[lkp-robot] [net] a1a22c1206: BUG:unable_to_handle_kernel

FYI, we noticed the following commit:

commit: a1a22c12060e4b9c52f45d4b3460f614e00162a2 ("net: ipv6: Keep nexthop of multipath route on admin down")
https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git master

in testcase: trinity
with following parameters:

	runtime: 300s

test-description: Trinity is a linux system call fuzz tester.
test-url: http://codemonkey.org.uk/projects/trinity/


on test machine: qemu-system-i386 -enable-kvm -m 320M

caused below changes:


+-------------------------------------------------------+------------+------------+
|                                                       | dceeab0e52 | a1a22c1206 |
+-------------------------------------------------------+------------+------------+
| boot_successes                                        | 8          | 4          |
| boot_failures                                         | 0          | 4          |
| BUG:unable_to_handle_kernel                           | 0          | 4          |
| Oops:#[##]                                            | 0          | 4          |
| Kernel_panic-not_syncing:Fatal_exception_in_interrupt | 0          | 4          |
+-------------------------------------------------------+------------+------------+



[  150.634538] ubus (612) used greatest stack depth: 6716 bytes left
[  151.925694] ubus (647) used greatest stack depth: 6616 bytes left
[  154.978628] ubus (724) used greatest stack depth: 6604 bytes left
[  158.324778] BUG: unable to handle kernel NULL pointer dereference at 00000198
[  158.334111] IP: rt6_fill_node+0x14e/0x4a6
[  158.339546] *pdpt = 000000000f789001 *pde = 0000000000000000 
[  158.339554] 
[  158.349075] Oops: 0000 [#1]
[  158.353060] CPU: 0 PID: 726 Comm: netifd Not tainted 4.10.0-rc4-00660-ga1a22c1 #1
[  158.362818] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.3-20161025_171302-gandalf 04/01/2014
[  158.375911] task: cf751000 task.stack: cf78c000
[  158.381810] EIP: rt6_fill_node+0x14e/0x4a6
[  158.386925] EFLAGS: 00010246 CPU: 0
[  158.392921] EAX: 00000000 EBX: d1f6c358 ECX: cec03f40 EDX: 00000000
[  158.400763] ESI: cf78dbf8 EDI: 00000000 EBP: cf78dc54 ESP: cf78dbe8
[  158.408870]  DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 0068
[  158.415864] CR0: 80050033 CR2: 00000198 CR3: 12e50220 CR4: 000006b0
[  158.423771] Call Trace:
[  158.426955]  ? paravirt_sched_clock+0x9/0xd
[  158.432069]  ? sched_clock+0x9/0xc
[  158.436702]  ? sched_clock_cpu+0x1a/0xe1


To reproduce:

        git clone git://git.kernel.org/pub/scm/linux/kernel/git/wfg/lkp-tests.git
        cd lkp-tests
        bin/lkp qemu -k <bzImage> job-script  # job-script is attached in this email



Thanks,
Xiaolong