[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. [ 28.568247] kauditd_printk_skb: 7 callbacks suppressed [ 28.568259] audit: type=1800 audit(1543697169.506:29): pid=5893 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="rc.local" dev="sda1" ino=2432 res=0 [ 28.593756] audit: type=1800 audit(1543697169.516:30): pid=5893 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="rmnologin" dev="sda1" ino=2423 res=0 Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.0.27' (ECDSA) to the list of known hosts. syzkaller login: [ 36.195544] IPVS: ftp: loaded support on port[0] = 21 executing program [ 36.275306] WARNING: CPU: 1 PID: 6047 at fs/userfaultfd.c:1569 userfaultfd_ioctl+0x3d30/0x5610 [ 36.284149] Kernel panic - not syncing: panic_on_warn set ... [ 36.290021] CPU: 1 PID: 6047 Comm: syz-executor638 Not tainted 4.20.0-rc4+ #261 [ 36.297444] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 36.306776] Call Trace: [ 36.309347] dump_stack+0x244/0x39d [ 36.312963] ? dump_stack_print_info.cold.1+0x20/0x20 [ 36.318144] panic+0x2ad/0x55c [ 36.321323] ? add_taint.cold.5+0x16/0x16 [ 36.325460] ? __warn.cold.8+0x5/0x45 [ 36.329242] ? __warn+0xe8/0x1d0 [ 36.332596] ? userfaultfd_ioctl+0x3d30/0x5610 [ 36.337167] __warn.cold.8+0x20/0x45 [ 36.340863] ? rcu_softirq_qs+0x20/0x20 [ 36.344820] ? userfaultfd_ioctl+0x3d30/0x5610 [ 36.349401] report_bug+0x254/0x2d0 [ 36.353014] do_error_trap+0x11b/0x200 [ 36.356886] do_invalid_op+0x36/0x40 [ 36.360581] ? userfaultfd_ioctl+0x3d30/0x5610 [ 36.365165] invalid_op+0x14/0x20 [ 36.368600] RIP: 0010:userfaultfd_ioctl+0x3d30/0x5610 [ 36.373781] Code: 85 c0 f6 ff ff 48 c1 e8 03 42 80 3c 30 00 0f 84 a3 fa ff ff 48 8b bd c0 f6 ff ff e8 4a 60 db ff e9 92 fa ff ff e8 20 07 98 ff <0f> 0b e9 cd f7 ff ff e8 14 07 98 ff 48 8b 95 f0 f6 ff ff b9 01 00 [ 36.392679] RSP: 0018:ffff8881c11ff3d0 EFLAGS: 00010293 [ 36.398032] RAX: ffff8881c17a6000 RBX: 00000000080000d0 RCX: ffffffff81e77b7b [ 36.405297] RDX: 0000000000000000 RSI: ffffffff81e783b0 RDI: 0000000000000007 [ 36.412549] RBP: ffff8881c11ffd60 R08: ffff8881c17a6000 R09: 0000000000000008 [ 36.419810] R10: 0000000000003cb4 R11: ffff8881c17a6000 R12: 0000000020011000 [ 36.427078] R13: 0000000000000000 R14: dffffc0000000000 R15: ffff8881d82dc358 [ 36.434336] ? userfaultfd_ioctl+0x34fb/0x5610 [ 36.438897] ? userfaultfd_ioctl+0x3d30/0x5610 [ 36.443465] ? lru_cache_add+0xa50/0xa50 [ 36.447517] ? userfaultfd_read+0x2c0/0x2c0 [ 36.451830] ? do_huge_pmd_anonymous_page+0x14a3/0x2150 [ 36.457180] ? lock_downgrade+0x900/0x900 [ 36.461311] ? pudp_huge_clear_flush+0x390/0x390 [ 36.466055] ? kasan_check_read+0x11/0x20 [ 36.470187] ? do_raw_spin_unlock+0xa7/0x330 [ 36.474581] ? do_raw_spin_trylock+0x270/0x270 [ 36.479144] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 36.484664] ? clear_subpage+0xdc/0x100 [ 36.488625] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 36.493634] ? _raw_spin_unlock+0x2c/0x50 [ 36.497771] ? __thp_get_unmapped_area+0x180/0x180 [ 36.502700] ? uprobe_apply+0x140/0x140 [ 