{"api_version":"1","generated_at":"2026-07-23T12:09:29+00:00","cve":"CVE-2025-39736","urls":{"html":"https://cve.report/CVE-2025-39736","api":"https://cve.report/api/cve/CVE-2025-39736.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2025-39736","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2025-39736"},"summary":{"title":"mm/kmemleak: avoid deadlock by moving pr_warn() outside kmemleak_lock","description":"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.","state":"PUBLISHED","assigner":"Linux","published_at":"2025-09-11 17:15:34","updated_at":"2026-05-12 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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 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avoid deadlock by moving pr_warn() outside kmemleak","CVE":"CVE-2025-39736","Year":"2025"},"notes":[{"CveYear":"2025","CveId":"39736","Ordinal":"1","NoteData":"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.","Type":"Description","Title":"mm/kmemleak: avoid deadlock by moving pr_warn() outside kmemleak"}]}}}