Vulnerability-Lookup

CVE-2026-98360 (GCVE-0-2026-98360)

Vulnerability from cvelistv5 – Published: 2026-10-06 08:46 – Updated: 2026-10-06 08:46

Title

RDMA/rxe: insert mcg into mcg_tree only after rxe_mcast_add() succeeds

Summary

In the Linux kernel, the following vulnerability has been resolved: RDMA/rxe: insert mcg into mcg_tree only after rxe_mcast_add() succeeds rxe_get_mcg() publishes a newly allocated multicast group in rxe->mcg_tree before programming the backing Ethernet multicast address with rxe_mcast_add(), which runs outside mcg_lock. A local userspace RDMA client reaches this path with ATTACH_MCAST on a UD QP; if rxe_mcast_add() then returns an error (for example -ENODEV when the backing netdev has been removed, or a propagated dev_mc_add() error), the unwind frees the published group without removing it from the tree. A later lookup of the same MGID dereferences the freed struct rxe_mcg from __rxe_lookup_mcg(). Fix this by keeping the new mcg private until rxe_mcast_add() succeeds. Split the tree publication into __rxe_publish_mcg(), call rxe_mcast_add() before taking the tree reference, and free the still-private mcg on failure. Because the group is never visible in mcg_tree until the multicast address is programmed, no concurrent caller can look it up or attach a QP to a group that is about to be torn down, so the error path needs no conditional unwind. If another caller publishes the same MGID while the address is being programmed, the post-add re-check under mcg_lock finds the winner; this caller then drops its private object and balances its own rxe_mcast_add() with rxe_mcast_del() before returning the winner. Reproduced by forcing the rxe_mcast_add() error return under KASAN: without the change the next attach to the same MGID reports a slab-use-after-free in __rxe_lookup_mcg(); with it the forced failure returns cleanly. A no-injection attach/detach regression, including a two-QP shared join/leave and re-attach, stays KASAN- and leak-clean.

Severity

No CVSS data available.

Assigner

Linux mitre root Scorecard

References

6 references

URL	Tags
https://git.kernel.org/stable/c/ddb43ac0926d4a931…
https://git.kernel.org/stable/c/c79a789aa15180a15…
https://git.kernel.org/stable/c/faae1fb4ccf820580…
https://git.kernel.org/stable/c/02c0a2fa69c16248a…
https://git.kernel.org/stable/c/d4fc4e37f8a143b0f…
https://git.kernel.org/stable/c/1caceeb2d74bbe882…

Impacted products

2 products

Vendor	Product	Version	CPE status
Linux	Linux	Affected: a926a903b7dc39a8a949150258c09290998dd812 , < ddb43ac0926d4a931bc9b7744b93627f627457e5 (git) Affected: a926a903b7dc39a8a949150258c09290998dd812 , < c79a789aa15180a1543b5db49c343d12e3ec214d (git) Affected: a926a903b7dc39a8a949150258c09290998dd812 , < faae1fb4ccf8205806a8802c008798dabeb0205b (git) Affected: a926a903b7dc39a8a949150258c09290998dd812 , < 02c0a2fa69c16248a7432af8a6d64ab2a73a5283 (git) Affected: a926a903b7dc39a8a949150258c09290998dd812 , < d4fc4e37f8a143b0fe83b42c8fb48cf542154fee (git) Affected: a926a903b7dc39a8a949150258c09290998dd812 , < 1caceeb2d74bbe88223aea55eb8626b4c5f076fd (git)	guessed
Linux	Linux	Affected: 5.18 Unaffected: 0 , < 5.18 (semver) Unaffected: 6.1.189 , ≤ 6.1.* (semver) Unaffected: 6.6.158 , ≤ 6.6.* (semver) Unaffected: 6.12.112 , ≤ 6.12.* (semver) Unaffected: 6.18.54 , ≤ 6.18.* (semver) Unaffected: 7.2.8 , ≤ 7.2.* (semver) Unaffected: 7.3-rc4 , ≤ * (original_commit_for_fix)	guessed

