CVE-2022-50675 (GCVE-0-2022-50675)

Vulnerability from cvelistv5 – Published: 2025-12-09 01:29 – Updated: 2025-12-09 01:29
VLAI?
Title
arm64: mte: Avoid setting PG_mte_tagged if no tags cleared or restored
Summary
In the Linux kernel, the following vulnerability has been resolved: arm64: mte: Avoid setting PG_mte_tagged if no tags cleared or restored Prior to commit 69e3b846d8a7 ("arm64: mte: Sync tags for pages where PTE is untagged"), mte_sync_tags() was only called for pte_tagged() entries (those mapped with PROT_MTE). Therefore mte_sync_tags() could safely use test_and_set_bit(PG_mte_tagged, &page->flags) without inadvertently setting PG_mte_tagged on an untagged page. The above commit was required as guests may enable MTE without any control at the stage 2 mapping, nor a PROT_MTE mapping in the VMM. However, the side-effect was that any page with a PTE that looked like swap (or migration) was getting PG_mte_tagged set automatically. A subsequent page copy (e.g. migration) copied the tags to the destination page even if the tags were owned by KASAN. This issue was masked by the page_kasan_tag_reset() call introduced in commit e5b8d9218951 ("arm64: mte: reset the page tag in page->flags"). When this commit was reverted (20794545c146), KASAN started reporting access faults because the overriding tags in a page did not match the original page->flags (with CONFIG_KASAN_HW_TAGS=y): BUG: KASAN: invalid-access in copy_page+0x10/0xd0 arch/arm64/lib/copy_page.S:26 Read at addr f5ff000017f2e000 by task syz-executor.1/2218 Pointer tag: [f5], memory tag: [f2] Move the PG_mte_tagged bit setting from mte_sync_tags() to the actual place where tags are cleared (mte_sync_page_tags()) or restored (mte_restore_tags()).
Severity ?
No CVSS data available.
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: 69e3b846d8a753f9f279f29531ca56b0f7563ad0 , < 918002bdbe4328c8c0164a22e8ebf2384b80dc23 (git)
Affected: 69e3b846d8a753f9f279f29531ca56b0f7563ad0 , < 749e9fc18b1e1a3f93a9512e91bd7f93002d2821 (git)
Affected: 69e3b846d8a753f9f279f29531ca56b0f7563ad0 , < a8e5e5146ad08d794c58252bab00b261045ef16d (git)
Create a notification for this product.
    Linux Linux Affected: 5.14
Unaffected: 0 , < 5.14 (semver)
Unaffected: 5.15.82 , ≤ 5.15.* (semver)
Unaffected: 6.0.3 , ≤ 6.0.* (semver)
Unaffected: 6.1 , ≤ * (original_commit_for_fix)
Create a notification for this product.
Show details on NVD website
To clipboard 

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "arch/arm64/kernel/mte.c",
            "arch/arm64/mm/mteswap.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "918002bdbe4328c8c0164a22e8ebf2384b80dc23",
              "status": "affected",
              "version": "69e3b846d8a753f9f279f29531ca56b0f7563ad0",
              "versionType": "git"
            },
            {
              "lessThan": "749e9fc18b1e1a3f93a9512e91bd7f93002d2821",
              "status": "affected",
              "version": "69e3b846d8a753f9f279f29531ca56b0f7563ad0",
              "versionType": "git"
            },
            {
              "lessThan": "a8e5e5146ad08d794c58252bab00b261045ef16d",
              "status": "affected",
              "version": "69e3b846d8a753f9f279f29531ca56b0f7563ad0",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "arch/arm64/kernel/mte.c",
            "arch/arm64/mm/mteswap.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.14"
            },
            {
              "lessThan": "5.14",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.82",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.0.*",
              "status": "unaffected",
              "version": "6.0.3",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "6.1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.15.82",
                  "versionStartIncluding": "5.14",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.0.3",
                  "versionStartIncluding": "5.14",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1",
                  "versionStartIncluding": "5.14",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\narm64: mte: Avoid setting PG_mte_tagged if no tags cleared or restored\n\nPrior to commit 69e3b846d8a7 (\"arm64: mte: Sync tags for pages where PTE\nis untagged\"), mte_sync_tags() was only called for pte_tagged() entries\n(those mapped with PROT_MTE). Therefore mte_sync_tags() could safely use\ntest_and_set_bit(PG_mte_tagged, \u0026page-\u003eflags) without inadvertently\nsetting PG_mte_tagged on an untagged page.\n\nThe above commit was required as guests may enable MTE without any\ncontrol at the stage 2 mapping, nor a PROT_MTE mapping in the VMM.\nHowever, the side-effect was that any page with a PTE that looked like\nswap (or migration) was getting PG_mte_tagged set automatically. A\nsubsequent page copy (e.g. migration) copied the tags to the destination\npage even if the tags were owned by KASAN.\n\nThis issue was masked by the page_kasan_tag_reset() call introduced in\ncommit e5b8d9218951 (\"arm64: mte: reset the page tag in page-\u003eflags\").\nWhen this commit was reverted (20794545c146), KASAN started reporting\naccess faults because the overriding tags in a page did not match the\noriginal page-\u003eflags (with CONFIG_KASAN_HW_TAGS=y):\n\n  BUG: KASAN: invalid-access in copy_page+0x10/0xd0 arch/arm64/lib/copy_page.S:26\n  Read at addr f5ff000017f2e000 by task syz-executor.1/2218\n  Pointer tag: [f5], memory tag: [f2]\n\nMove the PG_mte_tagged bit setting from mte_sync_tags() to the actual\nplace where tags are cleared (mte_sync_page_tags()) or restored\n(mte_restore_tags())."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2025-12-09T01:29:27.926Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/918002bdbe4328c8c0164a22e8ebf2384b80dc23"
        },
        {
          "url": "https://git.kernel.org/stable/c/749e9fc18b1e1a3f93a9512e91bd7f93002d2821"
        },
        {
          "url": "https://git.kernel.org/stable/c/a8e5e5146ad08d794c58252bab00b261045ef16d"
        }
      ],
      "title": "arm64: mte: Avoid setting PG_mte_tagged if no tags cleared or restored",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2022-50675",
    "datePublished": "2025-12-09T01:29:27.926Z",
    "dateReserved": "2025-12-09T01:26:45.991Z",
    "dateUpdated": "2025-12-09T01:29:27.926Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Sightings

Author Source Type Date

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



Detection rules are retrieved from Rulezet.