netfs: Fix read abandonment during retry

{
  "id": "5fbcee1adf47caebeac3a883baf6651f28c23fe32310567c1b07656789d7530b",
  "url": "https://osv.dev/vulnerability/CVE-2026-31435",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "netfs: Fix read abandonment during retry",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: netfs: Fix read abandonment during retry Under certain circumstances, all the remaining subrequests from a read request will get abandoned during retry. The abandonment process expects the 'subreq' variable to be set to the place to start abandonment from, but it doesn't always have a useful value (it will be uninitialised on the first pass through the loop and it may point to a deleted subrequest on later passes). Fix the first jump to \"abandon:\" to set subreq to the start of the first subrequest expected to need retry (which, in this abandonment case, turned out unexpectedly to no longer have NEED_RETRY set). Also clear the subreq pointer after discarding superfluous retryable subrequests to cause an oops if we do try to access it.",
    "evidence": "osv:CVE-2026-31435",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.18.21",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.19.11",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-31435",
      "aliases": [
        "CVE-2026-31435"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
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                },
                {
                  "fixed": "3e5fd8f53b575ff2188f82071da19c977ca56c41"
                },
                {
                  "fixed": "8f2f2bd128a8d9edbc1e785760da54ada3df69b7"
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                {
                  "fixed": "7e57523490cd2efb52b1ea97f2e0a74c0fb634cd"
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          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-31435.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.12.0"
                },
                {
                  "fixed": "6.18.21"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.19.0"
                },
                {
                  "fixed": "6.19.11"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-31435.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:34.784112535Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/3e5fd8f53b575ff2188f82071da19c977ca56c41",
        "https://git.kernel.org/stable/c/7e57523490cd2efb52b1ea97f2e0a74c0fb634cd",
        "https://git.kernel.org/stable/c/8f2f2bd128a8d9edbc1e785760da54ada3df69b7",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31435.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-31435",
        "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
      ],
      "provider_metadata": {
        "cna_assigner": "Linux",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31435.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-31435",
        "evidence": "/id"
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    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 502114,
  "published_at": "2026-04-22T13:53:35.032+00:00"
}