CVE-2024-26989 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.

[catalin.marinas@arm.com: rework commit message]
Affected products: vendor: Linux
product: Linux
default_status: unaffected
vendor: Linux
product: Linux
default_status: affected
Published: 2024-05-01T05:27:44.067Z