arm64: hibernate: Fix level3 translation fault in swsusp_save()

In the Linux kernel, the following vulnerability has been resolved:

arm64: hibernate: Fix level3 translation fault in swsusp_save()

On arm64 machines, swsusp_save() faults if it attempts to access

MEMBLOCK_NOMAP memory ranges. This can be reproduced in QEMU using UEFI

when booting with rodata=off debug_pagealloc=off and CONFIG_KFENCE=n:

Unable to handle kernel paging request at virtual address ffffff8000000000

Mem abort info:

ESR = 0x0000000096000007

EC = 0x25: DABT (current EL), IL = 32 bits

SET = 0, FnV = 0

EA = 0, S1PTW = 0

FSC = 0x07: level 3 translation fault

Data abort info:

ISV = 0, ISS = 0x00000007, ISS2 = 0x00000000

CM = 0, WnR = 0, TnD = 0, TagAccess = 0

GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0

swapper pgtable: 4k pages, 39-bit VAs, pgdp=00000000eeb0b000

[ffffff8000000000] pgd=180000217fff9803, p4d=180000217fff9803, pud=180000217fff9803, pmd=180000217fff8803, pte=0000000000000000

Internal error: Oops: 0000000096000007 [#1] SMP

Internal error: Oops: 0000000096000007 [#1] SMP

Modules linked in: xt_multiport ipt_REJECT nf_reject_ipv4 xt_conntrack nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 libcrc32c iptable_filter bpfilter rfkill at803x snd_hda_codec_hdmi snd_hda_intel snd_intel_dspcfg dwmac_generic stmmac_platform snd_hda_codec stmmac joydev pcs_xpcs snd_hda_core phylink ppdev lp parport ramoops reed_solomon ip_tables x_tables nls_iso8859_1 vfat multipath linear amdgpu amdxcp drm_exec gpu_sched drm_buddy hid_generic usbhid hid radeon video drm_suballoc_helper drm_ttm_helper ttm i2c_algo_bit drm_display_helper cec drm_kms_helper drm

CPU: 0 PID: 3663 Comm: systemd-sleep Not tainted 6.6.2+ #76

Source Version: 4e22ed63a0a48e7a7cff9b98b7806d8d4add7dc0

Hardware name: Greatwall GW-XXXXXX-XXX/GW-XXXXXX-XXX, BIOS KunLun BIOS V4.0 01/19/2021

pstate: 600003c5 (nZCv DAIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)

pc : swsusp_save+0x280/0x538

lr : swsusp_save+0x280/0x538

sp : ffffffa034a3fa40

x29: ffffffa034a3fa40 x28: ffffff8000001000 x27: 0000000000000000

x26: ffffff8001400000 x25: ffffffc08113e248 x24: 0000000000000000

x23: 0000000000080000 x22: ffffffc08113e280 x21: 00000000000c69f2

x20: ffffff8000000000 x19: ffffffc081ae2500 x18: 0000000000000000

x17: 6666662074736420 x16: 3030303030303030 x15: 3038666666666666

x14: 0000000000000b69 x13: ffffff9f89088530 x12: 00000000ffffffea

x11: 00000000ffff7fff x10: 00000000ffff7fff x9 : ffffffc08193f0d0

x8 : 00000000000bffe8 x7 : c0000000ffff7fff x6 : 0000000000000001

x5 : ffffffa0fff09dc8 x4 : 0000000000000000 x3 : 0000000000000027

x2 : 0000000000000000 x1 : 0000000000000000 x0 : 000000000000004e

Call trace:

swsusp_save+0x280/0x538

swsusp_arch_suspend+0x148/0x190

hibernation_snapshot+0x240/0x39c

hibernate+0xc4/0x378

state_store+0xf0/0x10c

kobj_attr_store+0x14/0x24

The reason is swsusp_save() -> copy_data_pages() -> page_is_saveable()

-> kernel_page_present() assuming that a page is always present when

can_set_direct_map() is false (all of rodata_full,

debug_pagealloc_enabled() and arm64_kfence_can_set_direct_map() false),

irrespective of the MEMBLOCK_NOMAP ranges. Such MEMBLOCK_NOMAP regions

should not be saved during hibernation.

This problem was introduced by changes to the pfn_valid() logic in

commit a7d9f306ba70 ("arm64: drop pfn_valid_within() and simplify

pfn_valid()").

Similar to other architectures, drop the !can_set_direct_map() check in

kernel_page_present() so that page_is_savable() skips such pages.

[[email protected]: rework commit message]