FKIE_CVE-2026-23134

Vulnerability from fkie_nvd - Published: 2026-02-14 16:15 - Updated: 2026-02-18 17:52
Severity ?
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.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/99a3e3a1cfc93b8fe318c0a3a5cfb01f1d4ad53c
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/f60ba4a97ae3f94e4818722ed2e4d260bbb17b44
Impacted products
Vendor Product Version
To clipboard 

{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nslab: fix kmalloc_nolock() context check for PREEMPT_RT\n\nOn PREEMPT_RT kernels, local_lock becomes a sleeping lock. The current\ncheck in kmalloc_nolock() only verifies we\u0027re not in NMI or hard IRQ\ncontext, but misses the case where preemption is disabled.\n\nWhen a BPF program runs from a tracepoint with preemption disabled\n(preempt_count \u003e 0), kmalloc_nolock() proceeds to call\nlocal_lock_irqsave() which attempts to acquire a sleeping lock,\ntriggering:\n\n  BUG: sleeping function called from invalid context\n  in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 6128\n  preempt_count: 2, expected: 0\n\nFix this by checking !preemptible() on PREEMPT_RT, which directly\nexpresses the constraint that we cannot take a sleeping lock when\npreemption is disabled. This encompasses the previous checks for NMI\nand hard IRQ contexts while also catching cases where preemption is\ndisabled."
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nslab: correcci\u00f3n de la verificaci\u00f3n de contexto de kmalloc_nolock() para PREEMPT_RT\n\nEn kernels PREEMPT_RT, local_lock se convierte en un bloqueo de suspensi\u00f3n. La verificaci\u00f3n actual en kmalloc_nolock() solo verifica que no estamos en un contexto NMI o de IRQ dura, pero omite el caso en que la preemption est\u00e1 deshabilitada.\n\nCuando un programa BPF se ejecuta desde un tracepoint con la preemption deshabilitada (preempt_count \u0026gt; 0), kmalloc_nolock() procede a llamar a local_lock_irqsave(), que intenta adquirir un bloqueo de suspensi\u00f3n, lo que desencadena:\n\n  BUG: funci\u00f3n de suspensi\u00f3n llamada desde contexto inv\u00e1lido\n  in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 6128\n  preempt_count: 2, esperado: 0\n\nSolucione esto verificando !preemptible() en PREEMPT_RT, lo que expresa directamente la restricci\u00f3n de que no podemos tomar un bloqueo de suspensi\u00f3n cuando la preemption est\u00e1 deshabilitada. Esto abarca las verificaciones anteriores para contextos NMI e IRQ dura, al mismo tiempo que detecta casos en los que la preemption est\u00e1 deshabilitada."
    }
  ],
  "id": "CVE-2026-23134",
  "lastModified": "2026-02-18T17:52:44.520",
  "metrics": {},
  "published": "2026-02-14T16:15:53.377",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/99a3e3a1cfc93b8fe318c0a3a5cfb01f1d4ad53c"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/f60ba4a97ae3f94e4818722ed2e4d260bbb17b44"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Awaiting Analysis"
}


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 observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



Detection rules are retrieved from Rulezet.