device gre0 entered promiscuous mode
==================================================================
BUG: KASAN: stack-out-of-bounds in iov_iter_advance+0x4c0/0x4f0 lib/iov_iter.c:491
Read of size 8 at addr ffff8800b4027cc0 by task syzkaller142637/3316

CPU: 0 PID: 3316 Comm: syzkaller142637 Not tainted 4.4.107-g610c835 #4
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 0000000000000000 9e1bd450b5d201d4 ffff8800b4027900 ffffffff81d0457d
 ffffea0002d009c0 ffff8800b4027cc0 0000000000000000 ffff8800b4027cc0
 ffff8800b4027cb8 ffff8800b4027938 ffffffff814fbb23 ffff8800b4027cc0
Call Trace:
 [<ffffffff81d0457d>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81d0457d>] dump_stack+0xc1/0x124 lib/dump_stack.c:51
 [<ffffffff814fbb23>] print_address_description+0x73/0x260 mm/kasan/report.c:252
 [<ffffffff814fc035>] kasan_report_error mm/kasan/report.c:351 [inline]
 [<ffffffff814fc035>] kasan_report+0x285/0x370 mm/kasan/report.c:408
 [<ffffffff814fc194>] __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:429
 [<ffffffff81d3f240>] iov_iter_advance+0x4c0/0x4f0 lib/iov_iter.c:491
 [<ffffffff8265609b>] tun_put_user drivers/net/tun.c:1369 [inline]
 [<ffffffff8265609b>] tun_do_read+0xa7b/0xcc0 drivers/net/tun.c:1421
 [<ffffffff82658e82>] tun_chr_read_iter+0xe2/0x1e0 drivers/net/tun.c:1439
 [<ffffffff8151aca9>] new_sync_read fs/read_write.c:422 [inline]
 [<ffffffff8151aca9>] __vfs_read+0x339/0x440 fs/read_write.c:434
 [<ffffffff8151c913>] vfs_read+0x123/0x3a0 fs/read_write.c:454
 [<ffffffff8151f259>] SYSC_read fs/read_write.c:569 [inline]
 [<ffffffff8151f259>] SyS_read+0xd9/0x1b0 fs/read_write.c:562
 [<ffffffff81006d84>] do_syscall_32_irqs_on arch/x86/entry/common.c:390 [inline]
 [<ffffffff81006d84>] do_fast_syscall_32+0x314/0x890 arch/x86/entry/common.c:457
 [<ffffffff837754d7>] sysenter_flags_fixed+0xd/0x17

The buggy address belongs to the page:
page:ffffea0002d009c0 count:0 mapcount:0 mapping:          (null) index:0x0
flags: 0x4000000000000000()
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8800b4027b80: f2 f2 f2 f2 f2 f2 00 02 f2 f2 00 00 00 00 00 00
 ffff8800b4027c00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8800b4027c80: 00 f1 f1 f1 f1 00 00 f2 f2 f2 f2 f2 f2 00 00 00
                                           ^
 ffff8800b4027d00: 00 00 f2 f2 f2 f2 f2 f2 f2 00 00 00 00 00 f2 f2
 ffff8800b4027d80: f2 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================
Kernel panic - not syncing: panic_on_warn set ...

CPU: 0 PID: 3316 Comm: syzkaller142637 Tainted: G    B           4.4.107-g610c835 #4
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 0000000000000000 9e1bd450b5d201d4 ffff8800b4027858 ffffffff81d0457d
 ffffffff83fb2cde ffff8800b4027930 0000000000000000 ffff8800b4027cc0
 ffff8800b4027cb8 ffff8800b4027920 ffffffff8141774a 0000000041b58ab3
Call Trace:
 [<ffffffff81d0457d>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81d0457d>] dump_stack+0xc1/0x124 lib/dump_stack.c:51
 [<ffffffff8141774a>] panic+0x1aa/0x388 kernel/panic.c:112
 [<ffffffff814fba90>] kasan_end_report+0x50/0x50 mm/kasan/report.c:176
 [<ffffffff814fbf0c>] kasan_report_error mm/kasan/report.c:356 [inline]
 [<ffffffff814fbf0c>] kasan_report+0x15c/0x370 mm/kasan/report.c:408
 [<ffffffff814fc194>] __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:429
 [<ffffffff81d3f240>] iov_iter_advance+0x4c0/0x4f0 lib/iov_iter.c:491
 [<ffffffff8265609b>] tun_put_user drivers/net/tun.c:1369 [inline]
 [<ffffffff8265609b>] tun_do_read+0xa7b/0xcc0 drivers/net/tun.c:1421
 [<ffffffff82658e82>] tun_chr_read_iter+0xe2/0x1e0 drivers/net/tun.c:1439
 [<ffffffff8151aca9>] new_sync_read fs/read_write.c:422 [inline]
 [<ffffffff8151aca9>] __vfs_read+0x339/0x440 fs/read_write.c:434
 [<ffffffff8151c913>] vfs_read+0x123/0x3a0 fs/read_write.c:454
 [<ffffffff8151f259>] SYSC_read fs/read_write.c:569 [inline]
 [<ffffffff8151f259>] SyS_read+0xd9/0x1b0 fs/read_write.c:562
 [<ffffffff81006d84>] do_syscall_32_irqs_on arch/x86/entry/common.c:390 [inline]
 [<ffffffff81006d84>] do_fast_syscall_32+0x314/0x890 arch/x86/entry/common.c:457
 [<ffffffff837754d7>] sysenter_flags_fixed+0xd/0x17
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..