[ 76.827858][ T26] audit: type=1800 audit(1584389611.085:24): pid=9576 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="sudo" dev="sda1" ino=2454 res=0 [....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 77.524993][ T26] audit: type=1800 audit(1584389611.885:25): pid=9576 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 77.550197][ T26] audit: type=1800 audit(1584389611.895:26): pid=9576 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.0.42' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 90.250654][ T9730] IPVS: ftp: loaded support on port[0] = 21 [ 90.282062][ T9730] netlink: 16 bytes leftover after parsing attributes in process `syz-executor932'. [ 90.350991][ T9730] ------------[ cut here ]------------ [ 90.356486][ T9730] refcount_t: underflow; use-after-free. [ 90.362650][ T9730] WARNING: CPU: 1 PID: 9730 at lib/refcount.c:28 refcount_warn_saturate+0x1d1/0x1e0 [ 90.372025][ T9730] Kernel panic - not syncing: panic_on_warn set ... [ 90.378609][ T9730] CPU: 1 PID: 9730 Comm: syz-executor932 Not tainted 5.6.0-rc5-syzkaller #0 [ 90.387246][ T9730] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 90.397292][ T9730] Call Trace: [ 90.400562][ T9730] dump_stack+0x188/0x20d [ 90.404913][ T9730] ? refcount_warn_saturate+0x1d0/0x1e0 [ 90.410461][ T9730] panic+0x2e3/0x75c [ 90.414349][ T9730] ? add_taint.cold+0x16/0x16 [ 90.419045][ T9730] ? __probe_kernel_read+0x188/0x1d0 [ 90.424329][ T9730] ? __warn.cold+0x14/0x35 [ 90.428721][ T9730] ? __warn+0xd5/0x1c8 [ 90.432769][ T9730] ? refcount_warn_saturate+0x1d1/0x1e0 [ 90.438289][ T9730] __warn.cold+0x2f/0x35 [ 90.442527][ T9730] ? refcount_warn_saturate+0x1d1/0x1e0 [ 90.448069][ T9730] report_bug+0x27b/0x2f0 [ 90.452377][ T9730] do_error_trap+0x12b/0x220 [ 90.456955][ T9730] ? refcount_warn_saturate+0x1d1/0x1e0 [ 90.462487][ T9730] do_invalid_op+0x32/0x40 [ 90.466873][ T9730] ? refcount_warn_saturate+0x1d1/0x1e0 [ 90.472425][ T9730] invalid_op+0x23/0x30 [ 90.476552][ T9730] RIP: 0010:refcount_warn_saturate+0x1d1/0x1e0 [ 90.482693][ T9730] Code: e9 db fe ff ff 48 89 df e8 ec 10 20 fe e9 8a fe ff ff e8 d2 4f e3 fd 48 c7 c7 80 aa 51 88 c6 05 85 66 d2 06 01 e8 17 60 b5 fd <0f> 0b e9 af fe ff ff 0f 1f 84 00 00 00 00 00 41 56 41 55 41 54 55 [ 90.502278][ T9730] RSP: 0018:ffffc90001d67d38 EFLAGS: 00010286 [ 90.508326][ T9730] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 [ 90.516276][ T9730] RDX: 0000000000000000 RSI: ffffffff815bf511 RDI: fffff520003acf99 [ 90.524223][ T9730] RBP: 0000000000000003 R08: ffff8880961c8200 R09: ffffed1015ce6659 [ 90.532170][ T9730] R10: ffffed1015ce6658 R11: ffff8880ae7332c7 R12: ffff8880a2ece040 [ 90.540120][ T9730] R13: ffff8880a2ece044 R14: 00000000000002ab R15: ffff88809dc1d680 [ 90.548080][ T9730] ? vprintk_func+0x81/0x17e [ 90.552649][ T9730] ? refcount_warn_saturate+0x1d1/0x1e0 [ 90.558196][ T9730] free_nsproxy+0x445/0x4a0 [ 90.562678][ T9730] switch_task_namespaces+0xaa/0xc0 [ 90.567853][ T9730] do_exit+0xb2f/0x2dd0 [ 90.571996][ T9730] ? mm_update_next_owner+0x7a0/0x7a0 [ 90.577340][ T9730] ? up_read+0x1ab/0x750 [ 90.581568][ T9730] ? mark_held_locks+0x9f/0xe0 [ 90.586301][ T9730] ? down_read_non_owner+0x470/0x470 [ 90.591566][ T9730] ? handle_mm_fault+0x491/0xa10 [ 90.596484][ T9730] do_group_exit+0x125/0x340 [ 90.601051][ T9730] __x64_sys_exit_group+0x3a/0x50 [ 90.606064][ T9730] do_syscall_64+0xf6/0x7d0 [ 90.610576][ T9730] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 90.616436][ T9730] RIP: 0033:0x43f998 [ 90.620314][ T9730] Code: 24 38 80 f9 3a 0f 85 5f 01 00 00 48 8d 74 24 34 48 8d 7c 24 38 83 ea 01 89 54 24 34 e8 61 f8 ff ff 83 f8 3c 41 89 c1 0f 87 3d <01> 00 00 8b 4c 24 34 85 c9 0f 8e 59 01 00 00 48 8b 54 24 38 c7 44 [ 90.639888][ T9730] RSP: 002b:00007ffe8595d3c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 90.648268][ T9730] RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 000000000043f998 [ 90.656213][ T9730] RDX: 0000000000000001 RSI: 000000000000003c RDI: 0000000000000001 [ 90.664162][ T9730] RBP: 00000000004bfa10 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 90.672112][ T9730] R10: 0000000120080522 R11: 0000000000000246 R12: 0000000000000001 [ 90.680081][ T9730] R13: 00000000006d11c0 R14: 0000000000000000 R15: 0000000000000000 [ 90.689228][ T9730] Kernel Offset: disabled [ 90.693597][ T9730] Rebooting in 86400 seconds..