# CVE-2026-46121: mm/damon/sysfs-schemes: protect memcg_path kfree() with damon_sysfs_lock CVE-2026-46121 is fixed in 50 products on 1 platform, first by ALAS2023-2026-1753, released May 25, 2026. It is not reported as exploited. Patch Radar priority: High. - Web page: https://patchblox.com/security/cve/CVE-2026-46121 - Priority: High - CVSS: 7.8 (Moderate) - EPSS: 0.0013 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: May 25, 2026 - Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-46121 ## Description In the Linux kernel, the following vulnerability has been resolved: mm/damon/sysfs-schemes: protect memcg_path kfree() with damon_sysfs_lock Patch series "mm/damon/sysfs-schemes: fix use-after-free for [memcg_]path". Reads of 'memcg_path' and 'path' files in DAMON sysfs interface could race with their writes, results in use-after-free. Fix those. This patch (of 2): damon_sysfs_scheme_filter->mmecg_path can be read and written by users, via DAMON sysfs memcg_path file. It can also be indirectly read, for the parameters {on,off}line committing to DAMON. The reads for parameters committing are protected by damon_sysfs_lock to avoid the sysfs files being destroyed while any of the parameters are being read. But the user-driven direct reads and writes are not protected by any lock, while the write is deallocating the memcg_path-pointing buffer. As a result, the readers could read the already freed buffer (user-after-free). Note that the user-reads don't race when the same open file is used by the writer, due to kernfs's open file locking. Nonetheless, doing the reads and writes with separate open files would be common. Fix it by protecting both the user-direct reads and writes with damon_sysfs_lock. ## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Linux | bpftool6.12 amzn 2023 | 1:6.12.88-119.157.amzn2023 | [ALAS2023-2026-1753](https://patchblox.com/security/data/fix/linux/alas2023-2026-1753.md) | May 25, 2026 | | Linux | bpftool6.12-debuginfo amzn 2023 | 1:6.12.88-119.157.amzn2023 | [ALAS2023-2026-1753](https://patchblox.com/security/data/fix/linux/alas2023-2026-1753.md) | May 25, 2026 | | Linux | bpftool6.18 amzn 2023 | 1:6.18.30-61.116.amzn2023 | [ALAS2023-2026-1754](https://patchblox.com/security/data/fix/linux/alas2023-2026-1754.md) | May 25, 2026 | | Linux | bpftool6.18-debuginfo amzn 2023 | 1:6.18.30-61.116.amzn2023 | [ALAS2023-2026-1754](https://patchblox.com/security/data/fix/linux/alas2023-2026-1754.md) | May 25, 2026 | | Linux | dtb-aarch64 opensuse-leap 16.0 | 6.12.0-160000.37.1 | [OPENSUSE-SU-2026:21555-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21555-1.md) | Aug 12, 2026 | | Linux | kernel-64kb opensuse-leap 16.0 | 6.12.0-160000.37.1 | [OPENSUSE-SU-2026:21555-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21555-1.md) | Aug 12, 2026 | | Linux | kernel-64kb sles 16.0 | 6.12.0-160000.37.1 | [SUSE-SU-2026:23231-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23231-1.md) | Aug 11, 2026 | | Linux | kernel-azure opensuse-leap 16.0 | 6.12.0-160000.37.1 | [OPENSUSE-SU-2026:21555-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21555-1.md) | Aug 