bisecting fixing commit since 4fccc2503536a564a4ba31a1d50439854201659f building syzkaller on 2c36e7a75f8689b3da20e1a81a2ee5391f3af6e5 testing commit 4fccc2503536a564a4ba31a1d50439854201659f with gcc (GCC) 8.1.0 kernel signature: 2cbcc9fb903a51a7ceff064090bfe5d5722da6ee6efceb9a5e15c361b88e172b all runs: crashed: kernel panic: audit: backlog limit exceeded testing current HEAD 2c746135a12e3f329171ed168ca0078d468f6d85 testing commit 2c746135a12e3f329171ed168ca0078d468f6d85 with gcc (GCC) 8.1.0 kernel signature: 1d3d4a5761b66316f58be17929ab34c17b5aefb1eb9e3e164c9d4f9892f6fa10 all runs: crashed: kernel panic: audit: backlog limit exceeded revisions tested: 2, total time: 23m3.733149786s (build: 16m46.363959406s, test: 5m28.096436778s) the crash still happens on HEAD commit msg: Linux 4.19.158 crash: kernel panic: audit: backlog limit exceeded audit: audit_lost=1 audit_rate_limit=4294967295 audit_backlog_limit=2 batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! audit: type=1305 audit(1605750904.322:5): audit_backlog_limit=2 old=64 auid=0 ses=8 subj==unconfined res=1 batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3e) already exists on: batadv_slave_1 audit: type=1305 audit(1605750904.322:6): audit_backlog_wait_time=0 old=6000 auid=0 ses=8 subj==unconfined res=1 Kernel panic - not syncing: audit: backlog limit exceeded audit: type=1325 audit(1605750904.382:7): table=filter family=2 entries=4 CPU: 0 PID: 6611 Comm: syz-executor.2 Not tainted 4.19.158-syzkaller #0 batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: IPv6: ADDRCONF(NETDEV_UP): batadv_slave_1: link is not ready __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 batman_adv: batadv0: Interface activated: batadv_slave_1 xt_replace_table+0x555/0x750 net/netfilter/x_tables.c:1418 __do_replace+0x1a9/0x990 net/ipv4/netfilter/ip_tables.c:1070 do_replace net/ipv4/netfilter/ip_tables.c:1143 [inline] do_ipt_set_ctl+0x27e/0x3e5 net/ipv4/netfilter/ip_tables.c:1675 nf_sockopt net/netfilter/nf_sockopt.c:106 [inline] nf_setsockopt+0x5c/0xb0 net/netfilter/nf_sockopt.c:115 ip_setsockopt+0x59/0x70 net/ipv4/ip_sockglue.c:1258 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 audit: type=1325 audit(1605750904.642:8): table=filter family=3 entries=0 __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 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:00007ffedf050fd8 EFLAGS: 00000206 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 00007ffedf051000 RCX: 000000000045efda RDX: 0000000000000040 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 000000000071fe80 R08: 0000000000000370 R09: 0000000000004000 R10: 000000000071e3e0 R11: 0000000000000206 R12: 0000000000000003 R13: 0000000000000000 R14: 0000000000000000 R15: 000000000071e380 Kernel Offset: disabled Rebooting in 86400 seconds..