bisecting fixing commit since 4fccc2503536a564a4ba31a1d50439854201659f building syzkaller on 2c36e7a75f8689b3da20e1a81a2ee5391f3af6e5 testing commit 4fccc2503536a564a4ba31a1d50439854201659f with gcc (GCC) 8.1.0 kernel signature: efe7fb4149dfb48ced346f19af88eef425d5806bd4564ee84f33ac5e7c4f2e43 all runs: crashed: kernel panic: audit: backlog limit exceeded testing current HEAD ad326970d25cc85128cd22d62398751ad072efff testing commit ad326970d25cc85128cd22d62398751ad072efff with gcc (GCC) 8.1.0 kernel signature: 71f72adeadf142b8989981cc1a09d054b3d1b47dea3ed56a13a5e729f0e3b757 all runs: crashed: kernel panic: audit: backlog limit exceeded revisions tested: 2, total time: 25m29.404415603s (build: 18m30.96046116s, test: 5m58.020579308s) the crash still happens on HEAD commit msg: Linux 4.19.152 crash: kernel panic: audit: backlog limit exceeded audit: audit_backlog=4 > audit_backlog_limit=2 audit: audit_lost=1 audit_rate_limit=4294967295 audit_backlog_limit=2 audit: type=1305 audit(1603156453.687:12): audit_pid=0 old=0 auid=0 ses=8 subj=system_u:system_r:kernel_t:s0 res=1 audit: type=1305 audit(1603156453.687:13): audit_rate_limit=4294967295 old=0 auid=0 ses=8 subj=system_u:system_r:kernel_t:s0 res=1 Kernel panic - not syncing: audit: backlog limit exceeded CPU: 1 PID: 6570 Comm: syz-executor.0 Not tainted 4.19.152-syzkaller #0 audit: type=1305 audit(1603156453.687:14): audit_backlog_limit=2 old=64 auid=0 ses=8 subj=system_u:system_r:kernel_t:s0 res=1 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 audit: type=1305 audit(1603156453.687:15): audit_backlog_wait_time=0 old=6000 auid=0 ses=8 subj=system_u:system_r:kernel_t:s0 res=1 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+0x1a9/0x990 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:3095 sock_common_setsockopt+0x73/0xf0 net/core/sock.c:3072 __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: 0033:0x45efda 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:00007ffdc2fd3c48 EFLAGS: 00000206 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 00007ffdc2fd3c70 RCX: 000000000045efda RDX: 0000000000000040 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 000000000071fe80 R08: 00000000000002d8 R09: 0000000000004000 R10: 000000000071dd20 R11: 0000000000000206 R12: 0000000000000003 R13: 0000000000000000 R14: 0000000000000000 R15: 000000000071dcc0 Kernel Offset: disabled Rebooting in 86400 seconds..