# CVE-2025-39736: mm/kmemleak: avoid deadlock by moving pr_warn() outside kmemleak_lock CVE-2025-39736 is fixed in 31 products on 1 platform, first by ALAS2023-2025-1186, released September 10, 2025. It is not reported as exploited. Patch Radar priority: Routine. - Web page: https://patchblox.com/security/cve/CVE-2025-39736 - Priority: Routine - CVSS: 5.5 (Moderate) - EPSS: 0.0013 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: Sep 10, 2025 - Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-39736 ## 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. ## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Linux | bpftool amzn 2023 | 1:6.1.150-174.273.amzn2023 | [ALAS2023-2025-1186](https://patchblox.com/security/data/fix/linux/alas2023-2025-1186.md) | Sep 10, 2025 | | Linux | bpftool-debuginfo amzn 2023 | 1:6.1.150-174.273.amzn2023 | [ALAS2023-2025-1186](https://patchblox.com/security/data/fix/linux/alas2023-2025-1186.md) | Sep 10, 2025 | | Linux | kernel amzn 2023 | 1:6.1.150-174.273.amzn2023 | [ALAS2023-2025-1186](https://patchblox.com/security/data/fix/linux/alas2023-2025-1186.md) | Sep 10, 2025 | | Linux | kernel-debuginfo amzn 2023 | 1:6.1.150-174.273.amzn2023 | [ALAS2023-2025-1186](https://patchblox.com/security/data/fix/linux/alas2023-2025-1186.md) | Sep 10, 2025 | | Linux | kernel-debuginfo-common-aarch64 amzn 2023 | 1:6.1.150-174.273.amzn2023 | [ALAS2023-2025-1186](https://patchblox.com/security/data/fix/linux/alas2023-2025-1186.md) | Sep 10, 2025 | | Linux | kernel-debuginfo-common-x86_64 amzn 2023 | 1:6.1.150-174.273.amzn2023 | [ALAS2023-2025-1186](https://patchblox.com/security/data/fix/linux/alas2023-2025-1186.md) | Sep 10, 2025 | | Linux | kernel-devel amzn 2023 | 1:6.1.150-174.273.amzn2023 | [ALAS2023-2025-1186](https://patchblox.com/security/data/fix/linux/alas2023-2025-1186.md) | Sep 10, 2025 | | Linux | kernel-headers amzn 2023 | 1:6.1.150-174.273.amzn2023 | [ALAS2023-2025-1186](https://patchblox.com/security/data/fix/linux/alas2023-2025-1186.md) | Sep 10, 2025 | | Linux | kernel-libbpf amzn 2023 | 1:6.1.150-174.273.amzn2023 | [ALAS2023-2025-1186](https://patchblox.com/security/data/fix/linux/alas2023-2025-1186.md) | Sep 10, 2025 | | Linux | kernel-libbpf-debuginfo amzn 2023 | 1:6.1.150-174.273.amzn2023 | [ALAS2023-2025-1186](https://patchblox.com/security/data/fix/linux/alas2023-2025-1186.md) | Sep 10, 2025 | | Linux | kernel-libbpf-devel amzn 2023 | 1:6.1.150-174.273.amzn2023 | [ALAS2023-2025-1186](https://patchblox.com/security/data/fix/linux/alas2023-2025-1186.md) | Sep 10, 2025 | | Linux | kernel-libbpf-static amzn 2023 | 1:6.1.150-174.273.amzn2023 | [ALAS2023-2025-1186](https://patchblox.com/security/data/fix/linux/alas2023-2025-1186.md) | Sep 10, 2025 | | Linux | kernel-livepatch-6.1.150-174.273 amzn 2023 | 1:1.0-0.amzn2023 | [ALAS2023-2025-1186](https://patchblox.com/security/data/fix/linux/alas2023-2025-1186.md) | Sep 10, 2025 | | Linux | kernel-modules-extra amzn 2023 | 1:6.1.150-174.273.amzn2023 | [ALAS2023-2025-1186](https://patchblox.com/security/data/fix/linux/alas2023-2025-1186.md) | Sep 10, 2025 | | Linux | kernel-modules-extra-common amzn 2023 | 1:6.1.150-174.273.amzn2023 | [ALAS2023-2025-1186](https://patchblox.com/security/data/fix/linux/alas2023-2025-1186.md) | Sep 10, 2025 | | Linux | kernel-tools amzn 2023 | 1:6.1.150-174.273.amzn2023 | [ALAS2023-2025-1186](https://patchblox.com/security/data/fix/linux/alas2023-2025-1186.md) | Sep 10, 2025 | | Linux | kernel-tools-debuginfo amzn 2023 | 1:6.1.150-174.273.amzn2023 | [ALAS2023-2025-1186](https://patchblox.com/security/data/fix/linux/alas2023-2025-1186.md) | Sep 10, 2025 | | Linux | kernel-tools-devel amzn 2023 | 1:6.1.150-174.273.amzn2023 | [ALAS2023-2025-1186](https://patchblox.com/security/data/fix/linux/alas2023-2025-1186.md) | Sep 10, 2025 | | Linux | kernel-uek ol 8 | 0:5.4.17-2136.348.3.el7uek | [ELSA-2025-20663](https://patchblox.com/security/data/fix/linux/elsa-2025-20663.md) | Oct 11, 2025 | | Linux | kernel-uek-container ol 8 | 0:5.4.17-2136.348.3.el7uek | [ELSA-2025-20663](https://patchblox.com/security/data/fix/linux/elsa-2025-20663.md) | Oct 11, 2025 | | Linux | kernel-uek-container-debug ol 8 | 0:5.4.17-2136.348.3.el7uek | [ELSA-2025-20663](https://patchblox.com/security/data/fix/linux/elsa-2025-20663.md) | Oct 11, 2025 | | Linux | kernel-uek-debug ol 8 | 0:5.4.17-2136.348.3.el7uek | [ELSA-2025-20663](https://patchblox.com/security/data/fix/linux/elsa-2025-20663.md) | Oct 11, 2025 | | Linux | kernel-uek-debug-devel ol 8 | 0:5.4.17-2136.348.3.el7uek | [ELSA-2025-20663](https://patchblox.com/security/data/fix/linux/elsa-2025-20663.md) | Oct 11, 2025 | | Linux | kernel-uek-devel ol 8 | 0:5.4.17-2136.348.3.el7uek | [ELSA-2025-20663](https://patchblox.com/security/data/fix/linux/elsa-2025-20663.md) | Oct 11, 2025 | | Linux | kernel-uek-doc ol 8 | 0:5.4.17-2136.348.3.el7uek | [ELSA-2025-20663](https://patchblox.com/security/data/fix/linux/elsa-2025-20663.md) | Oct 11, 2025 | | Linux | kernel-uek-tools ol 8 | 0:5.4.17-2136.348.3.el7uek | [ELSA-2025-20663](https://patchblox.com/security/data/fix/linux/elsa-2025-20663.md) | Oct 11, 2025 | | Linux | linux Debian 12.15 (bookworm) | 6.1.153-1 | [DEBIAN-CVE-2025-39736](https://patchblox.com/security/data/fix/linux/debian-cve-2025-39736.md) | Sep 11, 2025 | | Linux | linux Debian 13.5 (trixie) | 6.12.43-1 | [DEBIAN-CVE-2025-39736](https://patchblox.com/security/data/fix/linux/debian-cve-2025-39736.md) | Sep 11, 2025 | | Linux | linux Debian 14 | 6.16.3-1 | [DEBIAN-CVE-2025-39736](https://patchblox.com/security/data/fix/linux/debian-cve-2025-39736.md) | Sep 11, 2025 | | Linux | perf amzn 2023 | 1:6.1.150-174.273.amzn2023 | [ALAS2023-2025-1186](https://patchblox.com/security/data/fix/linux/alas2023-2025-1186.md) | Sep 10, 2025 | | Linux | perf-debuginfo amzn 2023 | 1:6.1.150-174.273.amzn2023 | [ALAS2023-2025-1186](https://patchblox.com/security/data/fix/linux/alas2023-2025-1186.md) | Sep 10, 2025 | | Linux | python3-perf amzn 2023 | 1:6.1.150-174.273.amzn2023 | [ALAS2023-2025-1186](https://patchblox.com/security/data/fix/linux/alas2023-2025-1186.md) | Sep 10, 2025 | | Linux | python3-perf-debuginfo amzn 2023 | 1:6.1.150-174.273.amzn2023 | [ALAS2023-2025-1186](https://patchblox.com/security/data/fix/linux/alas2023-2025-1186.md) | Sep 10, 2025 | --- Data as of 2026-11-08T00:53:09Z UTC. 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