Re: kernel panic: audit: backlog limit exceeded

On Mon, Feb 24, 2020 at 5:43 PM Eric Paris <eparis(a)redhat.com&gt; wrote: > https://syzkaller.appspot.com/x/repro.syz?x=151b1109e00000 (the > reproducer listed) looks like it is literally fuzzing the AUDIT_SET. > Which seems like this is working as designed if it is setting the > failure mode to 2. So it is, good catch :) I saw the panic and instinctively chalked that up to a mistaken config, not expecting that it was what was being tested.

> On Mon, 2020-02-24 at 17:38 -0500, Paul Moore wrote: > > On Mon, Feb 24, 2020 at 3:18 AM syzbot > > <syzbot+9a5e789e4725b9ef1316(a)syzkaller.appspotmail.com&gt; wrote: > > > Hello, > > > > > > syzbot found the following crash on: > > > > > > HEAD commit: 36a44bcd Merge branch 'bnxt_en-shutdown-and-kexec- > > > kdump-re.. > > > git tree: net > > > console output: > > > https://syzkaller.appspot.com/x/log.txt?x=148bfdd9e00000 > > > kernel config: > > > https://syzkaller.appspot.com/x/.config?x=768cc3d3e277cc16 > > > dashboard link: > > > https://syzkaller.appspot.com/bug?extid=9a5e789e4725b9ef1316 > > > compiler: gcc (GCC) 9.0.0 20181231 (experimental) > > > syz repro: > > > https://syzkaller.appspot.com/x/repro.syz?x=151b1109e00000 > > > C reproducer: > > > https://syzkaller.appspot.com/x/repro.c?x=128bfdd9e00000 > > > > > > The bug was bisected to: > > > > > > commit 0c1b9970ddd4cc41002321c3877e7f91aacb896d > > > Author: Dan Carpenter <dan.carpenter(a)oracle.com&gt; > > > Date: Fri Jul 28 14:42:27 2017 +0000 > > > > > > staging: lustre: lustre: Off by two in lmv_fid2path() > > > > > > bisection log: > > > https://syzkaller.appspot.com/x/bisect.txt?x=17e6c3e9e00000 > > > final crash: > > > https://syzkaller.appspot.com/x/report.txt?x=1416c3e9e00000 > > > console output: > > > https://syzkaller.appspot.com/x/log.txt?x=1016c3e9e00000 > > > > > > IMPORTANT: if you fix the bug, please add the following tag to the > > > commit: > > > Reported-by: syzbot+9a5e789e4725b9ef1316(a)syzkaller.appspotmail.com > > > Fixes: 0c1b9970ddd4 ("staging: lustre: lustre: Off by two in > > > lmv_fid2path()") > > > > > > audit: audit_backlog=13 > audit_backlog_limit=7 > > > audit: audit_lost=1 audit_rate_limit=0 audit_backlog_limit=7 > > > Kernel panic - not syncing: audit: backlog limit exceeded > > > CPU: 1 PID: 9913 Comm: syz-executor024 Not tainted 5.6.0-rc1- > > > 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+0x2e3/0x75c kernel/panic.c:221 > > > audit_panic.cold+0x32/0x32 kernel/audit.c:307 > > > audit_log_lost kernel/audit.c:377 [inline] > > > audit_log_lost+0x8b/0x180 kernel/audit.c:349 > > > audit_log_start kernel/audit.c:1788 [inline] > > > audit_log_start+0x70e/0x7c0 kernel/audit.c:1745 > > > audit_log+0x95/0x120 kernel/audit.c:2345 > > > xt_replace_table+0x61d/0x830 net/netfilter/x_tables.c:1413 > > > __do_replace+0x1da/0x950 net/ipv6/netfilter/ip6_tables.c:1084 > > > do_replace net/ipv6/netfilter/ip6_tables.c:1157 [inline] > > > do_ip6t_set_ctl+0x33a/0x4c8 net/ipv6/netfilter/ip6_tables.c:1681 > > > 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:949 [inline] > > > ipv6_setsockopt+0x147/0x180 net/ipv6/ipv6_sockglue.c:933 > > > tcp_setsockopt net/ipv4/tcp.c:3165 [inline] > > > tcp_setsockopt+0x8f/0xe0 net/ipv4/tcp.c:3159 > > > sock_common_setsockopt+0x94/0xd0 net/core/sock.c:3149 > > > __sys_setsockopt+0x261/0x4c0 net/socket.c:2130 > > > __do_sys_setsockopt net/socket.c:2146 [inline] > > > __se_sys_setsockopt net/socket.c:2143 [inline] > > > __x64_sys_setsockopt+0xbe/0x150 net/socket.c:2143 > > > do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 > > > 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:00007ffd032dec78 EFLAGS: 00000286 ORIG_RAX: > > > 0000000000000036 > > > RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000044720a > > > RDX: 0000000000000040 RSI: 0000000000000029 RDI: 0000000000000003 > > > RBP: 00007ffd032deda0 R08: 00000000000003b8 R09: 0000000000004000 > > > R10: 00000000006d7b40 R11: 0000000000000286 R12: 00007ffd032deca0 > > > R13: 00000000006d9d60 R14: 0000000000000029 R15: 00000000006d7ba0 > > > Kernel Offset: disabled > > > Rebooting in 86400 seconds.. > > > > > > > > > --- > > > This bug is generated by a bot. It may contain errors. > > > See https://goo.gl/tpsmEJ for more information about syzbot. > > > syzbot engineers can be reached at syzkaller(a)googlegroups.com. > > > > > > syzbot will keep track of this bug report. See: > > > https://goo.gl/tpsmEJ#status for how to communicate with syzbot. > > > For information about bisection process see: > > > https://goo.gl/tpsmEJ#bisection > > > syzbot can test patches for this bug, for details see: > > > https://goo.gl/tpsmEJ#testing-patches > > > > Similar to syzbot report 72461ac44b36c98f58e5, see my comments there.