{"id":"CVE-2025-39736","state":"PUBLISHED","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.","publishedAt":"2025-09-11T16:52:11.772Z","updatedAt":"2026-05-12T12:06:38.396Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"c5665868183fec689dbab9fb8505188b2c4f0757","status":"affected","lessThan":"c7b6ea0ede687e7460e593c5ea478f50aa41682a","versionType":"git"},{"version":"c5665868183fec689dbab9fb8505188b2c4f0757","status":"affected","lessThan":"4b0151e1d468eb2667c37b7af99b3c075072d334","versionType":"git"},{"version":"c5665868183fec689dbab9fb8505188b2c4f0757","status":"affected","lessThan":"f249d32bb54876b4b6c3ae071af8ddca77af390b","versionType":"git"},{"version":"c5665868183fec689dbab9fb8505188b2c4f0757","status":"affected","lessThan":"62879faa8efe8d8a9c7bf7606ee9c068012d7dac","versionType":"git"},{"version":"c5665868183fec689dbab9fb8505188b2c4f0757","status":"affected","lessThan":"1da95d3d4b7b1d380ebd87b71a61e7e6aed3265d","versionType":"git"},{"version":"c5665868183fec689dbab9fb8505188b2c4f0757","status":"affected","lessThan":"a0854de00ce2ee27edf39037e7836ad580eb3350","versionType":"git"},{"version":"c5665868183fec689dbab9fb8505188b2c4f0757","status":"affected","lessThan":"08f70be5e406ce47c822f2dd11c1170ca259605b","versionType":"git"},{"version":"c5665868183fec689dbab9fb8505188b2c4f0757","status":"affected","lessThan":"a181b228b37a6a5625dad2bb4265bb7abb673e9f","versionType":"git"},{"version":"c5665868183fec689dbab9fb8505188b2c4f0757","status":"affected","lessThan":"47b0f6d8f0d2be4d311a49e13d2fd5f152f492b2","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["mm/kmemleak.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.4","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.4","versionType":"semver"},{"version":"5.4.297","status":"unaffected","lessThanOrEqual":"5.4.*","versionType":"semver"},{"version":"5.10.241","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.190","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.149","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.103","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.43","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.15.11","status":"unaffected","lessThanOrEqual":"6.15.*","versionType":"semver"},{"version":"6.16.2","status":"unaffected","lessThanOrEqual":"6.16.*","versionType":"semver"},{"version":"6.17","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["mm/kmemleak.c"]}],"references":["https://git.kernel.org/stable/c/c7b6ea0ede687e7460e593c5ea478f50aa41682a","https://git.kernel.org/stable/c/4b0151e1d468eb2667c37b7af99b3c075072d334","https://git.kernel.org/stable/c/f249d32bb54876b4b6c3ae071af8ddca77af390b","https://git.kernel.org/stable/c/62879faa8efe8d8a9c7bf7606ee9c068012d7dac","https://git.kernel.org/stable/c/1da95d3d4b7b1d380ebd87b71a61e7e6aed3265d","https://git.kernel.org/stable/c/a0854de00ce2ee27edf39037e7836ad580eb3350","https://git.kernel.org/stable/c/08f70be5e406ce47c822f2dd11c1170ca259605b","https://git.kernel.org/stable/c/a181b228b37a6a5625dad2bb4265bb7abb673e9f","https://git.kernel.org/stable/c/47b0f6d8f0d2be4d311a49e13d2fd5f152f492b2","https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html","https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html","https://cert-portal.siemens.com/productcert/html/ssa-032379.html"],"weaknesses":[],"ingestedAt":"2026-10-29T20:09:09.358Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2025/39xxx/CVE-2025-39736.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2025-39736","state":"PUBLISHED","datePublished":"2025-09-11T16:52:11.772Z","dateUpdated":"2026-05-12T12:06:38.396Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2025-04-16T07:20:57.119Z"},"containers":{"cna":{"title":"mm/kmemleak: avoid deadlock by moving pr_warn() outside kmemleak_lock","descriptions":[{"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 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