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CVE-2026-97562

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: smb: client: pin DFS superblock in iterator callback tcon_super_cb() stores a raw superblock pointer, but __cifs_get_super() takes its active reference only after iterate_supers_type() has dropped s_umount and its passive reference. Concurrent DFS automount expiry can therefore free the superblock before cifs_sb_active() uses it. A deterministic KASAN test reproduces the race as: BUG: KASAN: slab-use-after-free in cifs_sb_active+0x77/0x80 The same test passes with this change applied. Take the active reference in the callback while iterate_supers_type() still holds s_umount shared. cifs_put_tcp_super() remains the matching release.

Severity
HIGH
CVSS score
7.5 (v3.1)
Vulnerability status
Received
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-09-25 11:17:06.757000
Last modified
2026-10-19 10:17:25.280000
View original CVE JSON
{
  "id": "CVE-2026-97562",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-09-25T11:17:06.757",
  "lastModified": "2026-10-19T10:17:25.280",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: pin DFS superblock in iterator callback\n\ntcon_super_cb() stores a raw superblock pointer, but __cifs_get_super()\ntakes its active reference only after iterate_supers_type() has dropped\ns_umount and its passive reference. Concurrent DFS automount expiry can\ntherefore free the superblock before cifs_sb_active() uses it.\n\nA deterministic KASAN test reproduces the race as:\n\n  BUG: KASAN: slab-use-after-free in cifs_sb_active+0x77/0x80\n\nThe same test passes with this change applied.\n\nTake the active reference in the callback while iterate_supers_type()\nstill holds s_umount shared. cifs_put_tcp_super() remains the matching\nrelease."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "fs/smb/client/misc.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "bacd704a95ad0b93af995aae4a523aa046f46563",
              "lessThan": "3c9acc9835c304013a4faeb969fe9333d66ca9f8",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "bacd704a95ad0b93af995aae4a523aa046f46563",
              "lessThan": "ea43a15cea36dc5ddd832be5bddeac7dd804cbcf",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "bacd704a95ad0b93af995aae4a523aa046f46563",
              "lessThan": "a6b6561522212af852c9ad8a7dca8d59ef2c7377",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "bacd704a95ad0b93af995aae4a523aa046f46563",
              "lessThan": "5b01a8c0209690db75341528ec53fd87e0ac1460",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "bacd704a95ad0b93af995aae4a523aa046f46563",
              "lessThan": "d806d5a85dcbe2a0f181b2f0f9f61ddfbefa1818",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "fs/smb/client/misc.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "5.7",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "5.7",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.6.158",
              "lessThanOrEqual": "6.6.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.12.111",
              "lessThanOrEqual": "6.12.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.53",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2.7",
              "lessThanOrEqual": "7.2.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.3",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H",
          "baseScore": 7.5,
          "baseSeverity": "HIGH",
          "attackVector": "NETWORK",
          "attackComplexity": "HIGH",
          "privilegesRequired": "NONE",
          "userInteraction": "REQUIRED",
          "scope": "UNCHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 1.6,
        "impactScore": 5.9
      }
    ]
  },
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/3c9acc9835c304013a4faeb969fe9333d66ca9f8",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/5b01a8c0209690db75341528ec53fd87e0ac1460",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/a6b6561522212af852c9ad8a7dca8d59ef2c7377",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/d806d5a85dcbe2a0f181b2f0f9f61ddfbefa1818",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/ea43a15cea36dc5ddd832be5bddeac7dd804cbcf",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}