[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 46.290872][ T26] audit: type=1800 audit(1555325448.030:25): pid=8131 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 46.318521][ T26] audit: type=1800 audit(1555325448.030:26): pid=8131 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 46.340219][ T26] audit: type=1800 audit(1555325448.030:27): pid=8131 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="restorecond" dev="sda1" ino=2436 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 '10.128.0.196' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 58.269798][ T8280] WARNING: CPU: 1 PID: 8280 at include/linux/cpumask.h:121 io_uring_setup+0x13cd/0x1a30 [ 58.279657][ T8280] Kernel panic - not syncing: panic_on_warn set ... [ 58.286269][ T8280] CPU: 1 PID: 8280 Comm: syz-executor974 Not tainted 5.1.0-rc5 #68 [ 58.294153][ T8280] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 58.304221][ T8280] Call Trace: [ 58.307592][ T8280] dump_stack+0x172/0x1f0 [ 58.311932][ T8280] ? io_uring_setup+0x1390/0x1a30 [ 58.317034][ T8280] panic+0x2cb/0x65c [ 58.320936][ T8280] ? __warn_printk+0xf3/0xf3 [ 58.325533][ T8280] ? io_uring_setup+0x13cd/0x1a30 [ 58.330647][ T8280] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 58.336894][ T8280] ? __warn.cold+0x5/0x45 [ 58.341245][ T8280] ? __warn+0xe8/0x1d0 [ 58.345345][ T8280] ? io_uring_setup+0x13cd/0x1a30 [ 58.350371][ T8280] __warn.cold+0x20/0x45 [ 58.354617][ T8280] ? io_uring_setup+0x13cd/0x1a30 [ 58.359654][ T8280] report_bug+0x263/0x2b0 [ 58.364007][ T8280] do_error_trap+0x11b/0x200 [ 58.368623][ T8280] do_invalid_op+0x37/0x50 [ 58.373054][ T8280] ? io_uring_setup+0x13cd/0x1a30 [ 58.378087][ T8280] invalid_op+0x14/0x20 [ 58.382260][ T8280] RIP: 0010:io_uring_setup+0x13cd/0x1a30 [ 58.387891][ T8280] Code: 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 0f 84 18 fe ff ff 48 8b bd e8 fe ff ff e8 2d 80 e0 ff e9 07 fe ff ff e8 73 70 a8 ff <0f> 0b e9 bc f8 ff ff e8 67 70 a8 ff 49 8d 84 24 88 00 00 00 48 89 [ 58.407504][ T8280] RSP: 0018:ffff8880aa34fdb0 EFLAGS: 00010293 [ 58.413572][ T8280] RAX: ffff88808cf64080 RBX: 00000000ffffffff RCX: ffffffff81c814f7 [ 58.421544][ T8280] RDX: 0000000000000000 RSI: ffffffff81c81c3d RDI: 0000000000000005 [ 58.429518][ T8280] RBP: ffff8880aa34fee0 R08: ffff88808cf64080 R09: ffffed1013f81a8c [ 58.437578][ T8280] R10: ffffed1013f81a8b R11: ffff88809fc0d45f R12: ffff88809fa3cec0 [ 58.445554][ T8280] R13: ffff8880aa34feb8 R14: ffff88809fa3cf50 R15: ffff88809fa3cf14 [ 58.453583][ T8280] ? io_uring_setup+0xc87/0x1a30 [ 58.458535][ T8280] ? io_uring_setup+0x13cd/0x1a30 [ 58.463573][ T8280] ? io_uring_release+0x50/0x50 [ 58.469828][ T8280] ? lock_downgrade+0x880/0x880 [ 58.474975][ T8280] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 58.480476][ T8280] ? do_fast_syscall_32+0xd1/0xc98 [ 58.485655][ T8280] ? entry_SYSENTER_compat+0x70/0x7f [ 58.491244][ T8280] ? do_fast_syscall_32+0xd1/0xc98 [ 58.496586][ T8280] ? lockdep_hardirqs_on+0x418/0x5d0 [ 58.502223][ T8280] __ia32_sys_io_uring_setup+0x53/0x70 [ 58.507822][ T8280] do_fast_syscall_32+0x281/0xc98 [ 58.513097][ T8280] entry_SYSENTER_compat+0x70/0x7f [ 58.518221][ T8280] RIP: 0023:0xf7f1e869 [ 58.522292][ T8280] Code: 85 d2 74 02 89 0a 5b 5d c3 8b 04 24 c3 8b 14 24 c3 8b 3c 24 c3 90 90 90 90 90 90 90 90 90 90 90 90 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90 [ 58.544100][ T8280] RSP: 002b:00000000fff5f21c EFLAGS: 00000282 ORIG_RAX: 00000000000001a9 [ 58.558336][ T8280] RAX: ffffffffffffffda RBX: 000000000000014a RCX: 0000000020000140 [ 58.566441][ T8280] RDX: 0000000000000002 RSI: 00000000080ea070 RDI: 00000000fff5f270 [ 58.574413][ T8280] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 [ 58.582381][ T8280] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 58.590528][ T8280] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 58.599707][ T8280] Kernel Offset: disabled [ 58.604151][ T8280] Rebooting in 86400 seconds..