Show details on NVD website

JSON

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/infiniband/sw/rxe/rxe_mcast.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "ddb43ac0926d4a931bc9b7744b93627f627457e5",
              "status": "affected",
              "version": "a926a903b7dc39a8a949150258c09290998dd812",
              "versionType": "git"
            },
            {
              "lessThan": "c79a789aa15180a1543b5db49c343d12e3ec214d",
              "status": "affected",
              "version": "a926a903b7dc39a8a949150258c09290998dd812",
              "versionType": "git"
            },
            {
              "lessThan": "faae1fb4ccf8205806a8802c008798dabeb0205b",
              "status": "affected",
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              "versionType": "git"
            },
            {
              "lessThan": "02c0a2fa69c16248a7432af8a6d64ab2a73a5283",
              "status": "affected",
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              "versionType": "git"
            },
            {
              "lessThan": "d4fc4e37f8a143b0fe83b42c8fb48cf542154fee",
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              "versionType": "git"
            },
            {
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              "status": "affected",
              "version": "a926a903b7dc39a8a949150258c09290998dd812",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/infiniband/sw/rxe/rxe_mcast.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.18"
            },
            {
              "lessThan": "5.18",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.189",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.158",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.112",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.54",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.8",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3-rc4",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1.189",
                  "versionStartIncluding": "5.18",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.158",
                  "versionStartIncluding": "5.18",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.112",
                  "versionStartIncluding": "5.18",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.54",
                  "versionStartIncluding": "5.18",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.8",
                  "versionStartIncluding": "5.18",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3-rc4",
                  "versionStartIncluding": "5.18",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nRDMA/rxe: insert mcg into mcg_tree only after rxe_mcast_add() succeeds\n\nrxe_get_mcg() publishes a newly allocated multicast group in\nrxe-\u003emcg_tree before programming the backing Ethernet multicast address\nwith rxe_mcast_add(), which runs outside mcg_lock. A local userspace\nRDMA client reaches this path with ATTACH_MCAST on a UD QP; if\nrxe_mcast_add() then returns an error (for example -ENODEV when the\nbacking netdev has been removed, or a propagated dev_mc_add() error),\nthe unwind frees the published group without removing it from the tree.\nA later lookup of the same MGID dereferences the freed struct rxe_mcg\nfrom __rxe_lookup_mcg().\n\nFix this by keeping the new mcg private until rxe_mcast_add() succeeds.\nSplit the tree publication into __rxe_publish_mcg(), call rxe_mcast_add()\nbefore taking the tree reference, and free the still-private mcg on\nfailure. Because the group is never visible in mcg_tree until the\nmulticast address is programmed, no concurrent caller can look it up or\nattach a QP to a group that is about to be torn down, so the error path\nneeds no conditional unwind. If another caller publishes the same MGID\nwhile the address is being programmed, the post-add re-check under\nmcg_lock finds the winner; this caller then drops its private object and\nbalances its own rxe_mcast_add() with rxe_mcast_del() before returning\nthe winner.\n\nReproduced by forcing the rxe_mcast_add() error return under KASAN:\nwithout the change the next attach to the same MGID reports a\nslab-use-after-free in __rxe_lookup_mcg(); with it the forced failure\nreturns cleanly. A no-injection attach/detach regression, including a\ntwo-QP shared join/leave and re-attach, stays KASAN- and leak-clean."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-06T08:46:46.743Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/ddb43ac0926d4a931bc9b7744b93627f627457e5"
        },
        {
          "url": "https://git.kernel.org/stable/c/c79a789aa15180a1543b5db49c343d12e3ec214d"
        },
        {
          "url": "https://git.kernel.org/stable/c/faae1fb4ccf8205806a8802c008798dabeb0205b"
        },
        {
          "url": "https://git.kernel.org/stable/c/02c0a2fa69c16248a7432af8a6d64ab2a73a5283"
        },
        {
          "url": "https://git.kernel.org/stable/c/d4fc4e37f8a143b0fe83b42c8fb48cf542154fee"
        },
        {
          "url": "https://git.kernel.org/stable/c/1caceeb2d74bbe88223aea55eb8626b4c5f076fd"
        }
      ],
      "title": "RDMA/rxe: insert mcg into mcg_tree only after rxe_mcast_add() succeeds",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-98360",
    "datePublished": "2026-10-06T08:46:46.743Z",
    "dateReserved": "2026-09-25T10:25:14.344Z",
    "dateUpdated": "2026-10-06T08:46:46.743Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-98360",
      "date": "2026-10-06",
      "epss": "0.00176",
      "percentile": "0.06525"
    },
    "nvd": {
      "cve": {
        "affected": [
          {
            "affectedData": [
              {
                "defaultStatus": "unaffected",
