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net/sched: cls_u32: fix manual hash table handle IDR aliasing

Type: advisorySource: Official CVE List1 source record

In the Linux kernel, the following vulnerability has been resolved: net/sched: cls_u32: fix manual hash table handle IDR aliasing A u32 hash table created with an explicit handle ('tc filter add ... handle 801: u32 divisor N') keys its IDR entry on the raw handle, while the destroy paths free it under handle2id(handle). The two key domains disagree for handles in the 0x800..0xFFF htid range: handle2id() folds them back into the auto-allocated id space (1..0x7FF). A manual table therefore leaves its raw-keyed IDR entry unreachable on delete (a permanent leak), and its delete can drop the idr entry of an unrelated live auto table. A later auto allocation can then hand out a handle that aliases the live manual table; u32_lookup_ht() first-match routes lookups and TCA_U32_LINK for that htid to the wrong table. Key the divisor-path alloc on handle2id(handle) so allocation and removal share one key domain. A manual handle that maps onto an id already in use is rejected with -ENOSPC, and auto allocation skips ids held by live manual tables. Conditions to recreate: ip link add test0 type dummy tc qdisc add dev test0 clsact tc filter add dev test0 ingress protocol ip pref 1 \ handle 801: u32 divisor 16 tc filter add dev test0 ingress protocol ip pref 2 u32 divisor 16 tc -d filter show dev test0 ingress | grep 'fh 801:' # unpatched: two live tables with handle 0x80100000 (the pref 2 root # hnode is auto-allocated id 1); patched: the auto hnode takes id 2. Also tested with a poc with a

Announced Source revision 1
Original source ↗

CVE-2026-98629

Primary source · Revision 1

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2026-98629

Linux

Source reference: /containers/cna/affected/0/product

Affected versions
Not stated in this record
Fixed versions
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Prerequisites
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Linux

Source reference: /containers/cna/affected/1/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Structured affected-version data

Original package identities and version rules from this source.

[
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "9b2c3184e126b941dfa716b8128ed6db92a64e2f",
        "lessThan": "21fc07924e996e1e661268ca269c86b8d59d25b3",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "789f9963bd031c3a185605665b744912df8e7eda",
        "lessThan": "0fac292d93fdb313099e98cce928b3a524c92c94",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "73af53d82076bbe184d9ece9e14b0dc8599e6055",
        "lessThan": "54a454c5e41f5e2cb70c8163140ce095c5d5eefd",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "73af53d82076bbe184d9ece9e14b0dc8599e6055",
        "lessThan": "f6696481eedfd5752b4b56eed715d0b0fe48b9c5",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "73af53d82076bbe184d9ece9e14b0dc8599e6055",
        "lessThan": "2f898f9ec7c73c5697ee462681e7ea6984ee1f3d",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "73af53d82076bbe184d9ece9e14b0dc8599e6055",
        "lessThan": "0a5f5d9e94dead312d32c366b917c64e552b72f7",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "4403f9293ce9ecc2a55c688d84ee37e3ba0fc1a8",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "6.1.119",
        "lessThan": "6.1.189",
        "versionType": "semver"
      },
      {
        "status": "affected",
        "version": "6.6.63",
        "lessThan": "6.6.158",
        "versionType": "semver"
      },
      {
        "status": "affected",
        "version": "6.11.10",
        "lessThan": "6.12",
        "versionType": "semver"
      }
    ],
    "programFiles": [
      "net/sched/cls_u32.c"
    ],
    "defaultStatus": "unaffected"
  },
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "6.12"
      },
      {
        "status": "unaffected",
        "version": "0",
        "lessThan": "6.12",
        "versionType": "semver"
      },
      {
        "status": "unaffected",
        "version": "6.1.189",
        "versionType": "semver",
        "lessThanOrEqual": "6.1.*"
      },
      {
        "status": "unaffected",
        "version": "6.6.158",
        "versionType": "semver",
        "lessThanOrEqual": "6.6.*"
      },
      {
        "status": "unaffected",
        "version": "6.12.112",
        "versionType": "semver",
        "lessThanOrEqual": "6.12.*"
      },
      {
        "status": "unaffected",
        "version": "6.18.55",
        "versionType": "semver",
        "lessThanOrEqual": "6.18.*"
      },
      {
        "status": "unaffected",
        "version": "7.2.9",
        "versionType": "semver",
        "lessThanOrEqual": "7.2.*"
      },
      {
        "status": "unaffected",
        "version": "7.3",
        "versionType": "original_commit_for_fix",
        "lessThanOrEqual": "*"
      }
    ],
    "programFiles": [
      "net/sched/cls_u32.c"
    ],
    "defaultStatus": "affected"
  }
]
Related CVEs
CVE-2026-98629

Source reference: /cveMetadata/cveId

Publisher severity

No explicit severity was provided.

Event
#38649 · Revision 1
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