CVE-2025-39737
Estado: ModificadaMedia (5.5)—
In the Linux kernel, the following vulnerability has been resolved:
mm/kmemleak: avoid soft lockup in __kmemleak_do_cleanup()
A soft lockup warning was observed on a relative small system x86-64 system with 16 GB of memory when running a debug kernel with kmemleak enabled.
The test system was running a workload with hot unplug happening in parallel. Then kemleak decided to disable itself due to its inability to allocate more kmemleak objects. The debug kernel has its CONFIG_DEBUG_KMEMLEAK_MEM_POOL_SIZE set to 40,000.
The soft lockup happened in kmemleak_do_cleanup() when the existing kmemleak objects were being removed and deleted one-by-one in a loop via a workqueue.
Leer descripción completaMostrar menos
In this particular case, there are at least 40,000 objects that need to be processed and given the slowness of a debug kernel and the fact that a raw_spinlock has to be acquired and released in __delete_object(), it could take a while to properly handle all these objects.
As kmemleak has been disabled in this case, the object removal and deletion process can be further optimized as locking isn't really needed. However, it is probably not worth the effort to optimize for such an edge case that should rarely happen. So the simple solution is to call cond_resched() at periodic interval in the iteration loop to avoid soft lockup.
Detalles técnicos trazas, registros y código del informe original
watchdog: BUG: soft lockup - CPU#8 stuck for 33s! [kworker/8:1:134]
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- Puntuación base: 5.5
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.18%
- Percentil entre todas las CVEs puntuadas: 6
- Fecha de la puntuación: 6/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
Tecnologías afectadas (2)
CWE
- CWE-401
Referencias
- https://git.kernel.org/stable/c/1ef72a7fedc5bca70e8cc980985790de10d407aa
- https://git.kernel.org/stable/c/8d2d22a55ffe35c38e69795468a7addd1a80e9ce
- https://git.kernel.org/stable/c/926092268efdf1ed7b55cf486356c74a9e7710d1
- https://git.kernel.org/stable/c/9b80430c194e4a114dc663c1025d56b4f3d0153d
- https://git.kernel.org/stable/c/9f1f4e95031f84867c5821540466d62f88dab8ca
- https://git.kernel.org/stable/c/a04de4c40aab9b338dfa989cf4aec70fd187eeb2
- https://git.kernel.org/stable/c/d1534ae23c2b6be350c8ab060803fbf6e9682adc
- https://git.kernel.org/stable/c/e21a3ddd58733ce31afcb1e5dc3cb80a4b5bc29b
- https://git.kernel.org/stable/c/f014c10d190b92aad366e56b445daffcd1c075e4
- https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html
- https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html
- https://cert-portal.siemens.com/productcert/html/ssa-032379.html
JSON original (NVD)
Mostrar
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"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/kmemleak: avoid soft lockup in __kmemleak_do_cleanup()\n\nA soft lockup warning was observed on a relative small system x86-64\nsystem with 16 GB of memory when running a debug kernel with kmemleak\nenabled.\n\n watchdog: BUG: soft lockup - CPU#8 stuck for 33s! [kworker/8:1:134]\n\nThe test system was running a workload with hot unplug happening in\nparallel. Then kemleak decided to disable itself due to its inability to\nallocate more kmemleak objects. The debug kernel has its\nCONFIG_DEBUG_KMEMLEAK_MEM_POOL_SIZE set to 40,000.\n\nThe soft lockup happened in kmemleak_do_cleanup() when the existing\nkmemleak objects were being removed and deleted one-by-one in a loop via a\nworkqueue. In this particular case, there are at least 40,000 objects\nthat need to be processed and given the slowness of a debug kernel and the\nfact that a raw_spinlock has to be acquired and released in\n__delete_object(), it could take a while to properly handle all these\nobjects.\n\nAs kmemleak has been disabled in this case, the object removal and\ndeletion process can be further optimized as locking isn't really needed. \nHowever, it is probably not worth the effort to optimize for such an edge\ncase that should rarely happen. So the simple solution is to call\ncond_resched() at periodic interval in the iteration loop to avoid soft\nlockup."
}
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