                "product": "Linux",
                "programFiles": [
                  "drivers/infiniband/sw/rxe/rxe_mcast.c"
                ],
                "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                "vendor": "Linux",
                "versions": [
                  {
                    "lessThan": "ddb43ac0926d4a931bc9b7744b93627f627457e5",
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                    "versionType": "git"
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                  {
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                    "versionType": "git"
                  },
                  {
                    "lessThan": "faae1fb4ccf8205806a8802c008798dabeb0205b",
                    "status": "affected",
                    "version": "a926a903b7dc39a8a949150258c09290998dd812",
                    "versionType": "git"
                  },
                  {
                    "lessThan": "02c0a2fa69c16248a7432af8a6d64ab2a73a5283",
                    "status": "affected",
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                    "versionType": "git"
                  },
                  {
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                    "versionType": "git"
                  }
                ]
              },
              {
                "defaultStatus": "affected",
                "product": "Linux",
                "programFiles": [
                  "drivers/infiniband/sw/rxe/rxe_mcast.c"
                ],
                "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                "vendor": "Linux",
                "versions": [
                  {
                    "status": "affected",
                    "version": "5.18"
                  },
                  {
                    "lessThan": "5.18",
                    "status": "unaffected",
                    "version": "0",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "6.1.*",
                    "status": "unaffected",
                    "version": "6.1.189",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "6.6.*",
                    "status": "unaffected",
                    "version": "6.6.158",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "6.12.*",
                    "status": "unaffected",
                    "version": "6.12.112",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "6.18.*",
                    "status": "unaffected",
                    "version": "6.18.54",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "7.2.*",
                    "status": "unaffected",
                    "version": "7.2.8",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "*",
                    "status": "unaffected",
                    "version": "7.3-rc4",
                    "versionType": "original_commit_for_fix"
                  }
                ]
              }
            ],
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
          }
        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nRDMA/rxe: insert mcg into mcg_tree only after rxe_mcast_add() succeeds\n\nrxe_get_mcg() publishes a newly allocated multicast group in\nrxe-\u003emcg_tree before programming the backing Ethernet multicast address\nwith rxe_mcast_add(), which runs outside mcg_lock. A local userspace\nRDMA client reaches this path with ATTACH_MCAST on a UD QP; if\nrxe_mcast_add() then returns an error (for example -ENODEV when the\nbacking netdev has been removed, or a propagated dev_mc_add() error),\nthe unwind frees the published group without removing it from the tree.\nA later lookup of the same MGID dereferences the freed struct rxe_mcg\nfrom __rxe_lookup_mcg().\n\nFix this by keeping the new mcg private until rxe_mcast_add() succeeds.\nSplit the tree publication into __rxe_publish_mcg(), call rxe_mcast_add()\nbefore taking the tree reference, and free the still-private mcg on\nfailure. Because the group is never visible in mcg_tree until the\nmulticast address is programmed, no concurrent caller can look it up or\nattach a QP to a group that is about to be torn down, so the error path\nneeds no conditional unwind. If another caller publishes the same MGID\nwhile the address is being programmed, the post-add re-check under\nmcg_lock finds the winner; this caller then drops its private object and\nbalances its own rxe_mcast_add() with rxe_mcast_del() before returning\nthe winner.\n\nReproduced by forcing the rxe_mcast_add() error return under KASAN:\nwithout the change the next attach to the same MGID reports a\nslab-use-after-free in __rxe_lookup_mcg(); with it the forced failure\nreturns cleanly. A no-injection attach/detach regression, including a\ntwo-QP shared join/leave and re-attach, stays KASAN- and leak-clean."
          }
        ],
        "id": "CVE-2026-98360",
        "lastModified": "2026-10-06T09:18:29.803",
        "metrics": {},
        "published": "2026-10-06T09:18:29.803",
        "references": [
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/02c0a2fa69c16248a7432af8a6d64ab2a73a5283"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/1caceeb2d74bbe88223aea55eb8626b4c5f076fd"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/c79a789aa15180a1543b5db49c343d12e3ec214d"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/d4fc4e37f8a143b0fe83b42c8fb48cf542154fee"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/ddb43ac0926d4a931bc9b7744b93627f627457e5"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/faae1fb4ccf8205806a8802c008798dabeb0205b"
          }
        ],
        "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "vulnStatus": "Received"
      }
    }
  }
}

