CVE-2026-64121 (GCVE-0-2026-64121)
Vulnerability from cvelistv5
Published
2026-07-19 15:40
Modified
2026-07-19 15:40
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved: net: ifb: report ethtool stats over num_tx_queues ifb_dev_init() allocates dp->tx_private to dev->num_tx_queues entries via kzalloc_objs(*txp, dev->num_tx_queues). Both IFB per-queue RX and TX stats live in those entries: ifb_xmit() updates txp->rx_stats using the skb queue mapping, ifb_ri_tasklet() updates txp->tx_stats, and ifb_stats64() aggregates both over dev->num_tx_queues. The ethtool stats callbacks instead size and walk the per-queue stats with dev->real_num_rx_queues and dev->real_num_tx_queues. With an asymmetric device where the RX queue count exceeds the TX queue count, for example: ip link add name ifb10 numtxqueues 1 numrxqueues 8 type ifb ethtool -S ifb10 ifb_get_ethtool_stats() indexes past the tx_private allocation and copies adjacent slab data through ETHTOOL_GSTATS. Use dev->num_tx_queues consistently for the stats strings, the stats count, and the stats data walks. This reports one RX stats group and one TX stats group for each backing ifb_q_private entry, which is the queue set IFB can actually populate. Reproduced under UML+KASAN at v7.1-rc2: BUG: KASAN: slab-out-of-bounds in ifb_fill_stats_data+0x3c/0xae Read of size 8 at addr 0000000062dbd228 by task ethtool/36 ifb_fill_stats_data+0x3c/0xae ifb_get_ethtool_stats+0xc0/0x129 __dev_ethtool+0x1ca5/0x363c dev_ethtool+0x123/0x1b3 dev_ioctl+0x56c/0x744 sock_do_ioctl+0x15f/0x1b2 sock_ioctl+0x4d5/0x50a sys_ioctl+0xd8b/0xde9 With the patch applied, the same UML+KASAN repro is silent and ethtool -S ifb10 reports only the stats backed by the single allocated tx_private entry.
References
Impacted products
Vendor Product Version
Linux Linux Version: a21ee5b2fcb8d6d3973446c5039e966c4cfe40d1
Version: a21ee5b2fcb8d6d3973446c5039e966c4cfe40d1
Version: a21ee5b2fcb8d6d3973446c5039e966c4cfe40d1
Version: a21ee5b2fcb8d6d3973446c5039e966c4cfe40d1
Version: a21ee5b2fcb8d6d3973446c5039e966c4cfe40d1
Version: a21ee5b2fcb8d6d3973446c5039e966c4cfe40d1
 Create a notification for this product.
Show details on NVD website

To clipboard 

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/net/ifb.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "6afdb8113cb007f9332f59a9b7fd45731b8a9de5",
              "status": "affected",
              "version": "a21ee5b2fcb8d6d3973446c5039e966c4cfe40d1",
              "versionType": "git"
            },
            {
              "lessThan": "16bd798cb6d8337d7c3eea1adc412f31b5181d5b",
              "status": "affected",
              "version": "a21ee5b2fcb8d6d3973446c5039e966c4cfe40d1",
              "versionType": "git"
            },
            {
              "lessThan": "301a554e458e2f5ec47f2c336a7cb03b877f9fd6",
              "status": "affected",
              "version": "a21ee5b2fcb8d6d3973446c5039e966c4cfe40d1",
              "versionType": "git"
            },
            {
              "lessThan": "f8a5a76b4a683043c6eff2a060bcaa17f9316ad5",
              "status": "affected",
              "version": "a21ee5b2fcb8d6d3973446c5039e966c4cfe40d1",
              "versionType": "git"
            },
            {
              "lessThan": "2638e1773904d7aa8f24c6e7fda2ed7d69df6fa4",
              "status": "affected",
              "version": "a21ee5b2fcb8d6d3973446c5039e966c4cfe40d1",
              "versionType": "git"
            },
            {
              "lessThan": "5db89c99566fc4728cc92e941d8e1975711e24b5",
              "status": "affected",
              "version": "a21ee5b2fcb8d6d3973446c5039e966c4cfe40d1",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/net/ifb.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.17"
            },
            {
              "lessThan": "5.17",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.175",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.142",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.92",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.34",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.0.*",
