CVE-2024-56751 (GCVE-0-2024-56751)

Vulnerability from cvelistv5 – Published: 2024-12-29 11:30 – Updated: 2025-11-03 20:53
VLAI?
Title
ipv6: release nexthop on device removal
Summary
In the Linux kernel, the following vulnerability has been resolved: ipv6: release nexthop on device removal The CI is hitting some aperiodic hangup at device removal time in the pmtu.sh self-test: unregister_netdevice: waiting for veth_A-R1 to become free. Usage count = 6 ref_tracker: veth_A-R1@ffff888013df15d8 has 1/5 users at dst_init+0x84/0x4a0 dst_alloc+0x97/0x150 ip6_dst_alloc+0x23/0x90 ip6_rt_pcpu_alloc+0x1e6/0x520 ip6_pol_route+0x56f/0x840 fib6_rule_lookup+0x334/0x630 ip6_route_output_flags+0x259/0x480 ip6_dst_lookup_tail.constprop.0+0x5c2/0x940 ip6_dst_lookup_flow+0x88/0x190 udp_tunnel6_dst_lookup+0x2a7/0x4c0 vxlan_xmit_one+0xbde/0x4a50 [vxlan] vxlan_xmit+0x9ad/0xf20 [vxlan] dev_hard_start_xmit+0x10e/0x360 __dev_queue_xmit+0xf95/0x18c0 arp_solicit+0x4a2/0xe00 neigh_probe+0xaa/0xf0 While the first suspect is the dst_cache, explicitly tracking the dst owing the last device reference via probes proved such dst is held by the nexthop in the originating fib6_info. Similar to commit f5b51fe804ec ("ipv6: route: purge exception on removal"), we need to explicitly release the originating fib info when disconnecting a to-be-removed device from a live ipv6 dst: move the fib6_info cleanup into ip6_dst_ifdown(). Tested running: ./pmtu.sh cleanup_ipv6_exception in a tight loop for more than 400 iterations with no spat, running an unpatched kernel I observed a splat every ~10 iterations.
Severity ?
No CVSS data available.
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: f88d8ea67fbdbac7a64bfa6ed9a2ba27bb822f74 , < 77aa9855a878fb43f547ddfbda3127a1e88ad31a (git)
Affected: f88d8ea67fbdbac7a64bfa6ed9a2ba27bb822f74 , < b2f26a27ea3f72f75d18330f76f5d1007c791848 (git)
Affected: f88d8ea67fbdbac7a64bfa6ed9a2ba27bb822f74 , < 43e25adc80269f917d2a195f0d59f74cdd182955 (git)
Affected: f88d8ea67fbdbac7a64bfa6ed9a2ba27bb822f74 , < a3c3f8a4d025acc8c857246ec2b812c59102487a (git)
Affected: f88d8ea67fbdbac7a64bfa6ed9a2ba27bb822f74 , < 0e4c6faaef8a24b762a24ffb767280e263ef8e10 (git)
Affected: f88d8ea67fbdbac7a64bfa6ed9a2ba27bb822f74 , < eb02688c5c45c3e7af7e71f036a7144f5639cbfe (git)
Create a notification for this product.
    Linux Linux Affected: 5.3
Unaffected: 0 , < 5.3 (semver)
Unaffected: 5.15.181 , ≤ 5.15.* (semver)
Unaffected: 6.1.120 , ≤ 6.1.* (semver)
Unaffected: 6.6.64 , ≤ 6.6.* (semver)
Unaffected: 6.11.11 , ≤ 6.11.* (semver)
Unaffected: 6.12.2 , ≤ 6.12.* (semver)
Unaffected: 6.13 , ≤ * (original_commit_for_fix)
Create a notification for this product.
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2025-11-03T20:53:42.799Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "url": "https://lists.debian.org/debian-lts-announce/2025/03/msg00001.html"
          }
        ],
        "title": "CVE Program Container"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/ipv6/route.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "77aa9855a878fb43f547ddfbda3127a1e88ad31a",
              "status": "affected",
              "version": "f88d8ea67fbdbac7a64bfa6ed9a2ba27bb822f74",
              "versionType": "git"
            },
            {
              "lessThan": "b2f26a27ea3f72f75d18330f76f5d1007c791848",
              "status": "affected",
              "version": "f88d8ea67fbdbac7a64bfa6ed9a2ba27bb822f74",
              "versionType": "git"
            },
            {
              "lessThan": "43e25adc80269f917d2a195f0d59f74cdd182955",
              "status": "affected",
              "version": "f88d8ea67fbdbac7a64bfa6ed9a2ba27bb822f74",
              "versionType": "git"
            },
            {
              "lessThan": "a3c3f8a4d025acc8c857246ec2b812c59102487a",
              "status": "affected",
              "version": "f88d8ea67fbdbac7a64bfa6ed9a2ba27bb822f74",
              "versionType": "git"
            },
            {
              "lessThan": "0e4c6faaef8a24b762a24ffb767280e263ef8e10",
              "status": "affected",
              "version": "f88d8ea67fbdbac7a64bfa6ed9a2ba27bb822f74",
