{"id":"CVE-2025-39736","title":"mm/kmemleak: avoid deadlock by moving pr_warn() outside kmemleak_lock","summary":"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() c…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= c5665868183fec689dbab9fb8505188b2c4f0757 < c7b6ea0ede687e7460e593c5ea478f50aa41682a","Linux >= c5665868183fec689dbab9fb8505188b2c4f0757 < 4b0151e1d468eb2667c37b7af99b3c075072d334","Linux >= c5665868183fec689dbab9fb8505188b2c4f0757 < f249d32bb54876b4b6c3ae071af8ddca77af390b","Linux >= c5665868183fec689dbab9fb8505188b2c4f0757 < 62879faa8efe8d8a9c7bf7606ee9c068012d7dac","Linux >= c5665868183fec689dbab9fb8505188b2c4f0757 < 1da95d3d4b7b1d380ebd87b71a61e7e6aed3265d","Linux >= c5665868183fec689dbab9fb8505188b2c4f0757 < a0854de00ce2ee27edf39037e7836ad580eb3350","Linux >= c5665868183fec689dbab9fb8505188b2c4f0757 < 08f70be5e406ce47c822f2dd11c1170ca259605b","Linux >= c5665868183fec689dbab9fb8505188b2c4f0757 < a181b228b37a6a5625dad2bb4265bb7abb673e9f","Linux >= c5665868183fec689dbab9fb8505188b2c4f0757 < 47b0f6d8f0d2be4d311a49e13d2fd5f152f492b2","Linux 5.4"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-11-05T21:08:53.202255Z"},"published":"2025-09-11","updated":"2026-11-05","sourceUpdated":"2026-11-05T21:12:55.882Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2025-39736","references":[{"url":"https://git.kernel.org/stable/c/c7b6ea0ede687e7460e593c5ea478f50aa41682a"},{"url":"https://git.kernel.org/stable/c/4b0151e1d468eb2667c37b7af99b3c075072d334"},{"url":"https://git.kernel.org/stable/c/f249d32bb54876b4b6c3ae071af8ddca77af390b"},{"url":"https://git.kernel.org/stable/c/62879faa8efe8d8a9c7bf7606ee9c068012d7dac"},{"url":"https://git.kernel.org/stable/c/1da95d3d4b7b1d380ebd87b71a61e7e6aed3265d"},{"url":"https://git.kernel.org/stable/c/a0854de00ce2ee27edf39037e7836ad580eb3350"},{"url":"https://git.kernel.org/stable/c/08f70be5e406ce47c822f2dd11c1170ca259605b"},{"url":"https://git.kernel.org/stable/c/a181b228b37a6a5625dad2bb4265bb7abb673e9f"},{"url":"https://git.kernel.org/stable/c/47b0f6d8f0d2be4d311a49e13d2fd5f152f492b2"}],"tags":["cve.org"],"epss":0.00133,"epssPercentile":0.02882,"ingestedAt":"2026-11-05T22:38:32.021Z","slug":"CVE-2025-39736","body":"## Overview\n\nIn 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.\n\n## Affected\n\n- `Linux >= c5665868183fec689dbab9fb8505188b2c4f0757 < c7b6ea0ede687e7460e593c5ea478f50aa41682a`\n- `Linux >= c5665868183fec689dbab9fb8505188b2c4f0757 < 4b0151e1d468eb2667c37b7af99b3c075072d334`\n- `Linux >= c5665868183fec689dbab9fb8505188b2c4f0757 < f249d32bb54876b4b6c3ae071af8ddca77af390b`\n- `Linux >= c5665868183fec689dbab9fb8505188b2c4f0757 < 62879faa8efe8d8a9c7bf7606ee9c068012d7dac`\n- `Linux >= c5665868183fec689dbab9fb8505188b2c4f0757 < 1da95d3d4b7b1d380ebd87b71a61e7e6aed3265d`\n- `Linux >= c5665868183fec689dbab9fb8505188b2c4f0757 < a0854de00ce2ee27edf39037e7836ad580eb3350`\n- `Linux >= c5665868183fec689dbab9fb8505188b2c4f0757 < 08f70be5e406ce47c822f2dd11c1170ca259605b`\n- `Linux >= c5665868183fec689dbab9fb8505188b2c4f0757 < a181b228b37a6a5625dad2bb4265bb7abb673e9f`\n- `Linux >= c5665868183fec689dbab9fb8505188b2c4f0757 < 47b0f6d8f0d2be4d311a49e13d2fd5f152f492b2`\n- `Linux 5.4`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}