FKIE_CVE-2026-98360

Vulnerability from fkie_nvd - Published: 2026-10-06 09:18 - Updated: 2026-10-06 09:18

Severity

Summary

References

	URL	Tags
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/02c0a2fa69c16248a7432af8a6d64ab2a73a5283
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/1caceeb2d74bbe88223aea55eb8626b4c5f076fd
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/c79a789aa15180a1543b5db49c343d12e3ec214d
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/d4fc4e37f8a143b0fe83b42c8fb48cf542154fee
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/ddb43ac0926d4a931bc9b7744b93627f627457e5
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/faae1fb4ccf8205806a8802c008798dabeb0205b

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/infiniband/sw/rxe/rxe_mcast.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "ddb43ac0926d4a931bc9b7744b93627f627457e5",
              "status": "affected",
              "version": "a926a903b7dc39a8a949150258c09290998dd812",
              "versionType": "git"
            },
            {
              "lessThan": "c79a789aa15180a1543b5db49c343d12e3ec214d",
              "status": "affected",
              "version": "a926a903b7dc39a8a949150258c09290998dd812",
              "versionType": "git"
            },
            {
              "lessThan": "faae1fb4ccf8205806a8802c008798dabeb0205b",
              "status": "affected",
              "version": "a926a903b7dc39a8a949150258c09290998dd812",
              "versionType": "git"
            },
            {
              "lessThan": "02c0a2fa69c16248a7432af8a6d64ab2a73a5283",
              "status": "affected",
              "version": "a926a903b7dc39a8a949150258c09290998dd812",
              "versionType": "git"
            },
            {
              "lessThan": "d4fc4e37f8a143b0fe83b42c8fb48cf542154fee",
              "status": "affected",
              "version": "a926a903b7dc39a8a949150258c09290998dd812",
              "versionType": "git"
            },
            {
              "lessThan": "1caceeb2d74bbe88223aea55eb8626b4c5f076fd",
              "status": "affected",
              "version": "a926a903b7dc39a8a949150258c09290998dd812",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/infiniband/sw/rxe/rxe_mcast.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.18"
            },
            {
              "lessThan": "5.18",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.189",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.158",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.112",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.54",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.8",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3-rc4",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nRDMA/rxe: insert mcg into mcg_tree only after rxe_mcast_add() succeeds\n\nrxe_get_mcg() publishes a newly allocated multicast group in\nrxe-\u003emcg_tree before programming the backing Ethernet multicast address\nwith rxe_mcast_add(), which runs outside mcg_lock. A local userspace\nRDMA client reaches this path with ATTACH_MCAST on a UD QP; if\nrxe_mcast_add() then returns an error (for example -ENODEV when the\nbacking netdev has been removed, or a propagated dev_mc_add() error),\nthe unwind frees the published group without removing it from the tree.\nA later lookup of the same MGID dereferences the freed struct rxe_mcg\nfrom __rxe_lookup_mcg().\n\nFix this by keeping the new mcg private until rxe_mcast_add() succeeds.\nSplit the tree publication into __rxe_publish_mcg(), call rxe_mcast_add()\nbefore taking the tree reference, and free the still-private mcg on\nfailure. Because the group is never visible in mcg_tree until the\nmulticast address is programmed, no concurrent caller can look it up or\nattach a QP to a group that is about to be torn down, so the error path\nneeds no conditional unwind. If another caller publishes the same MGID\nwhile the address is being programmed, the post-add re-check under\nmcg_lock finds the winner; this caller then drops its private object and\nbalances its own rxe_mcast_add() with rxe_mcast_del() before returning\nthe winner.\n\nReproduced by forcing the rxe_mcast_add() error return under KASAN:\nwithout the change the next attach to the same MGID reports a\nslab-use-after-free in __rxe_lookup_mcg(); with it the forced failure\nreturns cleanly. A no-injection attach/detach regression, including a\ntwo-QP shared join/leave and re-attach, stays KASAN- and leak-clean."
    }
  ],
  "id": "CVE-2026-98360",
  "lastModified": "2026-10-06T09:18:29.803",
  "metrics": {},
  "published": "2026-10-06T09:18:29.803",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/02c0a2fa69c16248a7432af8a6d64ab2a73a5283"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/1caceeb2d74bbe88223aea55eb8626b4c5f076fd"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/c79a789aa15180a1543b5db49c343d12e3ec214d"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/d4fc4e37f8a143b0fe83b42c8fb48cf542154fee"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/ddb43ac0926d4a931bc9b7744b93627f627457e5"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/faae1fb4ccf8205806a8802c008798dabeb0205b"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}