              "versionType": "git"
            },
            {
              "lessThan": "eb02688c5c45c3e7af7e71f036a7144f5639cbfe",
              "status": "affected",
              "version": "f88d8ea67fbdbac7a64bfa6ed9a2ba27bb822f74",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/ipv6/route.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.3"
            },
            {
              "lessThan": "5.3",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.181",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.120",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.64",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.11.*",
              "status": "unaffected",
              "version": "6.11.11",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.2",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "6.13",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.15.181",
                  "versionStartIncluding": "5.3",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1.120",
                  "versionStartIncluding": "5.3",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.64",
                  "versionStartIncluding": "5.3",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.11.11",
                  "versionStartIncluding": "5.3",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.2",
                  "versionStartIncluding": "5.3",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.13",
                  "versionStartIncluding": "5.3",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: release nexthop on device removal\n\nThe CI is hitting some aperiodic hangup at device removal time in the\npmtu.sh self-test:\n\nunregister_netdevice: waiting for veth_A-R1 to become free. Usage count = 6\nref_tracker: veth_A-R1@ffff888013df15d8 has 1/5 users at\n\tdst_init+0x84/0x4a0\n\tdst_alloc+0x97/0x150\n\tip6_dst_alloc+0x23/0x90\n\tip6_rt_pcpu_alloc+0x1e6/0x520\n\tip6_pol_route+0x56f/0x840\n\tfib6_rule_lookup+0x334/0x630\n\tip6_route_output_flags+0x259/0x480\n\tip6_dst_lookup_tail.constprop.0+0x5c2/0x940\n\tip6_dst_lookup_flow+0x88/0x190\n\tudp_tunnel6_dst_lookup+0x2a7/0x4c0\n\tvxlan_xmit_one+0xbde/0x4a50 [vxlan]\n\tvxlan_xmit+0x9ad/0xf20 [vxlan]\n\tdev_hard_start_xmit+0x10e/0x360\n\t__dev_queue_xmit+0xf95/0x18c0\n\tarp_solicit+0x4a2/0xe00\n\tneigh_probe+0xaa/0xf0\n\nWhile the first suspect is the dst_cache, explicitly tracking the dst\nowing the last device reference via probes proved such dst is held by\nthe nexthop in the originating fib6_info.\n\nSimilar to commit f5b51fe804ec (\"ipv6: route: purge exception on\nremoval\"), we need to explicitly release the originating fib info when\ndisconnecting a to-be-removed device from a live ipv6 dst: move the\nfib6_info cleanup into ip6_dst_ifdown().\n\nTested running:\n\n./pmtu.sh cleanup_ipv6_exception\n\nin a tight loop for more than 400 iterations with no spat, running an\nunpatched kernel  I observed a splat every ~10 iterations."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2025-05-04T10:03:52.312Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/77aa9855a878fb43f547ddfbda3127a1e88ad31a"
        },
        {
          "url": "https://git.kernel.org/stable/c/b2f26a27ea3f72f75d18330f76f5d1007c791848"
        },
        {
          "url": "https://git.kernel.org/stable/c/43e25adc80269f917d2a195f0d59f74cdd182955"
        },
        {
          "url": "https://git.kernel.org/stable/c/a3c3f8a4d025acc8c857246ec2b812c59102487a"
        },
        {
          "url": "https://git.kernel.org/stable/c/0e4c6faaef8a24b762a24ffb767280e263ef8e10"
        },
        {
          "url": "https://git.kernel.org/stable/c/eb02688c5c45c3e7af7e71f036a7144f5639cbfe"
        }
      ],
      "title": "ipv6: release nexthop on device removal",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2024-56751",
    "datePublished": "2024-12-29T11:30:16.805Z",
    "dateReserved": "2024-12-29T11:26:39.759Z",
    "dateUpdated": "2025-11-03T20:53:42.799Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Sightings

Author Source Type Date

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



Detection rules are retrieved from Rulezet.