syzbot


kernel panic: audit: backlog limit exceeded

Status: upstream: reported C repro on 2020/02/22 16:58
Reported-by: syzbot+6ad55874f4c0198b4862@syzkaller.appspotmail.com
First crash: 952d, last: 375d

Fix bisection: failed (bisect log)
similar bugs (3):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream kernel panic: audit: backlog limit exceeded C done 6 952d 951d 0/24 closed as invalid on 2020/02/27 15:40
linux-4.14 kernel panic: audit: backlog limit exceeded C inconclusive 2 860d 951d 0/1 upstream: reported C repro on 2020/02/24 09:05
android-54 kernel panic: audit: backlog limit exceeded C 3 951d 953d 0/2 closed as invalid on 2020/02/27 15:45

Sample crash report:
audit: type=1305 audit(1582406160.622:41): 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(1582406160.622:42): audit_rate_limit=4294967295 old=0 auid=4294967295 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 res=1
audit: audit_lost=1 audit_rate_limit=4294967295 audit_backlog_limit=2
audit: type=1305 audit(1582406160.622:43): audit_backlog_limit=2 old=64 auid=4294967295 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 res=1
Kernel panic - not syncing: audit: backlog limit exceeded

CPU: 1 PID: 8178 Comm: syz-executor876 Not tainted 4.19.105-syzkaller #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+0x197/0x210 lib/dump_stack.c:118
 panic+0x26a/0x50e kernel/panic.c:186
 audit_panic.cold+0x32/0x32 kernel/audit.c:320
 audit_log_lost kernel/audit.c:390 [inline]
 audit_log_lost+0x8b/0x180 kernel/audit.c:362
 audit_log_start kernel/audit.c:1787 [inline]
 audit_log_start+0x6f7/0x7a0 kernel/audit.c:1744
 audit_log+0x95/0x120 kernel/audit.c:2378
 xt_replace_table+0x61d/0x830 net/netfilter/x_tables.c:1418
 __do_replace+0x1da/0x930 net/ipv6/netfilter/ip6_tables.c:1087
 do_replace net/ipv6/netfilter/ip6_tables.c:1160 [inline]
 do_ip6t_set_ctl+0x327/0x498 net/ipv6/netfilter/ip6_tables.c:1684
 nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
 nf_setsockopt+0x77/0xd0 net/netfilter/nf_sockopt.c:115
 ipv6_setsockopt net/ipv6/ipv6_sockglue.c:938 [inline]
 ipv6_setsockopt+0x13e/0x170 net/ipv6/ipv6_sockglue.c:922
 tcp_setsockopt net/ipv4/tcp.c:3082 [inline]
 tcp_setsockopt+0x8f/0xe0 net/ipv4/tcp.c:3076
 sock_common_setsockopt+0x94/0xd0 net/core/sock.c:3046
 __sys_setsockopt+0x17a/0x280 net/socket.c:1901
 __do_sys_setsockopt net/socket.c:1912 [inline]
 __se_sys_setsockopt net/socket.c:1909 [inline]
 __x64_sys_setsockopt+0xbe/0x150 net/socket.c:1909
 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x44720a
Code: 49 89 ca b8 37 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 1a e0 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 fa df fb ff c3 66 0f 1f 84 00 00 00 00 00
RSP: 002b:00007ffea7d694e8 EFLAGS: 00000282 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000044720a
RDX: 0000000000000040 RSI: 0000000000000029 RDI: 0000000000000003
RBP: 00007ffea7d69610 R08: 00000000000003b8 R09: 0000000000004000
R10: 00000000006d7b40 R11: 0000000000000282 R12: 00007ffea7d69510
R13: 00000000006d9d60 R14: 0000000000000029 R15: 00000000006d7ba0
Kernel Offset: disabled
Rebooting in 86400 seconds..

Crashes (2):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-linux-4-19 2020/02/22 21:18 linux-4.19.y 4fccc2503536 2c36e7a7 .config log report syz C
ci2-linux-4-19 2020/02/22 16:57 linux-4.19.y 4fccc2503536 2c36e7a7 .config log report syz C
* Struck through repros no longer work on HEAD.