CVE-2026-74560 (GCVE-0-2026-74560)

Vulnerability from cvelistv5 – Published: 2026-08-15 12:28 – Updated: 2026-08-17 05:21
VLAI
Title
xsk: fix buffer leak in xsk_drop_skb() for AF_XDP multi-buffer Tx
Summary
In the Linux kernel, the following vulnerability has been resolved: xsk: fix buffer leak in xsk_drop_skb() for AF_XDP multi-buffer Tx This patch is inspired by the check[1] from sashiko. It says when overflow happens, the address of cq to be published is invalid. Actually the severer thing is the whole process of publishing the address of cq in this particular case is not right: it should truely publish the address and advance the cached_prod in cq as long as it reads descriptors from txq. The following is the full analysis. xsk_drop_skb() is called in three places, which all discard a partially built multi-buffer skb: 1) xsk_build_skb() -EOVERFLOW error path: packet exceeds MAX_SKB_FRAGS 2) __xsk_generic_xmit() post-loop cleanup: an invalid descriptor in the TX ring prevents the partial packet from completing 3) xsk_release(): socket close while xs->skb holds an incomplete packet In all three cases, the TX descriptors for the already-processed frags have been consumed from the TX ring (xskq_cons_release), and CQ slots have been reserved. However, xsk_drop_skb() calls xsk_consume_skb() which cancels the CQ reservations via xsk_cq_cancel_locked(). Since the buffer addresses never appear in the completion queue, userspace permanently loses track of these buffers. Fix this by letting consume_skb() trigger the existing xsk_destruct_skb destructor, which already submits buffer addresses to the CQ via xsk_cq_submit_addr_locked(). Note that cancelling the descriptors back to the TX ring (via xskq_cons_cancel_n) is not a appropriate option because an oversized packet that always exceeds MAX_SKB_FRAGS would be retried indefinitely, which is an obviously deadlock bug in the TX path. Also move the desc->addr assignment in xsk_build_skb() above the overflow check so that the current descriptor's address is recorded before a potential -EOVERFLOW jump to free_err, consistent with the zerocopy path in xsk_build_skb_zerocopy(). [1]: https://lore.kernel.org/all/20260425041726.85FB3C2BCB2@smtp.kernel.org/
Severity
No CVSS data available.
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: cf24f5a5feeaae34c1a34d1e04f8ac697290427a , < 05e283466b86e0b25a5209a3eafe87aa9886064a (git)
Affected: cf24f5a5feeaae34c1a34d1e04f8ac697290427a , < a0528ab6af62bf57153caaf8ea28e5fcb0e18fd4 (git)
Affected: cf24f5a5feeaae34c1a34d1e04f8ac697290427a , < a3c8382ebce4780c6b3ace2c09bc342313ac0186 (git)
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Linux Linux Affected: 6.6
Unaffected: 0 , < 6.6 (semver)
Unaffected: 6.18.44 , ≤ 6.18.* (semver)
Unaffected: 7.1.8 , ≤ 7.1.* (semver)
Unaffected: 7.2 , ≤ * (original_commit_for_fix)
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/xdp/xsk.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
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              "lessThan": "05e283466b86e0b25a5209a3eafe87aa9886064a",
              "status": "affected",
              "version": "cf24f5a5feeaae34c1a34d1e04f8ac697290427a",
              "versionType": "git"
            },
            {
              "lessThan": "a0528ab6af62bf57153caaf8ea28e5fcb0e18fd4",
              "status": "affected",
              "version": "cf24f5a5feeaae34c1a34d1e04f8ac697290427a",
              "versionType": "git"
            },
            {
              "lessThan": "a3c8382ebce4780c6b3ace2c09bc342313ac0186",
              "status": "affected",
              "version": "cf24f5a5feeaae34c1a34d1e04f8ac697290427a",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/xdp/xsk.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.6"
            },
            {
              "lessThan": "6.6",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.44",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.8",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.44",
                  "versionStartIncluding": "6.6",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1.8",
                  "versionStartIncluding": "6.6",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2",
                  "versionStartIncluding": "6.6",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nxsk: fix buffer leak in xsk_drop_skb() for AF_XDP multi-buffer Tx\n\nThis patch is inspired by the check[1] from sashiko. It says when\noverflow happens, the address of cq to be published is invalid.\nActually the severer thing is the whole process of publishing the\naddress of cq in this particular case is not right: it should truely\npublish the address and advance the cached_prod in cq as long as it\nreads descriptors from txq.\n\nThe following is the full analysis.\nxsk_drop_skb() is called in three places, which all discard a partially\nbuilt multi-buffer skb:\n1) xsk_build_skb() -EOVERFLOW error path: packet exceeds MAX_SKB_FRAGS\n2) __xsk_generic_xmit() post-loop cleanup: an invalid descriptor in\n   the TX ring prevents the partial packet from completing\n3) xsk_release(): socket close while xs-\u003eskb holds an incomplete packet\n\nIn all three cases, the TX descriptors for the already-processed frags\nhave been consumed from the TX ring (xskq_cons_release), and CQ slots\nhave been reserved. However, xsk_drop_skb() calls xsk_consume_skb()\nwhich cancels the CQ reservations via xsk_cq_cancel_locked(). Since\nthe buffer addresses never appear in the completion queue, userspace\npermanently loses track of these buffers.\n\nFix this by letting consume_skb() trigger the existing xsk_destruct_skb\ndestructor, which already submits buffer addresses to the CQ via\nxsk_cq_submit_addr_locked().\n\nNote that cancelling the descriptors back to the TX ring (via\nxskq_cons_cancel_n) is not a appropriate option because an oversized\npacket that always exceeds MAX_SKB_FRAGS would be retried indefinitely,\nwhich is an obviously deadlock bug in the TX path.\n\nAlso move the desc-\u003eaddr assignment in xsk_build_skb() above the\noverflow check so that the current descriptor\u0027s address is recorded\nbefore a potential -EOVERFLOW jump to free_err, consistent with the\nzerocopy path in xsk_build_skb_zerocopy().\n\n[1]: https://lore.kernel.org/all/20260425041726.85FB3C2BCB2@smtp.kernel.org/"
