CVE-2026-74545 (GCVE-0-2026-74545)
Vulnerability from cvelistv5
Published
2026-08-15 12:27
Modified
2026-08-17 05:48
Severity ?
9.8 (Critical) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: rtase: fix double free of multi-frag skb on DMA map failure In rtase_start_xmit(), when the head buffer DMA mapping fails after rtase_xmit_frags() has mapped all fragments, the error path clears the fragment descriptors with rtase_tx_clear_range(), which frees the skb through the last-frag slot and accounts tx_dropped. Control then falls through to the common error label, which frees the same skb a second time and counts it again. Return right after clearing the fragments when the skb owns frags; the no-frag case still drops through and frees the head skb once.
References
Impacted products
Vendor Product Version
Linux Linux Version: d6e882b89fdf80be0ab4f914ec10f75215e49495
Version: d6e882b89fdf80be0ab4f914ec10f75215e49495
Version: d6e882b89fdf80be0ab4f914ec10f75215e49495
Version: d6e882b89fdf80be0ab4f914ec10f75215e49495
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/net/ethernet/realtek/rtase/rtase_main.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
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              "version": "d6e882b89fdf80be0ab4f914ec10f75215e49495",
              "versionType": "git"
            },
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              "status": "affected",
              "version": "d6e882b89fdf80be0ab4f914ec10f75215e49495",
              "versionType": "git"
            },
            {
              "lessThan": "de691dc3227b061c4d0beba9f0128fe1ff33dd68",
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              "version": "d6e882b89fdf80be0ab4f914ec10f75215e49495",
              "versionType": "git"
            },
            {
              "lessThan": "6fb7b769d6ed6d1d2e02af4a80e57a2477f35086",
              "status": "affected",
              "version": "d6e882b89fdf80be0ab4f914ec10f75215e49495",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/net/ethernet/realtek/rtase/rtase_main.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.12"
            },
            {
              "lessThan": "6.12",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.103",
              "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": "6.12.103",
                  "versionStartIncluding": "6.12",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.44",
                  "versionStartIncluding": "6.12",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1.8",
                  "versionStartIncluding": "6.12",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2",
                  "versionStartIncluding": "6.12",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nrtase: fix double free of multi-frag skb on DMA map failure\n\nIn rtase_start_xmit(), when the head buffer DMA mapping fails after\nrtase_xmit_frags() has mapped all fragments, the error path clears\nthe fragment descriptors with rtase_tx_clear_range(), which frees\nthe skb through the last-frag slot and accounts tx_dropped. Control\nthen falls through to the common error label, which frees the same\nskb a second time and counts it again.\n\nReturn right after clearing the fragments when the skb owns frags;\nthe no-frag case still drops through and frees the head skb once."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 9.8,
            "baseSeverity": "CRITICAL",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:N - The flaw is in rtase_start_xmit (ndo_start_xmit) on the Realtek Automotive Switch PCIe netdev; a remote peer can reach it by sending traffic that the host forwards, bridges, or answers out the rtase interface on automotive gateways and industrial routers without local shell access.\nAC:L - NETIF_F_SG enables multi-fragment TX skbs that rtase_xmit_frags maps before the head; an attacker can reliably create such packets and pressure SWIOTLB/IOVA resources with concurrent egress so the final head dma_map_single fails after fragment mapping succeeds, deterministically hitting the buggy error path.\nPR:N - Exploitation needs only the ability to inject or induce network traffic transmitted via the rtase netdev; no target credentials, capabilities, or local account are required on forwarding automotive/industrial gateways where this driver is deployed.\nUI:N - No victim interaction is required; the double free occurs automatically when the kernel queues a multi-fragment skb and the head DMA mapping fails during normal transmit error handling.\nS:U - The double free corrupts kernel heap allocator state on the host running the rtase driver; it does not cross VM, container, or IOMMU security boundaries.\nC:H - Double-freeing the same skb is kernel heap memory corruption that can corrupt freelist metadata and enable reuse of freed skb memory for arbitrary kernel memory disclosure, not merely a bounded leak.\nI:H - Heap corruption from freeing the same skb twice can be shaped into arbitrary kernel memory writes or control-flow hijacking via slab reuse, not limited to dropping a single packet.\nA:H - Double-freeing an skb reliably corrupts the slab allocator and can trigger immediate oops, panic, or watchdog reset; the attacker can repeat multi-fragment transmits under DMA pressure for sustained denial of service on safety-critical automotive networks."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-17T05:48:32.121Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/4f09172aff5f73a5e914f4fbc0d00a1c2ea9f7cb"
        },
        {
          "url": "https://git.kernel.org/stable/c/db986098f30881fafcc752800aa3b13fd289c922"
        },
        {
          "url": "https://git.kernel.org/stable/c/de691dc3227b061c4d0beba9f0128fe1ff33dd68"
        },
        {
          "url": "https://git.kernel.org/stable/c/6fb7b769d6ed6d1d2e02af4a80e57a2477f35086"
        }
      ],
      "title": "rtase: fix double free of multi-frag skb on DMA map failure",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-74545",
    "datePublished": "2026-08-15T12:27:54.536Z",
    "dateReserved": "2026-08-15T05:44:03.914Z",
    "dateUpdated": "2026-08-17T05:48:32.121Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


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