CVE-2025-39736
Full vulnerability record from the local CVENow database.
Description
In the Linux kernel, the following vulnerability has been resolved: mm/kmemleak: avoid deadlock by moving pr_warn() outside kmemleak_lock When netpoll is enabled, calling pr_warn_once() while holding kmemleak_lock in mem_pool_alloc() can cause a deadlock due to lock inversion with the netconsole subsystem. This occurs because pr_warn_once() may trigger netpoll, which eventually leads to __alloc_skb() and back into kmemleak code, attempting to reacquire kmemleak_lock. This is the path for the deadlock. mem_pool_alloc() -> raw_spin_lock_irqsave(&kmemleak_lock, flags); -> pr_warn_once() -> netconsole subsystem -> netpoll -> __alloc_skb -> __create_object -> raw_spin_lock_irqsave(&kmemleak_lock, flags); Fix this by setting a flag and issuing the pr_warn_once() after kmemleak_lock is released.
Severity
MEDIUM
CVSS score
5.5
(v3.1)
Vulnerability status
Modified
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2025-09-11 17:15:34.840000
Last modified
2026-10-19 21:10:00.160000
View original CVE JSON
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"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2025-09-11T17:15:34.840",
"lastModified": "2026-10-19T21:10:00.160",
"vulnStatus": "Modified",
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"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/kmemleak: avoid deadlock by moving pr_warn() outside kmemleak_lock\n\nWhen netpoll is enabled, calling pr_warn_once() while holding\nkmemleak_lock in mem_pool_alloc() can cause a deadlock due to lock\ninversion with the netconsole subsystem. This occurs because\npr_warn_once() may trigger netpoll, which eventually leads to\n__alloc_skb() and back into kmemleak code, attempting to reacquire\nkmemleak_lock.\n\nThis is the path for the deadlock.\n\nmem_pool_alloc()\n -> raw_spin_lock_irqsave(&kmemleak_lock, flags);\n -> pr_warn_once()\n -> netconsole subsystem\n\t -> netpoll\n\t -> __alloc_skb\n\t\t -> __create_object\n\t\t -> raw_spin_lock_irqsave(&kmemleak_lock, flags);\n\nFix this by setting a flag and issuing the pr_warn_once() after\nkmemleak_lock is released."
},
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"lang": "es",
"value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nmm/kmemleak: evitar interbloqueo moviendo pr_warn() fuera de kmemleak_lock\n\nCuando netpoll está habilitado, llamar a pr_warn_once() mientras se mantiene kmemleak_lock en mem_pool_alloc() puede causar un interbloqueo debido a la inversión de bloqueo con el subsistema netconsole. Esto ocurre porque pr_warn_once() puede activar netpoll, lo que eventualmente lleva a __alloc_skb() y de vuelta al código de kmemleak, intentando readquirir kmemleak_lock.\n\nEste es el camino para el interbloqueo.\n\nmem_pool_alloc()\n -> raw_spin_lock_irqsave(&kmemleak_lock, flags);\n -> pr_warn_once()\n -> subsistema netconsole\n\t -> netpoll\n\t -> __alloc_skb\n\t\t -> __create_object\n\t\t -> raw_spin_lock_irqsave(&kmemleak_lock, flags);\n\nSolucione esto estableciendo una bandera y emitiendo el pr_warn_once() después de que kmemleak_lock sea liberado."
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