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-17T05:21:47.344Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/05e283466b86e0b25a5209a3eafe87aa9886064a"
        },
        {
          "url": "https://git.kernel.org/stable/c/a0528ab6af62bf57153caaf8ea28e5fcb0e18fd4"
        },
        {
          "url": "https://git.kernel.org/stable/c/a3c8382ebce4780c6b3ace2c09bc342313ac0186"
        }
      ],
      "title": "xsk: fix buffer leak in xsk_drop_skb() for AF_XDP multi-buffer Tx",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-74560",
    "datePublished": "2026-08-15T12:28:03.912Z",
    "dateReserved": "2026-08-15T05:44:03.916Z",
    "dateUpdated": "2026-08-17T05:21:47.344Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-74560",
      "date": "2026-08-18",
      "epss": "0.00155",
      "percentile": "0.0514"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-74560\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-08-15T13:18:01.483\",\"lastModified\":\"2026-08-17T06:19:54.100\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nxsk: fix buffer leak in xsk_drop_skb() for AF_XDP multi-buffer Tx\\n\\nThis patch is inspired by the check[1] from sashiko. It says when\\noverflow happens, the address of cq to be published is invalid.\\nActually the severer thing is the whole process of publishing the\\naddress of cq in this particular case is not right: it should truely\\npublish the address and advance the cached_prod in cq as long as it\\nreads descriptors from txq.\\n\\nThe following is the full analysis.\\nxsk_drop_skb() is called in three places, which all discard a partially\\nbuilt multi-buffer skb:\\n1) xsk_build_skb() -EOVERFLOW error path: packet exceeds MAX_SKB_FRAGS\\n2) __xsk_generic_xmit() post-loop cleanup: an invalid descriptor in\\n   the TX ring prevents the partial packet from completing\\n3) xsk_release(): socket close while xs-\u003eskb holds an incomplete packet\\n\\nIn all three cases, the TX descriptors for the already-processed frags\\nhave been consumed from the TX ring (xskq_cons_release), and CQ slots\\nhave been reserved. However, xsk_drop_skb() calls xsk_consume_skb()\\nwhich cancels the CQ reservations via xsk_cq_cancel_locked(). Since\\nthe buffer addresses never appear in the completion queue, userspace\\npermanently loses track of these buffers.\\n\\nFix this by letting consume_skb() trigger the existing xsk_destruct_skb\\ndestructor, which already submits buffer addresses to the CQ via\\nxsk_cq_submit_addr_locked().\\n\\nNote that cancelling the descriptors back to the TX ring (via\\nxskq_cons_cancel_n) is not a appropriate option because an oversized\\npacket that always exceeds MAX_SKB_FRAGS would be retried indefinitely,\\nwhich is an obviously deadlock bug in the TX path.\\n\\nAlso move the desc-\u003eaddr assignment in xsk_build_skb() above the\\noverflow check so that the current descriptor\u0027s address is recorded\\nbefore a potential -EOVERFLOW jump to free_err, consistent with the\\nzerocopy path in xsk_build_skb_zerocopy().\\n\\n[1]: https://lore.kernel.org/all/20260425041726.85FB3C2BCB2@smtp.kernel.org/\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"net/xdp/xsk.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"cf24f5a5feeaae34c1a34d1e04f8ac697290427a\",\"lessThan\":\"05e283466b86e0b25a5209a3eafe87aa9886064a\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"cf24f5a5feeaae34c1a34d1e04f8ac697290427a\",\"lessThan\":\"a0528ab6af62bf57153caaf8ea28e5fcb0e18fd4\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"cf24f5a5feeaae34c1a34d1e04f8ac697290427a\",\"lessThan\":\"a3c8382ebce4780c6b3ace2c09bc342313ac0186\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"net/xdp/xsk.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"6.6\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"6.6\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.18.44\",\"lessThanOrEqual\":\"6.18.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.1.8\",\"lessThanOrEqual\":\"7.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.2\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/05e283466b86e0b25a5209a3eafe87aa9886064a\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/a0528ab6af62bf57153caaf8ea28e5fcb0e18fd4\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/a3c8382ebce4780c6b3ace2c09bc342313ac0186\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}",
    "suse_vex": {
      "aggregate_severity": "not set",
      "current_release_date": "2026-08-15T23:50:13Z",
      "cve": "CVE-2026-74560",
      "id": "CVE-2026-74560",
      "initial_release_date": "2026-08-15T23:50:13Z",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-74560",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-74560.json",
      "version": "2"
    }
  }
}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

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.