slab: fix kmalloc_nolock() context check for PREEMPT_RT

{
  "id": "a0674e91ebb9fcfef2ac4fc9d702649422edeb16471ab0e83dc4f05d8eeb07c2",
  "url": "https://osv.dev/vulnerability/CVE-2026-23134",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "slab: fix kmalloc_nolock() context check for PREEMPT_RT",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: slab: fix kmalloc_nolock() context check for PREEMPT_RT On PREEMPT_RT kernels, local_lock becomes a sleeping lock. The current check in kmalloc_nolock() only verifies we're not in NMI or hard IRQ context, but misses the case where preemption is disabled. When a BPF program runs from a tracepoint with preemption disabled (preempt_count > 0), kmalloc_nolock() proceeds to call local_lock_irqsave() which attempts to acquire a sleeping lock, triggering: BUG: sleeping function called from invalid context in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 6128 preempt_count: 2, expected: 0 Fix this by checking !preemptible() on PREEMPT_RT, which directly expresses the constraint that we cannot take a sleeping lock when preemption is disabled. This encompasses the previous checks for NMI and hard IRQ contexts while also catching cases where preemption is disabled.",
    "evidence": "osv:CVE-2026-23134",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.18.8",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2026-23134",
      "aliases": [
        "CVE-2026-23134"
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "af92793e52c3a99b828ed4bdd277fd3e11c18d08"
                },
                {
                  "fixed": "f60ba4a97ae3f94e4818722ed2e4d260bbb17b44"
                },
                {
                  "fixed": "99a3e3a1cfc93b8fe318c0a3a5cfb01f1d4ad53c"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-23134.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.18.0"
                },
                {
                  "fixed": "6.18.8"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-23134.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:23.147578806Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/99a3e3a1cfc93b8fe318c0a3a5cfb01f1d4ad53c",
        "https://git.kernel.org/stable/c/f60ba4a97ae3f94e4818722ed2e4d260bbb17b44",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23134.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-23134",
        "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
      ],
      "provider_metadata": {
        "cna_assigner": "Linux",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23134.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-23134",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 489405,
  "published_at": "2026-02-14T15:14:33.806+00:00"
}