36.506654] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 36.512173] ? print_usage_bug+0xc0/0xc0 [ 36.516216] ? print_usage_bug+0xc0/0xc0 [ 36.520265] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 36.525782] ? vma_set_page_prot+0x243/0x320 [ 36.530176] ? __lock_acquire+0x62f/0x4c20 [ 36.534396] ? __lock_acquire+0x62f/0x4c20 [ 36.538611] ? mmap_region+0x62f/0x1cd0 [ 36.542577] ? mark_held_locks+0x130/0x130 [ 36.546830] ? mark_held_locks+0x130/0x130 [ 36.551044] ? zap_class+0x640/0x640 [ 36.554742] ? mpx_unmapped_area_check+0xd8/0x108 [ 36.559586] ? __handle_mm_fault+0xa57/0x5be0 [ 36.564065] ? find_held_lock+0x36/0x1c0 [ 36.568120] ? vmf_insert_mixed_mkwrite+0x40/0x40 [ 36.572947] ? vm_mmap_pgoff+0x222/0x2c0 [ 36.577005] ? lock_downgrade+0x900/0x900 [ 36.581148] ? __sanitizer_cov_trace_cmp8+0x18/0x20 [ 36.586165] ? cap_mmap_addr+0x52/0x130 [ 36.590129] ? userfaultfd_unmap_complete+0x32a/0x510 [ 36.595305] ? security_mmap_addr+0x80/0xa0 [ 36.599630] ? zap_class+0x640/0x640 [ 36.603334] ? zap_class+0x640/0x640 [ 36.607028] ? zap_class+0x640/0x640 [ 36.610724] ? find_held_lock+0x36/0x1c0 [ 36.614768] ? __do_page_fault+0x620/0xe60 [ 36.618984] ? lock_downgrade+0x900/0x900 [ 36.623119] ? rcu_read_unlock_special+0x1c0/0x1c0 [ 36.628039] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 36.633558] ? __fget_light+0x2e9/0x430 [ 36.637530] ? fget_raw+0x20/0x20 [ 36.640983] ? check_preemption_disabled+0x48/0x280 [ 36.645984] ? kasan_check_write+0x14/0x20 [ 36.650199] ? up_read+0x225/0x2c0 [ 36.653720] ? do_fast_syscall_32+0x150/0xfb2 [ 36.658211] ? lockdep_hardirqs_on+0x3bb/0x5b0 [ 36.662777] ? userfaultfd_read+0x2c0/0x2c0 [ 36.667078] __ia32_compat_sys_ioctl+0x20e/0x630 [ 36.671816] ? userfaultfd_read+0x2c0/0x2c0 [ 36.676122] ? __ia32_compat_sys_ioctl+0x20e/0x630 [ 36.681058] do_fast_syscall_32+0x34d/0xfb2 [ 36.685379] ? do_int80_syscall_32+0x890/0x890 [ 36.689957] ? entry_SYSENTER_compat+0x68/0x7f [ 36.694537] ? trace_hardirqs_off_caller+0xbb/0x310 [ 36.699534] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 36.704356] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 36.709179] ? trace_hardirqs_on_caller+0x310/0x310 [ 36.714177] ? prepare_exit_to_usermode+0x3b0/0x3b0 [ 36.719172] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 36.724691] ? prepare_exit_to_usermode+0x291/0x3b0 [ 36.729686] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 36.734544] entry_SYSENTER_compat+0x70/0x7f [ 36.738929] RIP: 0023:0xf7fb7a29 [ 36.742276] 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 [ 36.761156] RSP: 002b:00000000081fff3c EFLAGS: 00000202 ORIG_RAX: 0000000000000036 [ 36.768859] RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000008010aa01 [ 36.776115] RDX: 0000000020d62fe0 RSI: 0000000000000000 RDI: 0000000000000000 [ 36.783371] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 [ 36.790623] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 36.797875] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 36.806213] Kernel Offset: disabled [ 36.809893] Rebooting in 86400 seconds..