Debian GNU/Linux 7 syzkaller ttyS0

net.ipv6.conf.syz0.accept_dad = 0
net.ipv6.conf.syz0.router_solicitations = 0
executing program
syzkaller login: [   17.805640] ------------[ cut here ]------------
[   17.806241] WARNING: CPU: 2 PID: 2980 at drivers/net/tun.c:1744 tun_get_user+0x2de3/0x36d0
[   17.807187] Kernel panic - not syncing: panic_on_warn set ...
[   17.807187] 
[   17.807944] CPU: 2 PID: 2980 Comm: syzkaller858010 Not tainted 4.14.0-rc5-next-20171018+ #8
[   17.808785] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
[   17.809605] Call Trace:
[   17.809877]  dump_stack+0x194/0x257
[   17.810221]  ? arch_local_irq_restore+0x53/0x53
[   17.810892]  ? vsnprintf+0x1ed/0x1900
[   17.811278]  panic+0x1e4/0x41c
[   17.811609]  ? refcount_error_report+0x214/0x214
[   17.811942]  ? show_regs_print_info+0x65/0x65
[   17.812339]  ? __warn+0x1a9/0x1e0
[   17.812691]  ? tun_get_user+0x2de3/0x36d0
[   17.813139]  __warn+0x1c4/0x1e0
[   17.813427]  ? tun_get_user+0x2de3/0x36d0
[   17.813790]  report_bug+0x211/0x2d0
[   17.815573]  fixup_bug+0x40/0x90
[   17.815886]  do_trap+0x260/0x390
[   17.816304]  do_error_trap+0x120/0x390
[   17.816657]  ? kfree_skbmem+0xe2/0x1d0
[   17.817009]  ? do_trap+0x390/0x390
[   17.817337]  ? __mutex_unlock_slowpath+0xe9/0xac0
[   17.817801]  ? tun_get_user+0x2de3/0x36d0
[   17.818191]  ? wait_for_completion+0x770/0x770
[   17.818617]  ? trace_hardirqs_off_thunk+0x1a/0x1c
[   17.819004]  do_invalid_op+0x1b/0x20
[   17.819288]  invalid_op+0x18/0x20
[   17.819557] RIP: 0010:tun_get_user+0x2de3/0x36d0
[   17.819908] RSP: 0018:ffff880068d2f730 EFLAGS: 00010286
[   17.820349] RAX: dffffc0000000000 RBX: ffff880039c7ab58 RCX: dffffc0000000000
[   17.820942] RDX: ffffffff87024140 RSI: 0000000000000000 RDI: 0000000000000282
[   17.821493] RBP: ffff880068d2fae0 R08: 0000000000000001 R09: 0000000000000000
[   17.822181] R10: ffffffff870692e0 R11: 0000000000000000 R12: ffff88006cd58c80
[   17.822864] R13: ffff880039c7abc8 R14: 0000000000000000 R15: ffff88003a5c0c00
[   17.823611]  ? __thp_get_unmapped_area+0x130/0x130
[   17.824143]  ? tun_build_skb.isra.48+0x16e0/0x16e0
[   17.824672]  ? kmem_cache_alloc+0x12e/0x760
[   17.825118]  ? do_mmap+0x69b/0xd40
[   17.825488]  ? vm_mmap_pgoff+0x1de/0x280
[   17.825888]  ? SyS_mmap_pgoff+0x23b/0x5f0
[   17.829808]  ? SyS_mmap+0x16/0x20
[   17.830138]  ? entry_SYSCALL_64_fastpath+0x1f/0xbe
[   17.830640]  ? trace_hardirqs_on+0xd/0x10
[   17.831069]  ? check_noncircular+0x20/0x20
[   17.831502]  ? tun_get+0x1ab/0x2e0
[   17.831850]  ? lock_release+0xa40/0xa40
[   17.832493]  ? __lock_is_held+0xb6/0x140
[   17.832919]  ? tun_get+0x1d4/0x2e0
[   17.833283]  ? tun_chr_close+0x60/0x60
[   17.833680]  ? __check_object_size+0x25d/0x4f0
[   17.834153]  ? rcu_note_context_switch+0x710/0x710
[   17.834643]  tun_chr_write_iter+0xb9/0x160
[   17.835058]  do_iter_readv_writev+0x525/0x7f0
[   17.835479]  ? vfs_dedupe_file_range+0x8f0/0x8f0
[   17.835890]  ? rw_verify_area+0xe5/0x2b0
[   17.836214]  do_iter_write+0x154/0x540
[   17.836539]  ? dup_iter+0x260/0x260
[   17.836843]  ? handle_mm_fault+0x410/0x8d0
[   17.837177]  ? __do_page_fault+0x31e/0xd60
[   17.837535]  vfs_writev+0x18a/0x340
[   17.837822]  ? __fget_light+0x297/0x380
[   17.838157]  ? vfs_iter_write+0xb0/0xb0
[   17.838502]  ? __do_page_fault+0x3d6/0xd60
[   17.838856]  ? down_read_killable+0x180/0x180
[   17.839253]  ? mm_fault_error+0x2c0/0x2c0
[   17.839649]  ? vm_mmap_pgoff+0x13b/0x280
[   17.839997]  ? __fdget_pos+0x130/0x190
[   17.840323]  ? do_page_fault+0xee/0x720
[   17.840654]  ? __fdget_raw+0x20/0x20
[   17.840963]  ? __do_page_fault+0xd60/0xd60
[   17.841326]  do_writev+0xfc/0x2a0
[   17.841613]  ? do_writev+0xfc/0x2a0
[   17.841918]  ? vfs_writev+0x340/0x340
[   17.842302]  ? entry_SYSCALL_64_fastpath+0x5/0xbe
[   17.842786]  ? trace_hardirqs_on_caller+0x421/0x5c0
[   17.843216]  SyS_writev+0x27/0x30
[   17.843509]  entry_SYSCALL_64_fastpath+0x1f/0xbe
[   17.843974] RIP: 0033:0x439c97
[   17.844280] RSP: 002b:00007ffc0a4b6ef8 EFLAGS: 00000246 ORIG_RAX: 0000000000000014
[   17.844921] RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000439c97
[   17.845535] RDX: 0000000000000002 RSI: 00007ffc0a4b6f10 RDI: 0000000000000003
[   17.846140] RBP: 0000000000000082 R08: 0000000000000018 R09: 0000000000000004
[   17.846761] R10: 000000000007adef R11: 0000000000000246 R12: 0000000000000000
[   17.847356] R13: 00000000004022b0 R14: 0000000000402340 R15: 0000000000000000
[   17.848081] Dumping ftrace buffer:
[   17.848437]    (ftrace buffer empty)
[   17.848747] Kernel Offset: disabled
[   17.849056] Rebooting in 86400 seconds..