kernel panic: audit: backlog limit exceeded

Status: upstream: reported C repro on 2020/02/24 09:05
Reported-by: syzbot+64e7ca138c88d4d4fd45@syzkaller.appspotmail.com
First crash: 2359d, last: 2269d
Fix bisection the fix commit could be any of (bisect log):
  98db2bf27b9e Linux 4.14.171
  4139fb08c05f Linux 4.14.187
   
▶ ▼ Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream kernel panic: audit: backlog limit exceeded audit 2 syz, C done 6 2360d 2359d 0/29 closed as invalid on 2020/02/27 15:40
linux-4.19 kernel panic: audit: backlog limit exceeded 2 syz, C error 2 1784d 2361d 0/1 upstream: reported C repro on 2020/02/22 16:58
android-54 kernel panic: audit: backlog limit exceeded 2 syz, C 3 2359d 2362d 0/2 closed as invalid on 2020/02/27 15:45
▶ ▼ Last patch testing requests (4)
Created Duration User Patch Repo Result
2022/12/16 08:31 12m retest repro linux-4.14.y report log
2022/12/15 22:31 11m retest repro linux-4.14.y report log
2022/08/29 19:27 11m retest repro linux-4.14.y report log
2022/08/29 18:27 11m retest repro linux-4.14.y report log
▶ ▼ Fix bisection attempts (4)
Created Duration User Patch Repo Result
2020/06/23 17:50 31m (4) bisect fix linux-4.14.y OK (2) job log
2020/05/24 17:27 22m bisect fix linux-4.14.y OK (0) job log log
2020/04/24 17:03 24m bisect fix linux-4.14.y OK (0) job log log
2020/03/25 16:38 24m bisect fix linux-4.14.y OK (0) job log log

Sample crash report:
audit: type=1305 audit(1582562158.609:41): audit_pid=0 old=0 auid=4294967295 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 res=1
audit: audit_backlog=3 > audit_backlog_limit=2
audit: type=1305 audit(1582562158.609:42): audit_rate_limit=4294967295 old=0 auid=4294967295 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 res=1
audit: type=1305 audit(1582562158.609:43): audit_backlog_limit=2 old=64 auid=4294967295 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 res=1
audit: audit_lost=1 audit_rate_limit=4294967295 audit_backlog_limit=2
Kernel panic - not syncing: audit: backlog limit exceeded

CPU: 0 PID: 7283 Comm: syz-executor871 Not tainted 4.14.171-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+0x142/0x197 lib/dump_stack.c:58
 panic+0x1f9/0x42d kernel/panic.c:183
 audit_panic.cold+0x32/0x32 kernel/audit.c:280
 audit_log_lost kernel/audit.c:350 [inline]
 audit_log_lost+0x56/0x100 kernel/audit.c:322
 audit_log_start kernel/audit.c:1734 [inline]
 audit_log_start+0x5e5/0x690 kernel/audit.c:1690
 audit_log+0x85/0x100 kernel/audit.c:2336
 xt_replace_table+0x446/0x620 net/netfilter/x_tables.c:1266
 __do_replace+0x191/0x5c0 net/ipv6/netfilter/ip6_tables.c:1088
 do_replace net/ipv6/netfilter/ip6_tables.c:1161 [inline]
 do_ip6t_set_ctl+0x296/0x3f4 net/ipv6/netfilter/ip6_tables.c:1685
 nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
 nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
 ipv6_setsockopt net/ipv6/ipv6_sockglue.c:930 [inline]
 ipv6_setsockopt+0x105/0x130 net/ipv6/ipv6_sockglue.c:914
 tcp_setsockopt net/ipv4/tcp.c:2826 [inline]
 tcp_setsockopt+0x84/0xd0 net/ipv4/tcp.c:2820
 sock_common_setsockopt+0x94/0xd0 net/core/sock.c:2968
 SYSC_setsockopt net/socket.c:1865 [inline]
 SyS_setsockopt+0x13c/0x210 net/socket.c:1844
 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x44720a
RSP: 002b:00007fffd90c8db8 EFLAGS: 00000202 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000044720a
RDX: 0000000000000040 RSI: 0000000000000029 RDI: 0000000000000003
RBP: 00007fffd90c8ee0 R08: 00000000000003b8 R09: 0000000000004000
R10: 00000000006d7b40 R11: 0000000000000202 R12: 00007fffd90c8de0
R13: 00000000006d9d60 R14: 0000000000000029 R15: 00000000006d7ba0
Kernel Offset: disabled
Rebooting in 86400 seconds..

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/02/24 16:38 linux-4.14.y 98db2bf27b9e 1253d6f0 .config console log report syz C ci2-linux-4-14
2020/02/24 09:04 linux-4.14.y 98db2bf27b9e d801cb02 .config console log report syz C ci2-linux-4-14
* Struck through repros no longer work on HEAD.