fkie_cve-2024-36943
Vulnerability from fkie_nvd
Published
2024-05-30 16:15
Modified
2024-11-21 09:22
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved: fs/proc/task_mmu: fix loss of young/dirty bits during pagemap scan make_uffd_wp_pte() was previously doing: pte = ptep_get(ptep); ptep_modify_prot_start(ptep); pte = pte_mkuffd_wp(pte); ptep_modify_prot_commit(ptep, pte); But if another thread accessed or dirtied the pte between the first 2 calls, this could lead to loss of that information. Since ptep_modify_prot_start() gets and clears atomically, the following is the correct pattern and prevents any possible race. Any access after the first call would see an invalid pte and cause a fault: pte = ptep_modify_prot_start(ptep); pte = pte_mkuffd_wp(pte); ptep_modify_prot_commit(ptep, pte);
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/74b3d66f91d9f539f99faad74d796fa9a389a015
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/c70dce4982ce1718bf978a35f8e26160b82081f4
af854a3a-2127-422b-91ae-364da2661108https://git.kernel.org/stable/c/74b3d66f91d9f539f99faad74d796fa9a389a015
af854a3a-2127-422b-91ae-364da2661108https://git.kernel.org/stable/c/c70dce4982ce1718bf978a35f8e26160b82081f4
Impacted products
Vendor Product Version


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{
   cveTags: [],
   descriptions: [
      {
         lang: "en",
         value: "In the Linux kernel, the following vulnerability has been resolved:\n\nfs/proc/task_mmu: fix loss of young/dirty bits during pagemap scan\n\nmake_uffd_wp_pte() was previously doing:\n\n  pte = ptep_get(ptep);\n  ptep_modify_prot_start(ptep);\n  pte = pte_mkuffd_wp(pte);\n  ptep_modify_prot_commit(ptep, pte);\n\nBut if another thread accessed or dirtied the pte between the first 2\ncalls, this could lead to loss of that information.  Since\nptep_modify_prot_start() gets and clears atomically, the following is the\ncorrect pattern and prevents any possible race.  Any access after the\nfirst call would see an invalid pte and cause a fault:\n\n  pte = ptep_modify_prot_start(ptep);\n  pte = pte_mkuffd_wp(pte);\n  ptep_modify_prot_commit(ptep, pte);",
      },
      {
         lang: "es",
         value: "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: fs/proc/task_mmu: corrige la pérdida de bits jóvenes/sucios durante el escaneo del mapa de páginas que make_uffd_wp_pte() estaba haciendo anteriormente: pte = ptep_get(ptep); ptep_modify_prot_start(ptep); pte = pte_mkuffd_wp(pte); ptep_modify_prot_commit(ptep,pte); Pero si otro hilo accedió o ensució el pte entre las 2 primeras llamadas, esto podría provocar la pérdida de esa información. Dado que ptep_modify_prot_start() obtiene y borra atómicamente, el siguiente es el patrón correcto y evita cualquier posible ejecución. Cualquier acceso después de la primera llamada vería un pte no válido y provocaría una falla: pte = ptep_modify_prot_start(ptep); pte = pte_mkuffd_wp(pte); ptep_modify_prot_commit(ptep,pte);",
      },
   ],
   id: "CVE-2024-36943",
   lastModified: "2024-11-21T09:22:52.417",
   metrics: {},
   published: "2024-05-30T16:15:17.307",
   references: [
      {
         source: "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
         url: "https://git.kernel.org/stable/c/74b3d66f91d9f539f99faad74d796fa9a389a015",
      },
      {
         source: "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
         url: "https://git.kernel.org/stable/c/c70dce4982ce1718bf978a35f8e26160b82081f4",
      },
      {
         source: "af854a3a-2127-422b-91ae-364da2661108",
         url: "https://git.kernel.org/stable/c/74b3d66f91d9f539f99faad74d796fa9a389a015",
      },
      {
         source: "af854a3a-2127-422b-91ae-364da2661108",
         url: "https://git.kernel.org/stable/c/c70dce4982ce1718bf978a35f8e26160b82081f4",
      },
   ],
   sourceIdentifier: "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
   vulnStatus: "Awaiting Analysis",
}


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