GHSA-2MRF-76X9-2X42

Vulnerability from github – Published: 2026-10-06 09:31 – Updated: 2026-10-06 09:31

Details

In the Linux kernel, the following vulnerability has been resolved:

RDMA/rxe: insert mcg into mcg_tree only after rxe_mcast_add() succeeds

rxe_get_mcg() publishes a newly allocated multicast group in rxe->mcg_tree before programming the backing Ethernet multicast address with rxe_mcast_add(), which runs outside mcg_lock. A local userspace RDMA client reaches this path with ATTACH_MCAST on a UD QP; if rxe_mcast_add() then returns an error (for example -ENODEV when the backing netdev has been removed, or a propagated dev_mc_add() error), the unwind frees the published group without removing it from the tree. A later lookup of the same MGID dereferences the freed struct rxe_mcg from __rxe_lookup_mcg().

Fix this by keeping the new mcg private until rxe_mcast_add() succeeds. Split the tree publication into __rxe_publish_mcg(), call rxe_mcast_add() before taking the tree reference, and free the still-private mcg on failure. Because the group is never visible in mcg_tree until the multicast address is programmed, no concurrent caller can look it up or attach a QP to a group that is about to be torn down, so the error path needs no conditional unwind. If another caller publishes the same MGID while the address is being programmed, the post-add re-check under mcg_lock finds the winner; this caller then drops its private object and balances its own rxe_mcast_add() with rxe_mcast_del() before returning the winner.

Reproduced by forcing the rxe_mcast_add() error return under KASAN: without the change the next attach to the same MGID reports a slab-use-after-free in __rxe_lookup_mcg(); with it the forced failure returns cleanly. A no-injection attach/detach regression, including a two-QP shared join/leave and re-attach, stays KASAN- and leak-clean.

Show details on source website

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{
  "affected": [],
  "aliases": [
    "CVE-2026-98360"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-10-06T09:18:29Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nRDMA/rxe: insert mcg into mcg_tree only after rxe_mcast_add() succeeds\n\nrxe_get_mcg() publishes a newly allocated multicast group in\nrxe-\u003emcg_tree before programming the backing Ethernet multicast address\nwith rxe_mcast_add(), which runs outside mcg_lock. A local userspace\nRDMA client reaches this path with ATTACH_MCAST on a UD QP; if\nrxe_mcast_add() then returns an error (for example -ENODEV when the\nbacking netdev has been removed, or a propagated dev_mc_add() error),\nthe unwind frees the published group without removing it from the tree.\nA later lookup of the same MGID dereferences the freed struct rxe_mcg\nfrom __rxe_lookup_mcg().\n\nFix this by keeping the new mcg private until rxe_mcast_add() succeeds.\nSplit the tree publication into __rxe_publish_mcg(), call rxe_mcast_add()\nbefore taking the tree reference, and free the still-private mcg on\nfailure. Because the group is never visible in mcg_tree until the\nmulticast address is programmed, no concurrent caller can look it up or\nattach a QP to a group that is about to be torn down, so the error path\nneeds no conditional unwind. If another caller publishes the same MGID\nwhile the address is being programmed, the post-add re-check under\nmcg_lock finds the winner; this caller then drops its private object and\nbalances its own rxe_mcast_add() with rxe_mcast_del() before returning\nthe winner.\n\nReproduced by forcing the rxe_mcast_add() error return under KASAN:\nwithout the change the next attach to the same MGID reports a\nslab-use-after-free in __rxe_lookup_mcg(); with it the forced failure\nreturns cleanly. A no-injection attach/detach regression, including a\ntwo-QP shared join/leave and re-attach, stays KASAN- and leak-clean.",
  "id": "GHSA-2mrf-76x9-2x42",
  "modified": "2026-10-06T09:31:36Z",
  "published": "2026-10-06T09:31:36Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-98360"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/02c0a2fa69c16248a7432af8a6d64ab2a73a5283"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/1caceeb2d74bbe88223aea55eb8626b4c5f076fd"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c79a789aa15180a1543b5db49c343d12e3ec214d"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d4fc4e37f8a143b0fe83b42c8fb48cf542154fee"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ddb43ac0926d4a931bc9b7744b93627f627457e5"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/faae1fb4ccf8205806a8802c008798dabeb0205b"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

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The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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Action not permitted

CVE-2026-98360 (GCVE-0-2026-98360)

FKIE_CVE-2026-98360

GHSA-2MRF-76X9-2X42

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