CVE-2026-89950

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: batman-adv: mcast: linearize skbuff for packet generation batadv_mcast_forw_packet() and batadv_mcast_forw_scrape() is not only called (indirectly) by the unsharing+linearizing batadv_recv_mcast_packet() handler. When it is called (indirectly) by batadv_mcast_forw_mcsend() then it will be unshared but not linearized. The SKB_LINEAR_ASSERT() can therefore cause a fatal BUG(). The linearization should happen during the expansion of the head because the scrape function can be hit already during the initial batadv_mcast_forw_mode() selection code: * batadv_interface_tx * batadv_mcast_forw_mode * batadv_mcast_forw_mode_by_count() * batadv_mcast_forw_push() -> calls batadv_mcast_forw_expand_head() before everything else * batadv_mcast_forw_push_tvlvs() * batadv_mcast_forw_push_dests() * batadv_mcast_forw_push_adjust_padding() * batadv_mcast_forw_scrape()

Severity

Not scored

CVSS score

Not available

Vulnerability status

Received

Source identifier

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

Published

2026-09-16 11:17:05.160000

Last modified

2026-10-19 09:18:41.010000

View original CVE JSON

{
  "id": "CVE-2026-89950",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-09-16T11:17:05.160",
  "lastModified": "2026-10-19T09:18:41.010",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbatman-adv: mcast: linearize skbuff for packet generation\n\nbatadv_mcast_forw_packet() and batadv_mcast_forw_scrape() is not only\ncalled (indirectly) by the unsharing+linearizing batadv_recv_mcast_packet()\nhandler. When it is called (indirectly) by batadv_mcast_forw_mcsend() then\nit will be unshared but not linearized. The SKB_LINEAR_ASSERT() can\ntherefore cause a fatal BUG().\n\nThe linearization should happen during the expansion of the head because\nthe scrape function can be hit already during the initial\nbatadv_mcast_forw_mode() selection code:\n\n* batadv_interface_tx\n* batadv_mcast_forw_mode\n* batadv_mcast_forw_mode_by_count()\n* batadv_mcast_forw_push()\n  -> calls batadv_mcast_forw_expand_head() before everything else\n* batadv_mcast_forw_push_tvlvs()\n* batadv_mcast_forw_push_dests()\n* batadv_mcast_forw_push_adjust_padding()\n* batadv_mcast_forw_scrape()"
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "net/batman-adv/multicast_forw.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "90039133221e33964ccb4a536dad7eb0a372fff7",
              "lessThan": "a9603e0a7cb5e0cddc6b23af153cf7daafc5c55e",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "90039133221e33964ccb4a536dad7eb0a372fff7",
              "lessThan": "c32e5e25c41201c8c3b796a4ab2c45103187091e",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "90039133221e33964ccb4a536dad7eb0a372fff7",
              "lessThan": "2879177539e3ece483a8e5406970373698e9a6c5",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "90039133221e33964ccb4a536dad7eb0a372fff7",
              "lessThan": "6a30a59e2660afd03c975f1b8eae6a2301161197",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "net/batman-adv/multicast_forw.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "6.8",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "6.8",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.12.110",
              "lessThanOrEqual": "6.12.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.51",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2.5",
              "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/2879177539e3ece483a8e5406970373698e9a6c5",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/6a30a59e2660afd03c975f1b8eae6a2301161197",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/a9603e0a7cb5e0cddc6b23af153cf7daafc5c55e",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/c32e5e25c41201c8c3b796a4ab2c45103187091e",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}