              "status": "unaffected",
              "version": "7.0.11",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1.175",
                  "versionStartIncluding": "5.17",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.142",
                  "versionStartIncluding": "5.17",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.92",
                  "versionStartIncluding": "5.17",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.34",
                  "versionStartIncluding": "5.17",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.0.11",
                  "versionStartIncluding": "5.17",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1",
                  "versionStartIncluding": "5.17",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: ifb: report ethtool stats over num_tx_queues\n\nifb_dev_init() allocates dp-\u003etx_private to dev-\u003enum_tx_queues\nentries via kzalloc_objs(*txp, dev-\u003enum_tx_queues). Both IFB\nper-queue RX and TX stats live in those entries: ifb_xmit() updates\ntxp-\u003erx_stats using the skb queue mapping, ifb_ri_tasklet() updates\ntxp-\u003etx_stats, and ifb_stats64() aggregates both over\ndev-\u003enum_tx_queues.\n\nThe ethtool stats callbacks instead size and walk the per-queue\nstats with dev-\u003ereal_num_rx_queues and dev-\u003ereal_num_tx_queues. With\nan asymmetric device where the RX queue count exceeds the TX queue\ncount, for example:\n\n    ip link add name ifb10 numtxqueues 1 numrxqueues 8 type ifb\n    ethtool -S ifb10\n\nifb_get_ethtool_stats() indexes past the tx_private allocation and\ncopies adjacent slab data through ETHTOOL_GSTATS.\n\nUse dev-\u003enum_tx_queues consistently for the stats strings, the\nstats count, and the stats data walks. This reports one RX stats\ngroup and one TX stats group for each backing ifb_q_private entry,\nwhich is the queue set IFB can actually populate.\n\nReproduced under UML+KASAN at v7.1-rc2:\n\n  BUG: KASAN: slab-out-of-bounds in ifb_fill_stats_data+0x3c/0xae\n  Read of size 8 at addr 0000000062dbd228 by task ethtool/36\n  ifb_fill_stats_data+0x3c/0xae\n  ifb_get_ethtool_stats+0xc0/0x129\n  __dev_ethtool+0x1ca5/0x363c\n  dev_ethtool+0x123/0x1b3\n  dev_ioctl+0x56c/0x744\n  sock_do_ioctl+0x15f/0x1b2\n  sock_ioctl+0x4d5/0x50a\n  sys_ioctl+0xd8b/0xde9\n\nWith the patch applied, the same UML+KASAN repro is silent and\nethtool -S ifb10 reports only the stats backed by the single\nallocated tx_private entry."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-07-19T15:40:19.745Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/6afdb8113cb007f9332f59a9b7fd45731b8a9de5"
        },
        {
          "url": "https://git.kernel.org/stable/c/16bd798cb6d8337d7c3eea1adc412f31b5181d5b"
        },
        {
          "url": "https://git.kernel.org/stable/c/301a554e458e2f5ec47f2c336a7cb03b877f9fd6"
        },
        {
          "url": "https://git.kernel.org/stable/c/f8a5a76b4a683043c6eff2a060bcaa17f9316ad5"
        },
        {
          "url": "https://git.kernel.org/stable/c/2638e1773904d7aa8f24c6e7fda2ed7d69df6fa4"
        },
        {
          "url": "https://git.kernel.org/stable/c/5db89c99566fc4728cc92e941d8e1975711e24b5"
        }
      ],
      "title": "net: ifb: report ethtool stats over num_tx_queues",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-64121",
    "datePublished": "2026-07-19T15:40:19.745Z",
    "dateReserved": "2026-07-19T07:54:57.036Z",
    "dateUpdated": "2026-07-19T15:40:19.745Z",
    "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 seen somewhere by the user.
  • Confirmed: The vulnerability is confirmed from an analyst perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
  • Patched: This vulnerability was successfully patched by the user reporting the sighting.
  • Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
  • Not confirmed: The user expresses doubt about the veracity of the vulnerability.
  • Not patched: This vulnerability was not successfully patched by the user reporting the sighting.