12, 2026 | | Linux | kernel-azure sles 16.0 | 6.12.0-160000.37.1 | [SUSE-SU-2026:23231-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23231-1.md) | Aug 11, 2026 | | Linux | kernel-default opensuse-leap 16.0 | 6.12.0-160000.37.1 | [OPENSUSE-SU-2026:21555-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21555-1.md) | Aug 12, 2026 | | Linux | kernel-default sles 16.0 | 6.12.0-160000.37.1 | [SUSE-SU-2026:23237-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23237-1.md) | Aug 11, 2026 | | Linux | kernel-default-base opensuse-leap 16.0 | 6.12.0-160000.37.1.160000.2.19 | [OPENSUSE-SU-2026:21555-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21555-1.md) | Aug 12, 2026 | | Linux | kernel-default-base sles 16.0 | 6.12.0-160000.37.1.160000.2.19 | [SUSE-SU-2026:23231-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23231-1.md) | Aug 11, 2026 | | Linux | kernel-docs opensuse-leap 16.0 | 6.12.0-160000.37.1 | [OPENSUSE-SU-2026:21555-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21555-1.md) | Aug 12, 2026 | | Linux | kernel-docs sles 16.0 | 6.12.0-160000.37.1 | [SUSE-SU-2026:23231-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23231-1.md) | Aug 11, 2026 | | Linux | kernel-kvmsmall opensuse-leap 16.0 | 6.12.0-160000.37.1 | [OPENSUSE-SU-2026:21555-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21555-1.md) | Aug 12, 2026 | | Linux | kernel-kvmsmall sles 16.0 | 6.12.0-160000.37.1 | [SUSE-SU-2026:23231-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23231-1.md) | Aug 11, 2026 | | Linux | kernel-livepatch-6.12.88-119.157 amzn 2023 | 1:1.0-0.amzn2023 | [ALAS2023-2026-1753](https://patchblox.com/security/data/fix/linux/alas2023-2026-1753.md) | May 25, 2026 | | Linux | kernel-livepatch-6.18.30-61.116 amzn 2023 | 1:1.0-0.amzn2023 | [ALAS2023-2026-1754](https://patchblox.com/security/data/fix/linux/alas2023-2026-1754.md) | May 25, 2026 | | Linux | kernel-obs-build opensuse-leap 16.0 | 6.12.0-160000.37.1 | [OPENSUSE-SU-2026:21555-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21555-1.md) | Aug 12, 2026 | | Linux | kernel-obs-qa opensuse-leap 16.0 | 6.12.0-160000.37.1 | [OPENSUSE-SU-2026:21555-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21555-1.md) | Aug 12, 2026 | | Linux | kernel-obs-qa sles 16.0 | 6.12.0-160000.37.1 | [SUSE-SU-2026:23231-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23231-1.md) | Aug 11, 2026 | | Linux | kernel-rt opensuse-leap 16.0 | 6.12.0-160000.37.1 | [OPENSUSE-SU-2026:21555-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21555-1.md) | Aug 12, 2026 | | Linux | kernel-source opensuse-leap 16.0 | 6.12.0-160000.37.1 | [OPENSUSE-SU-2026:21555-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21555-1.md) | Aug 12, 2026 | | Linux | kernel-source sles 16.0 | 6.12.0-160000.37.1 | [SUSE-SU-2026:23231-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23231-1.md) | Aug 11, 2026 | | Linux | kernel-syms opensuse-leap 16.0 | 6.12.0-160000.37.1 | [OPENSUSE-SU-2026:21555-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21555-1.md) | Aug 12, 2026 | | Linux | kernel-syms sles 16.0 | 6.12.0-160000.37.1 | [SUSE-SU-2026:23231-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23231-1.md) | Aug 11, 2026 | | Linux | kernel-zfcpdump opensuse-leap 16.0 | 6.12.0-160000.37.1 | [OPENSUSE-SU-2026:21555-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21555-1.md) | Aug 12, 2026 | | Linux | kernel-zfcpdump sles 16.0 | 6.12.0-160000.37.1 | [SUSE-SU-2026:23231-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23231-1.md) | Aug 11, 2026 | | Linux | kernel6.12 amzn 2023 | 1:6.12.88-119.157.amzn2023 | [ALAS2023-2026-1753](https://patchblox.com/security/data/fix/linux/alas2023-2026-1753.md) | May 25, 2026 | | Linux | kernel6.12-debuginfo amzn 2023 | 1:6.12.88-119.157.amzn2023 | [ALAS2023-2026-1753](https://patchblox.com/security/data/fix/linux/alas2023-2026-1753.md) | May 25, 2026 | | Linux | kernel6.12-debuginfo-common-aarch64 amzn 2023 | 1:6.12.88-119.157.amzn2023 | [ALAS2023-2026-1753](https://patchblox.com/security/data/fix/linux/alas2023-2026-1753.md) | May 25, 2026 | | Linux | kernel6.12-debuginfo-common-x86_64 amzn 2023 | 1:6.12.88-119.157.amzn2023 | [ALAS2023-2026-1753](https://patchblox.com/security/data/fix/linux/alas2023-2026-1753.md) | May 25, 2026 | | Linux | kernel6.12-devel amzn 2023 | 1:6.12.88-119.157.amzn2023 | [ALAS2023-2026-1753](https://patchblox.com/security/data/fix/linux/alas2023-2026-1753.md) | May 25, 2026 | | Linux | kernel6.12-headers amzn 2023 | 1:6.12.88-119.157.amzn2023 | [ALAS2023-2026-1753](https://patchblox.com/security/data/fix/linux/alas2023-2026-1753.md) | May 25, 2026 | | Linux | kernel6.12-modules-extra amzn 2023 | 1:6.12.88-119.157.amzn2023 | [ALAS2023-2026-1753](https://patchblox.com/security/data/fix/linux/alas2023-2026-1753.md) | May 25, 2026 | | Linux | kernel6.12-modules-extra-common amzn 2023 | 1:6.12.88-119.157.amzn2023 | [ALAS2023-2026-1753](https://patchblox.com/security/data/fix/linux/alas2023-2026-1753.md) | May 25, 2026 | | Linux | kernel6.12-tools amzn 2023 | 1:6.12.88-119.157.amzn2023 | [ALAS2023-2026-1753](https://patchblox.com/security/data/fix/linux/alas2023-2026-1753.md) | May 25, 2026 | | Linux | kernel6.12-tools-debuginfo amzn 2023 | 1:6.12.88-119.157.amzn2023 | [ALAS2023-2026-1753](https://patchblox.com/security/data/fix/linux/alas2023-2026-1753.md) | May 25, 2026 | | Linux | kernel6.12-tools-devel amzn 2023 | 1:6.12.88-119.157.amzn2023 | [ALAS2023-2026-1753](https://patchblox.com/security/data/fix/linux/alas2023-2026-1753.md) | May 25, 2026 | | Linux | kernel6.18 amzn 2023 | 1:6.18.30-61.116.amzn2023 | [ALAS2023-2026-1754](https://patchblox.com/security/data/fix/linux/alas2023-2026-1754.md) | May 25, 2026 | | Linux | kernel6.18-debuginfo amzn 2023 | 1:6.18.30-61.116.amzn2023 | [ALAS2023-2026-1754](https://patchblox.com/security/data/fix/linux/alas2023-2026-1754.md) | May 25, 2026 | | Linux | kernel6.18-debuginfo-common-aarch64 amzn 2023 | 1:6.18.30-61.116.amzn2023 | [ALAS2023-2026-1754](https://patchblox.com/security/data/fix/linux/alas2023-2026-1754.md) | May 25, 2026 | | Linux | kernel6.18-debuginfo-common-x86_64 amzn 2023 | 1:6.18.30-61.116.amzn2023 | [ALAS2023-2026-1754](https://patchblox.com/security/data/fix/linux/alas2023-2026-1754.md) | May 