv_msg+0x34c/0x9e0 net/core/rtnetlink.c:4315
 netlink_rcv_skb+0x133/0x370 net/netlink/af_netlink.c:2433
 rtnetlink_rcv+0x10/0x20 net/core/rtnetlink.c:4327
 netlink_unicast_kernel net/netlink/af_netlink.c:1287 [inline]
 netlink_unicast+0x40b/0x600 net/netlink/af_netlink.c:1313
 netlink_sendmsg+0x730/0xbd0 net/netlink/af_netlink.c:1878
 sock_sendmsg_nosec net/socket.c:646 [inline]
 sock_sendmsg+0xb5/0xf0 net/socket.c:656
 SYSC_sendto+0x1e3/0x2c0 net/socket.c:1763
 SyS_sendto+0x9/0x10 net/socket.c:1731
 do_syscall_64+0x1c7/0x5b0 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x416123
RSP: 002b:00007fffdcd4df08 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 0000000000c82200 RCX: 0000000000416123
RDX: 000000000000002c RSI: 0000000000c82250 RDI: 0000000000000003
RBP: 0000000000000000 R08: 00007fffdcd4df10 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000c82250 R15: 0000000000000003
Shutting down cpus with NMI
Kernel Offset: disabled
Rebooting in 86400 seconds..