CVE-2026-99211

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: netlink: reset skb headers before unicast and multicast filtering Socket filters can use SKF_NET_OFF and SKF_LL_OFF to read relative to an skb's network and MAC headers. Netlink producers may reserve headroom without resetting those headers, allowing a receiving socket's filter to read data before the initialized message. For example, IWPM HELLO replies are allocated with dev_alloc_skb(), which reserves NET_SKB_PAD bytes. An unprivileged NETLINK_RDMA user can attach a classic socket filter and disclose this headroom through the length of the delivered reply. The resets in netlink_dump() do not help because IWPM sends a separately allocated skb through netlink_unicast(). Reset both headers before running the receiver's filter in unicast and broadcast delivery, as is already done for dump skbs. This also covers other netlink producers that reserve headroom without changing their allocation or message-building code.

Severity

Not scored

CVSS score

Not available

Vulnerability status

Received

Source identifier

416baaa9-dc9f-4396-8d5f-8c081fb06d67

Published

2026-10-28 11:17:42.533000

Last modified

2026-10-28 11:17:42.533000

View original CVE JSON

{
  "id": "CVE-2026-99211",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-10-28T11:17:42.533",
  "lastModified": "2026-10-28T11:17:42.533",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetlink: reset skb headers before unicast and multicast filtering\n\nSocket filters can use SKF_NET_OFF and SKF_LL_OFF to read relative to\nan skb's network and MAC headers. Netlink producers may reserve\nheadroom without resetting those headers, allowing a receiving socket's\nfilter to read data before the initialized message.\n\nFor example, IWPM HELLO replies are allocated with dev_alloc_skb(),\nwhich reserves NET_SKB_PAD bytes. An unprivileged NETLINK_RDMA user can\nattach a classic socket filter and disclose this headroom through the\nlength of the delivered reply. The resets in netlink_dump() do not help\nbecause IWPM sends a separately allocated skb through netlink_unicast().\n\nReset both headers before running the receiver's filter in unicast and\nbroadcast delivery, as is already done for dump skbs. This also covers\nother netlink producers that reserve headroom without changing their\nallocation or message-building code."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "net/netlink/af_netlink.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "b1153f29ee07dc1a788964409255a4b4fae50b98",
              "lessThan": "06791594274f87c29f1a9f1961d700272716a49d",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "b1153f29ee07dc1a788964409255a4b4fae50b98",
              "lessThan": "06935da5de83aa8b98841563894857e7d2f80e47",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "b1153f29ee07dc1a788964409255a4b4fae50b98",
              "lessThan": "8bf659bd54e1f00e34cf5244b1d289c506fa47c0",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "net/netlink/af_netlink.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "2.6.26",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "2.6.26",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.59",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2.13",
              "lessThanOrEqual": "7.2.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.3",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {},
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/06791594274f87c29f1a9f1961d700272716a49d",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/06935da5de83aa8b98841563894857e7d2f80e47",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/8bf659bd54e1f00e34cf5244b1d289c506fa47c0",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}