Hi!

I've got the following error report while running the syzkaller fuzzer.

A reproducer is attached.

On commit d8e435f3ab6fea2ea324dce72b51dd7761747523 (Nov 26).

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WARNING: CPU: 0 PID: 4009 at mm/page_alloc.c:3511
__alloc_pages_slowpath+0x3d4/0x1bf0
Modules linked in:
CPU: 0 PID: 4009 Comm: a.out Not tainted 4.9.0-rc6+ #54
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
 ffff88006832f8a8 ffffffff81c73b14 0000000000000000 0000000000000000
 ffffffff842c6320 0000000000000000 ffff88006832f8f0 ffffffff8123dc57
 ffff880067d86000 ffffffff00000db7 ffffffff842c6320 0000000000000db7
Call Trace:
 [<     inline     >] __dump_stack lib/dump_stack.c:15
 [<ffffffff81c73b14>] dump_stack+0xb3/0x10f lib/dump_stack.c:51
 [<ffffffff8123dc57>] __warn+0x1a7/0x1f0 kernel/panic.c:550
 [<ffffffff8123de6c>] warn_slowpath_null+0x2c/0x40 kernel/panic.c:585
 [<ffffffff81559b04>] __alloc_pages_slowpath+0x3d4/0x1bf0 mm/page_alloc.c:3511
 [<ffffffff8155b8e2>] __alloc_pages_nodemask+0x5c2/0x710 mm/page_alloc.c:3781
 [<ffffffff816236a4>] alloc_pages_current+0xf4/0x400 mm/mempolicy.c:2072
 [<     inline     >] alloc_pages ./include/linux/gfp.h:469
 [<ffffffff815a834f>] kmalloc_order+0x1f/0x70 mm/slab_common.c:1015
 [<ffffffff815a83bf>] kmalloc_order_trace+0x1f/0x160 mm/slab_common.c:1026
 [<     inline     >] kmalloc_large ./include/linux/slab.h:422
 [<ffffffff81635e67>] __kmalloc_track_caller+0x227/0x2a0 mm/slub.c:4233
 [<ffffffff8159932c>] memdup_user+0x2c/0xa0 mm/util.c:137
 [<ffffffff8369e0de>] raw_setsockopt+0x1be/0x9f0 net/can/raw.c:506
 [<     inline     >] SYSC_setsockopt net/socket.c:1757
 [<ffffffff82ca10c4>] SyS_setsockopt+0x154/0x240 net/socket.c:1736
 [<ffffffff840f2901>] entry_SYSCALL_64_fastpath+0x1f/0xc2
arch/x86/entry/entry_64.S:209
---[ end trace bc80556cca970089 ]---