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net: cap tx_queue_len at S16_MAX to prevent oversized ring allocations

Type: advisorySource: Official CVE List1 source record

In the Linux kernel, the following vulnerability has been resolved: net: cap tx_queue_len at S16_MAX to prevent oversized ring allocations Several subsystems allocate ring buffers sized by dev->tx_queue_len with no upper bound. An unprivileged user (via unshare -Urn) can set a huge tx_queue_len and exhaust global memory with ring allocations: - pfifo_fast: pfifo_fast_init() and pfifo_fast_change_tx_queue_len() allocate 3 skb_array rings of tx_queue_len entries each. - tun: tun_queue_resize() and the queue-attach path resize ptr_rings to tx_queue_len on the NETDEV_CHANGE_TX_QUEUE_LEN notifier. - tap (macvtap/ipvtap): tap_queue_resize() and tap_init() resize/init ptr_rings to tx_queue_len on the same notifier. netif_change_tx_queue_len() is the single entry point for IFLA_TXQLEN, sysfs, and the SIOCSIFTXQLEN ioctl. Cap new_len at S16_MAX (32767) there so the oversized value is rejected at set time. This takes effect whether the device is up or down, before dev->tx_queue_len is written, before any notifier fires, and before any ring is allocated. The "> S16_MAX" check also subsumes the previous unsigned-long truncation test, and a negative ifr_qlen from the ioctl lands far above the cap after conversion, so both old failure modes are covered by the one comparison. tx_queue_len is ambigious: both a per-ring sizing multiplier and a default queue-length/limit knob for consumers that allocate nothing at set time (pfifo/bfifo/gred/plug/sfb limits, htb direct_qlen, qfq max_classes, te

Announced Source revision 1
Original source ↗

CVE-2026-98022

Primary source · Revision 1

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2026-98022

Linux

Source reference: /containers/cna/affected/0/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Linux

Source reference: /containers/cna/affected/1/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Structured affected-version data

Original package identities and version rules from this source.

[
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "6a643ddb5624be7e0694d49f5765a8d41c1ab6d0",
        "lessThan": "24d02c909a1725ab9eceb92db7d02e4e841f17ca",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "6a643ddb5624be7e0694d49f5765a8d41c1ab6d0",
        "lessThan": "5e5591a0f33f7c11bf1d338dbb6c5072575de64c",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "6a643ddb5624be7e0694d49f5765a8d41c1ab6d0",
        "lessThan": "c8d4060610c69645733c92d94fceb4b93808ac4d",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "6a643ddb5624be7e0694d49f5765a8d41c1ab6d0",
        "lessThan": "c2362c500931e5bd1826bce34e9ce28af80e7541",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "6a643ddb5624be7e0694d49f5765a8d41c1ab6d0",
        "lessThan": "81c0e02076989743a603806a5a4f44d2c40dc01f",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "6a643ddb5624be7e0694d49f5765a8d41c1ab6d0",
        "lessThan": "081340cf70a789b94b4174af54a63ffd49677a4e",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "6a643ddb5624be7e0694d49f5765a8d41c1ab6d0",
        "lessThan": "a03b927bae4af5c23fd5315a237855c17cc8f422",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "6a643ddb5624be7e0694d49f5765a8d41c1ab6d0",
        "lessThan": "66ab4c59b74db7ab53a1c9083feaaede393a96a0",
        "versionType": "git"
      }
    ],
    "programFiles": [
      "net/core/dev.c"
    ],
    "defaultStatus": "unaffected"
  },
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "4.16"
      },
      {
        "status": "unaffected",
        "version": "0",
        "lessThan": "4.16",
        "versionType": "semver"
      },
      {
        "status": "unaffected",
        "version": "5.10.271",
        "versionType": "semver",
        "lessThanOrEqual": "5.10.*"
      },
      {
        "status": "unaffected",
        "version": "5.15.222",
        "versionType": "semver",
        "lessThanOrEqual": "5.15.*"
      },
      {
        "status": "unaffected",
        "version": "6.1.189",
        "versionType": "semver",
        "lessThanOrEqual": "6.1.*"
      },
      {
        "status": "unaffected",
        "version": "6.6.158",
        "versionType": "semver",
        "lessThanOrEqual": "6.6.*"
      },
      {
        "status": "unaffected",
        "version": "6.12.111",
        "versionType": "semver",
        "lessThanOrEqual": "6.12.*"
      },
      {
        "status": "unaffected",
        "version": "6.18.53",
        "versionType": "semver",
        "lessThanOrEqual": "6.18.*"
      },
      {
        "status": "unaffected",
        "version": "7.2.7",
        "versionType": "semver",
        "lessThanOrEqual": "7.2.*"
      },
      {
        "status": "unaffected",
        "version": "7.3",
        "versionType": "original_commit_for_fix",
        "lessThanOrEqual": "*"
      }
    ],
    "programFiles": [
      "net/core/dev.c"
    ],
    "defaultStatus": "affected"
  }
]
Related CVEs
CVE-2026-98022

Source reference: /cveMetadata/cveId

Publisher severity

No explicit severity was provided.

Event
#38145 · Revision 1
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