INIT: Entering runlevel: 2 [info] Using makefile-style concurrent boot in runlevel 2. [....] 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. Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added 'ci-upstream-next-kasan-gce-8,10.128.0.31' (ECDSA) to the list of known hosts. net.ipv6.conf.syz0.accept_dad = 0 net.ipv6.conf.syz0.router_solicitations = 0 executing program syzkaller login: [ 42.284704] ------------[ cut here ]------------ [ 42.285513] WARNING: CPU: 1 PID: 2990 at drivers/net/tun.c:1744 tun_get_user+0x2de3/0x36d0 [ 42.286800] Kernel panic - not syncing: panic_on_warn set ... [ 42.286800] [ 42.287772] CPU: 1 PID: 2990 Comm: syzkaller959817 Not tainted 4.14.0-rc5-next-20171018+ #36 [ 42.288892] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 42.290111] Call Trace: [ 42.290473] dump_stack+0x194/0x257 [ 42.290965] ? arch_local_irq_restore+0x53/0x53 [ 42.291591] ? vsnprintf+0x1ed/0x1900 [ 42.292108] panic+0x1e4/0x41c [ 42.292542] ? refcount_error_report+0x214/0x214 [ 42.293220] ? show_regs_print_info+0x65/0x65 [ 42.293827] ? __warn+0x1a9/0x1e0 [ 42.294298] ? tun_get_user+0x2de3/0x36d0 [ 42.294854] __warn+0x1c4/0x1e0 [ 42.295298] ? tun_get_user+0x2de3/0x36d0 [ 42.295856] report_bug+0x211/0x2d0 [ 42.296353] fixup_bug+0x40/0x90 [ 42.296809] do_trap+0x260/0x390 [ 42.297270] do_error_trap+0x120/0x390 [ 42.297793] ? kfree_skbmem+0xe2/0x1d0 [ 42.298317] ? do_trap+0x390/0x390 [ 42.298794] ? __mutex_unlock_slowpath+0xe9/0xac0 [ 42.299438] ? tun_get_user+0x2de3/0x36d0 [ 42.299994] ? wait_for_completion+0x770/0x770 [ 42.300611] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 42.301276] do_invalid_op+0x1b/0x20 [ 42.301775] invalid_op+0x18/0x20 [ 42.302240] RIP: 0010:tun_get_user+0x2de3/0x36d0 [ 42.302869] RSP: 0018:ffff8801c0437730 EFLAGS: 00010286 [ 42.303580] RAX: dffffc0000000000 RBX: ffff8801d1daba98 RCX: dffffc0000000000 [ 42.304532] RDX: ffffffff87024140 RSI: 0000000000000000 RDI: 0000000000000282 [ 42.309904] RBP: ffff8801c0437ae0 R08: 0000000000000001 R09: 0000000000000000 [ 42.317141] R10: ffffffff870692e0 R11: 0000000000000000 R12: ffff8801d13ac580 [ 42.324377] R13: ffff8801d1dabb08 R14: 0000000000000000 R15: ffff8801d1d90d40 [ 42.331651] ? tun_build_skb.isra.48+0x16e0/0x16e0 [ 42.336552] ? __bpf_prog_release+0xb1/0xf0 [ 42.340839] ? bpf_prepare_filter+0x2e7/0xe00 [ 42.345306] ? check_noncircular+0x20/0x20 [ 42.349525] ? tun_get+0x1ab/0x2e0 [ 42.353038] ? do_seccomp+0x1c7b/0x21f0 [ 42.356980] ? lock_release+0xa40/0xa40 [ 42.360924] ? __lock_is_held+0xb6/0x140 [ 42.364960] ? tun_get+0x1d4/0x2e0 [ 42.368468] ? tun_chr_close+0x60/0x60 [ 42.372325] ? __check_object_size+0x25d/0x4f0 [ 42.376875] ? rcu_note_context_switch+0x710/0x710 [ 42.381786] tun_chr_write_iter+0xb9/0x160 [ 42.385993] do_iter_readv_writev+0x525/0x7f0 [ 42.390462] ? vfs_dedupe_file_range+0x8f0/0x8f0 [ 42.395192] ? rw_verify_area+0xe5/0x2b0 [ 42.399225] do_iter_write+0x154/0x540 [ 42.403084] ? dup_iter+0x260/0x260 [ 42.406685] vfs_writev+0x18a/0x340 [ 42.410277] ? __fget_light+0x297/0x380 [ 42.414221] ? vfs_iter_write+0xb0/0xb0 [ 42.418164] ? up_read+0x1a/0x40 [ 42.421501] ? __do_page_fault+0x3d6/0xd60 [ 42.425703] ? security_mmap_file+0x143/0x180 [ 42.430172] ? mm_fault_error+0x2c0/0x2c0 [ 42.434294] ? __fdget_pos+0x130/0x190 [ 42.438150] ? __fdget_raw+0x20/0x20 [ 42.441831] ? __do_page_fault+0xd60/0xd60 [ 42.446036] do_writev+0xfc/0x2a0 [ 42.449454] ? do_writev+0xfc/0x2a0 [ 42.453052] ? vfs_writev+0x340/0x340 [ 42.456820] ? entry_SYSCALL_64_fastpath+0x5/0xbe [ 42.461631] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 42.466619] SyS_writev+0x27/0x30 [ 42.470040] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 42.474760] RIP: 0033:0x444b30 [ 42.477915] RSP: 002b:00007fffc6c898e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000014 [ 42.485587] RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000444b30 [ 42.492823] RDX: 0000000000000002 RSI: 00007fffc6c898f0 RDI: 0000000000000003 [ 42.500058] RBP: 0000000000000082 R08: 0000000000000000 R09: 0000000000000001 [ 42.507292] R10: 0000000002000004 R11: 0000000000000246 R12: 0000000000402240 [ 42.514527] R13: 00000000004022d0 R14: 0000000000000000 R15: 0000000000000000 [ 42.521938] Dumping ftrace buffer: [ 42.525495] (ftrace buffer empty) [ 42.529174] Kernel Offset: disabled [ 42.532773] Rebooting in 86400 seconds..