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CVE-2026-98567

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: net: xps: reject an out of range traffic class Only the entries below dev->num_tc are valid in dev->tc_to_txq[], and dev->prio_tc_map[] may only name classes below it. netdev_set_num_tc() lowers dev->num_tc without touching either array. netdev_txq_to_tc() walks all TC_MAX_QUEUE slots and netdev_get_prio_tc_map() returns the entry as it stands, so a leftover entry is handed out as a traffic class >= dev->num_tc. Taking that class from netdev_txq_to_tc(), __netif_set_xps_queue() rejects only a negative one and indexes an XPS map sized for dev->num_tc classes: tci = j * num_tc + tc; RCU_INIT_POINTER(new_dev_maps->attr_map[tci], map); attr_map[] holds nr_ids * num_tc entries and j runs over the ids named in the mask, so a class that is not below num_tc pushes tci past the end of the map for the last ids and the store overruns it. Any caller that lowers num_tc leaves such entries behind, and mqprio_destroy() tears down with netdev_set_num_tc(dev, 0) rather than netdev_reset_tc(). After mqprio with 8 classes then 1, tc_to_txq[1..7] still describe txq 1..7. The splat is from an XPS write to txq 2 on a veth with 8 rx queues: attr_map[] has 8 * 1 entries, tci = j + 2, and j == 6 stores one past the end of the 88-byte map: BUG: KASAN: slab-out-of-bounds in __netif_set_xps_queue (net/core/dev.c:2954) Write of size 8 at addr ffff88813016bc58 by task xps_oob/634 __netif_set_xps_queue (net/core/dev.c:2954) xps_rxqs_store (net/core/net-sysfs.c:1880) netdev_queue_attr_store (net/core/net-sysfs.c:1390) Allocated by task 634: __kmalloc_noprof (mm/slub.c:5439) __netif_set_xps_queue (net/core/dev.c:2937) The buggy address is located 0 bytes to the right of allocated 88-byte region [ffff88813016bc00, ffff88813016bc58) Reject a class the map has no room for.

Severity
Not scored
CVSS score
Not available
Vulnerability status
Received
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-10-18 16:17:08.870000
Last modified
2026-10-19 10:19:14.597000
View original CVE JSON
{
  "id": "CVE-2026-98567",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-10-18T16:17:08.870",
  "lastModified": "2026-10-19T10:19:14.597",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: xps: reject an out of range traffic class\n\nOnly the entries below dev->num_tc are valid in dev->tc_to_txq[], and\ndev->prio_tc_map[] may only name classes below it. netdev_set_num_tc()\nlowers dev->num_tc without touching either array.\n\nnetdev_txq_to_tc() walks all TC_MAX_QUEUE slots and\nnetdev_get_prio_tc_map() returns the entry as it stands, so a leftover\nentry is handed out as a traffic class >= dev->num_tc. Taking that\nclass from netdev_txq_to_tc(), __netif_set_xps_queue() rejects only a\nnegative one and indexes an XPS map sized for dev->num_tc classes:\n\n\ttci = j * num_tc + tc;\n\tRCU_INIT_POINTER(new_dev_maps->attr_map[tci], map);\n\nattr_map[] holds nr_ids * num_tc entries and j runs over the ids named\nin the mask, so a class that is not below num_tc pushes tci past the end\nof the map for the last ids and the store overruns it.\n\nAny caller that lowers num_tc leaves such entries behind, and\nmqprio_destroy() tears down with netdev_set_num_tc(dev, 0) rather than\nnetdev_reset_tc(). After mqprio with 8 classes then 1, tc_to_txq[1..7]\nstill describe txq 1..7. The splat is from an XPS write to txq 2 on a\nveth with 8 rx queues: attr_map[] has 8 * 1 entries, tci = j + 2, and\nj == 6 stores one past the end of the 88-byte map:\n\n  BUG: KASAN: slab-out-of-bounds in __netif_set_xps_queue (net/core/dev.c:2954)\n  Write of size 8 at addr ffff88813016bc58 by task xps_oob/634\n   __netif_set_xps_queue (net/core/dev.c:2954)\n   xps_rxqs_store (net/core/net-sysfs.c:1880)\n   netdev_queue_attr_store (net/core/net-sysfs.c:1390)\n  Allocated by task 634:\n   __kmalloc_noprof (mm/slub.c:5439)\n   __netif_set_xps_queue (net/core/dev.c:2937)\n  The buggy address is located 0 bytes to the right of\n   allocated 88-byte region [ffff88813016bc00, ffff88813016bc58)\n\nReject a class the map has no room for."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "net/core/dev.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "184c449f91fef521042970cca46bd5cdfc0e3a37",
              "lessThan": "967e10f40a0c6732db299cbe001df0e859196055",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "184c449f91fef521042970cca46bd5cdfc0e3a37",
              "lessThan": "1cb8e40525a72c9f1e1cf94c68c172b3b9bbdc81",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "184c449f91fef521042970cca46bd5cdfc0e3a37",
              "lessThan": "6ea8f643053f33622f9116e4e1db58306ece45e3",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "184c449f91fef521042970cca46bd5cdfc0e3a37",
              "lessThan": "9e841723ba482d41ecbf90241c756a16cdfea949",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "184c449f91fef521042970cca46bd5cdfc0e3a37",
              "lessThan": "eff227a3cb4d0089fbb85c73480bf8abf2e5ae7f",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "184c449f91fef521042970cca46bd5cdfc0e3a37",
              "lessThan": "2cc1c3977acbffc417fb5b57699d1df3dcffb5fd",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "184c449f91fef521042970cca46bd5cdfc0e3a37",
              "lessThan": "930318290d8509e864c015fe6c9239470b3c579c",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "184c449f91fef521042970cca46bd5cdfc0e3a37",
              "lessThan": "4da3b7b8b50f3e2fde54a4c18a82a8e3f6223910",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "net/core/dev.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "4.10",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "4.10",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "5.10.271",
              "lessThanOrEqual": "5.10.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "5.15.222",
              "lessThanOrEqual": "5.15.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.1.189",
              "lessThanOrEqual": "6.1.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.6.158",
              "lessThanOrEqual": "6.6.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.12.112",
              "lessThanOrEqual": "6.12.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.55",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2.9",
              "lessThanOrEqual": "7.2.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.3",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {},
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/1cb8e40525a72c9f1e1cf94c68c172b3b9bbdc81",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/2cc1c3977acbffc417fb5b57699d1df3dcffb5fd",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/4da3b7b8b50f3e2fde54a4c18a82a8e3f6223910",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/6ea8f643053f33622f9116e4e1db58306ece45e3",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/930318290d8509e864c015fe6c9239470b3c579c",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/967e10f40a0c6732db299cbe001df0e859196055",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/9e841723ba482d41ecbf90241c756a16cdfea949",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/eff227a3cb4d0089fbb85c73480bf8abf2e5ae7f",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}