bisecting fixing commit since 4fccc2503536a564a4ba31a1d50439854201659f building syzkaller on 2c36e7a75f8689b3da20e1a81a2ee5391f3af6e5 testing commit 4fccc2503536a564a4ba31a1d50439854201659f with gcc (GCC) 8.1.0 kernel signature: 7cf5944407f4769ad5c70f1a9ce75944ff5a99eaae0a04efe0f027ffbf8e7231 all runs: crashed: kernel panic: audit: backlog limit exceeded testing current HEAD 3fc898571b974f9a05e4e5c1fe17b18548207091 testing commit 3fc898571b974f9a05e4e5c1fe17b18548207091 with gcc (GCC) 8.1.0 kernel signature: afc3430210b240d809995881c49a7e17d56e6292ca2fb3357858d2f9bba9e07d all runs: crashed: kernel panic: audit: backlog limit exceeded revisions tested: 2, total time: 24m24.792189059s (build: 17m29.673435241s, test: 6m24.334073486s) the crash still happens on HEAD commit msg: Linux 4.19.128 crash: kernel panic: audit: backlog limit exceeded audit: audit_backlog=14 > audit_backlog_limit=2 audit: audit_lost=1 audit_rate_limit=4294967295 audit_backlog_limit=2 audit: type=1325 audit(1592780630.214:13): table=filter family=2 entries=0 audit: audit_backlog=19 > audit_backlog_limit=2 audit: audit_lost=2 audit_rate_limit=4294967295 audit_backlog_limit=2 Kernel panic - not syncing: audit: backlog limit exceeded audit: type=1325 audit(1592780630.214:14): table=nat family=2 entries=0 CPU: 1 PID: 6580 Comm: syz-executor.0 Not tainted 4.19.128-syzkaller #0 audit: type=1325 audit(1592780630.214:15): table=mangle family=2 entries=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+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:1792 audit_log+0x73/0xf0 kernel/audit.c:2383 audit: type=1325 audit(1592780630.214:16): table=raw family=2 entries=0 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:943 tcp_setsockopt+0x6a/0xd0 net/ipv4/tcp.c:3095 sock_common_setsockopt+0x73/0xf0 net/core/sock.c:3049 __sys_setsockopt+0x13e/0x210 net/socket.c:1901 __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: 0033:0x45ef5a Code: 49 89 ca b8 37 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 6a 8b 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 4a 8b fb ff c3 66 0f 1f 84 00 00 00 00 00 RSP: 002b:00007ffda5e35708 EFLAGS: 00000202 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 00007ffda5e35730 RCX: 000000000045ef5a RDX: 0000000000000040 RSI: 0000000000000029 RDI: 0000000000000003 RBP: 000000000071dcc0 R08: 00000000000003b8 R09: 0000000000004000 R10: 000000000071bb60 R11: 0000000000000202 R12: 0000000000000003 R13: 0000000000000000 R14: 0000000000000029 R15: 000000000071bb00 Shutting down cpus with NMI Kernel Offset: disabled Rebooting in 86400 seconds..