25, 2026 | | Linux | kernel6.18-devel amzn 2023 | 1:6.18.30-61.116.amzn2023 | [ALAS2023-2026-1754](https://patchblox.com/security/data/fix/linux/alas2023-2026-1754.md) | May 25, 2026 | | Linux | kernel6.18-headers amzn 2023 | 1:6.18.30-61.116.amzn2023 | [ALAS2023-2026-1754](https://patchblox.com/security/data/fix/linux/alas2023-2026-1754.md) | May 25, 2026 | | Linux | kernel6.18-modules-extra amzn 2023 | 1:6.18.30-61.116.amzn2023 | [ALAS2023-2026-1754](https://patchblox.com/security/data/fix/linux/alas2023-2026-1754.md) | May 25, 2026 | | Linux | kernel6.18-modules-extra-common amzn 2023 | 1:6.18.30-61.116.amzn2023 | [ALAS2023-2026-1754](https://patchblox.com/security/data/fix/linux/alas2023-2026-1754.md) | May 25, 2026 | | Linux | kernel6.18-tools amzn 2023 | 1:6.18.30-61.116.amzn2023 | [ALAS2023-2026-1754](https://patchblox.com/security/data/fix/linux/alas2023-2026-1754.md) | May 25, 2026 | | Linux | kernel6.18-tools-debuginfo amzn 2023 | 1:6.18.30-61.116.amzn2023 | [ALAS2023-2026-1754](https://patchblox.com/security/data/fix/linux/alas2023-2026-1754.md) | May 25, 2026 | | Linux | kernel6.18-tools-devel amzn 2023 | 1:6.18.30-61.116.amzn2023 | [ALAS2023-2026-1754](https://patchblox.com/security/data/fix/linux/alas2023-2026-1754.md) | May 25, 2026 | | Linux | linux Debian 13.5 (trixie) | 6.12.88-1 | [DEBIAN-CVE-2026-46121](https://patchblox.com/security/data/fix/linux/debian-cve-2026-46121.md) | Jun 24, 2026 | | Linux | linux Debian 14 | 7.0.7-1 | [DEBIAN-CVE-2026-46121](https://patchblox.com/security/data/fix/linux/debian-cve-2026-46121.md) | Jun 24, 2026 | | Linux | perf6.12 amzn 2023 | 1:6.12.88-119.157.amzn2023 | [ALAS2023-2026-1753](https://patchblox.com/security/data/fix/linux/alas2023-2026-1753.md) | May 25, 2026 | | Linux | perf6.12-debuginfo amzn 2023 | 1:6.12.88-119.157.amzn2023 | [ALAS2023-2026-1753](https://patchblox.com/security/data/fix/linux/alas2023-2026-1753.md) | May 25, 2026 | | Linux | perf6.18 amzn 2023 | 1:6.18.30-61.116.amzn2023 | [ALAS2023-2026-1754](https://patchblox.com/security/data/fix/linux/alas2023-2026-1754.md) | May 25, 2026 | | Linux | perf6.18-debuginfo amzn 2023 | 1:6.18.30-61.116.amzn2023 | [ALAS2023-2026-1754](https://patchblox.com/security/data/fix/linux/alas2023-2026-1754.md) | May 25, 2026 | | Linux | python3-perf6.12 amzn 2023 | 1:6.12.88-119.157.amzn2023 | [ALAS2023-2026-1753](https://patchblox.com/security/data/fix/linux/alas2023-2026-1753.md) | May 25, 2026 | | Linux | python3-perf6.12-debuginfo amzn 2023 | 1:6.12.88-119.157.amzn2023 | [ALAS2023-2026-1753](https://patchblox.com/security/data/fix/linux/alas2023-2026-1753.md) | May 25, 2026 | | Linux | python3-perf6.18 amzn 2023 | 1:6.18.30-61.116.amzn2023 | [ALAS2023-2026-1754](https://patchblox.com/security/data/fix/linux/alas2023-2026-1754.md) | May 25, 2026 | | Linux | python3-perf6.18-debuginfo amzn 2023 | 1:6.18.30-61.116.amzn2023 | [ALAS2023-2026-1754](https://patchblox.com/security/data/fix/linux/alas2023-2026-1754.md) | May 25, 2026 | --- Data as of 2026-11-08T00:53:09Z UTC. 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