Comment 2 for bug 1720779

Oops captured:

[ 207.012643] BUG: unable to handle kernel NULL pointer dereference at 0000000000000010
[ 207.012786] IP: memcpy_erms+0x6/0x10
[ 207.012787] PGD 0
[ 207.012787] P4D 0

[ 207.012788] Oops: 0000 [#1] SMP
[ 207.012789] Modules linked in: binfmt_misc snd_hda_codec_generic ppdev snd_hda_intel kvm_intel snd_hda_codec snd_hda_core kvm irqbypass snd_hwdep snd_pcm snd_timer snd joydev input_leds serio_raw soundcore qemu_fw_cfg mac_hid i2c_piix4 parport_pc parport ib_iser rdma_cm iw_cm ib_cm ib_core iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi ip_tables x_tables autofs4 btrfs raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c raid1 raid0 multipath linear crct10dif_pclmul crc32_pclmul ghash_clmulni_intel pcbc floppy aesni_intel aes_x86_64 crypto_simd glue_helper cryptd psmouse qxl ttm drm_kms_helper syscopyarea virtio_blk sysfillrect sysimgblt fb_sys_fops drm virtio_net pata_acpi
[ 207.012813] CPU: 0 PID: 3205 Comm: Not tainted 4.13.0-13-generic #14
[ 207.012813] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
[ 207.012814] task: ffff90c4f511ae80 task.stack: ffffb69082aec000
[ 207.012815] RIP: 0010:memcpy_erms+0x6/0x10
[ 207.012815] RSP: 0018:ffffb69082aefe08 EFLAGS: 00010286
[ 207.012816] RAX: ffff90c4f9da92d8 RBX: 0000000000000001 RCX: 0000000000000001
[ 207.012816] RDX: 0000000000000001 RSI: 0000000000000010 RDI: ffff90c4f9da92d8
[ 207.012816] RBP: ffffb69082aefe20 R08: ffff90c4ffc1f3e0 R09: ffff90c4fb003c80
[ 207.012817] R10: ffff90c4f9da92d8 R11: ffff90c4f511ae80 R12: 0000000000000010
[ 207.012817] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000010
[ 207.012818] FS: 00007f3b161e9740(0000) GS:ffff90c4ffc00000(0000) knlGS:0000000000000000
[ 207.012818] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 207.012819] CR2: 0000000000000010 CR3: 0000000132952000 CR4: 00000000001406f0
[ 207.012822] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 207.012822] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 207.012822] Call Trace:
[ 207.012825] ? kmemdup+0x31/0x40
[ 207.012827] security_setprocattr+0x6b/0x330
[ 207.012829] ? _copy_from_user+0x36/0x70
[ 207.012831] proc_pid_attr_write+0xdf/0x120
[ 207.012832] __vfs_write+0x18/0x40
[ 207.012833] vfs_write+0xb5/0x1a0
[ 207.012834] SyS_write+0x55/0xc0
[ 207.012836] entry_SYSCALL_64_fastpath+0x1e/0xa9
[ 207.012837] RIP: 0033:0x7f3b14ff1cc0
[ 207.012837] RSP: 002b:00007ffe18c71af0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
[ 207.012838] RAX: ffffffffffffffda RBX: 0000000000000008 RCX: 00007f3b14ff1cc0
[ 207.012838] RDX: 0000000000000000 RSI: 00007ffe18c72b80 RDI: 0000000000000008
[ 207.012838] RBP: 0000000000000008 R08: 0000000000000000 R09: 00007f3b161e9740
[ 207.012839] R10: 0000000000000000 R11: 0000000000000293 R12: 00007ffe18c71b80
[ 207.012839] R13: 0000000000000a6b R14: 00007ffe18c72b80 R15: 00007f3b161fa000
[ 207.012840] Code: 90 90 90 90 90 eb 1e 0f 1f 00 48 89 f8 48 89 d1 48 c1 e9 03 83 e2 07 f3 48 a5 89 d1 f3 a4 c3 66 0f 1f 44 00 00 48 89 f8 48 89 d1 <f3> a4 c3 0f 1f 80 00 00 00 00 48 89 f8 48 83 fa 20 72 7e 40 38
[ 207.012851] RIP: memcpy_erms+0x6/0x10 RSP: ffffb69082aefe08
[ 207.012851] CR2: 0000000000000010
[ 207.012852] ---[ end trace 960d89c5e7bec873 ]---