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vxlan: mdb: Fix use-after-free in vxlan_mdb_remote_src_del()

Type: advisorySource: Official CVE List1 source record

In the Linux kernel, the following vulnerability has been resolved: vxlan: mdb: Fix use-after-free in vxlan_mdb_remote_src_del() vxlan_mdb_is_valid_source(), which validates MDBE_ATTR_SOURCE and every MDBE_ATTR_SRC_LIST member, accepts the all-zeros address. A source list is only accepted on a (*, G) entry, whose source is the all-zeros address, and for each member of the list an (S, G) entry is derived from it by substituting the source. Entries are keyed by a plain memcmp() of struct vxlan_mdb_entry_key, so if MDBE_ATTR_SOURCE is present and holds the all-zeros address and the source list holds it as well, the derived (S, G) key is byte-identical to the (*, G) key and resolves to the same entry. Omitting MDBE_ATTR_SOURCE is not equivalent, as the key is then left with a zero address family. vxlan_mdb_remote_src_del() removes the forwarding entry of a source before freeing the source entry: vxlan_mdb_remote_src_fwd_del(vxlan, group, remote, &ent->addr); vxlan_mdb_remote_src_entry_del(ent); With the keys aliased, the first call deletes the remote of the entry that owns 'ent' instead of a separate (S, G) entry, and frees 'ent'. The second call then runs on the freed entry, and its hlist_del() reads ->pprev and ->next out of it and writes through them. Adding the (*, G) entry with NLM_F_REPLACE and no source list marks the all-zeros source for deletion and reaches this from the sweep at the end of vxlan_mdb_remote_srcs_replace(). BUG: KASAN: slab-use-after-free in __vxlan_mdb_a

Announced Source revision 1
Original source ↗

CVE-2026-98122

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-2026-98122

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": "a3a48de5eade770e911d35291217bdd69ce04ef1",
        "lessThan": "069d5527bb0f229e528fa88c6b72f15060c373f2",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "a3a48de5eade770e911d35291217bdd69ce04ef1",
        "lessThan": "e12c903fd13c6261b98ca18d8f70ac26e739e2f8",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "a3a48de5eade770e911d35291217bdd69ce04ef1",
        "lessThan": "74e2a56c82209b0335b53e25f19f9b0590e2483d",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "a3a48de5eade770e911d35291217bdd69ce04ef1",
        "lessThan": "71203a41d6fa2fa0ea2f3a7541987958bd3694fd",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "a3a48de5eade770e911d35291217bdd69ce04ef1",
        "lessThan": "4aa61c88b4e292e10abdfd791334b8272108d68a",
        "versionType": "git"
      }
    ],
    "programFiles": [
      "drivers/net/vxlan/vxlan_mdb.c",
      "tools/testing/selftests/net/test_vxlan_mdb.sh"
    ],
    "defaultStatus": "unaffected"
  },
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "6.4"
      },
      {
        "status": "unaffected",
        "version": "0",
        "lessThan": "6.4",
        "versionType": "semver"
      },
      {
        "status": "unaffected",
        "version": "6.6.158",
        "versionType": "semver",
        "lessThanOrEqual": "6.6.*"
      },
      {
        "status": "unaffected",
        "version": "6.12.111",
        "versionType": "semver",
        "lessThanOrEqual": "6.12.*"
      },
      {
        "status": "unaffected",
        "version": "6.18.53",
        "versionType": "semver",
        "lessThanOrEqual": "6.18.*"
      },
      {
        "status": "unaffected",
        "version": "7.2.7",
        "versionType": "semver",
        "lessThanOrEqual": "7.2.*"
      },
      {
        "status": "unaffected",
        "version": "7.3",
        "versionType": "original_commit_for_fix",
        "lessThanOrEqual": "*"
      }
    ],
    "programFiles": [
      "drivers/net/vxlan/vxlan_mdb.c",
      "tools/testing/selftests/net/test_vxlan_mdb.sh"
    ],
    "defaultStatus": "affected"
  }
]
Related CVEs
CVE-2026-98122

Source reference: /cveMetadata/cveId

Publisher severity

high

Source reference: /containers/cna/metrics

Event
#38220 · Revision 1
Added to Heist Feed
Publisher date
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