# CVE-2026-72071: linux: In the Linux kernel, the following vulnerability has been resolved: tracing/user_events: Fix use-after-free in user_... CVE-2026-72071 is fixed in 38 products on 1 platform, first by DEBIAN-CVE-2026-72071, released August 15, 2026. It is not reported as exploited. Patch Radar priority: High. - Web page: https://patchblox.com/security/cve/CVE-2026-72071 - Priority: High - CVSS: 7.8 (high) - EPSS: 0.0017 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: Aug 15, 2026 ## Description In the Linux kernel, the following vulnerability has been resolved: tracing/user_events: Fix use-after-free in user_event_mm_dup() user_event_mm_dup() walks the parent mm's enabler list locklessly under rcu_read_lock() during fork() (from copy_process()); it does not take event_mutex: rcu_read_lock(); list_for_each_entry_rcu(enabler, &old_mm->enablers, mm_enablers_link) enabler->event = user_event_get(orig->event); user_event_enabler_destroy() removes an enabler from that list with list_del_rcu() and then, without waiting for a grace period, drops the enabler's user_event reference with user_event_put() and frees the enabler with kfree(). A reader that loaded the enabler before the list_del_rcu() can still be walking it, which leads to two use-after-frees: - kfree(enabler) frees the enabler while that reader dereferences enabler->event. - user_event_put() may drop the last reference to the user_event, which is then freed (via delayed_destroy_user_event() on a work queue), while the same reader does user_event_get(orig->event) on it. Both are reachable by an unprivileged task that can open user_events_data: one multithreaded process that registers an enabler and then concurrently unregisters it and calls fork() triggers the race. KASAN reports a slab-use-after-free in user_event_mm_dup() during clone(), with a "refcount_t: addition on 0" warning when the user_event is freed. The enabler use-after-free was found first; the user_event one was reported by XIAO WU, and the earlier enabler-only fix did not address it. Defer both the user_event_put() and the kfree(enabler) to a work item queued with queue_rcu_work(), so they run only after an RCU grace period, once all readers walking the enabler list have finished. The put must run in process context because user_event_put() takes event_mutex on the last reference, so a work queue is used rather than call_rcu(). The now-unlocked put lets the locked argument of user_event_enabler_destroy() be removed; all callers are updated. ## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Linux | bpftool6.12 amzn 2023 | 1:6.12.100-125.179.amzn2023 | [ALAS2023-2026-2057](https://patchblox.com/security/data/fix/linux/alas2023-2026-2057.md) | Aug 17, 2026 | | Linux | bpftool6.12-debuginfo amzn 2023 | 1:6.12.100-125.179.amzn2023 | [ALAS2023-2026-2057](https://patchblox.com/security/data/fix/linux/alas2023-2026-2057.md) | Aug 17, 2026 | | Linux | bpftool6.18 amzn 2023 | 1:6.18.41-94.142.amzn2023 | [ALAS2023-2026-2071](https://patchblox.com/security/data/fix/linux/alas2023-2026-2071.md) | Aug 31, 2026 | | Linux | bpftool6.18-debuginfo amzn 2023 | 1:6.18.41-94.142.amzn2023 | [ALAS2023-2026-2071](https://patchblox.com/security/data/fix/linux/alas2023-2026-2071.md) | Aug 31, 2026 | | Linux | kernel-livepatch-6.12.100-125.179 amzn 2023 | 1:1.0-0.amzn2023 | [ALAS2023-2026-2057](https://patchblox.com/security/data/fix/linux/alas2023-2026-2057.md) | Aug 17, 2026 | | Linux | kernel-livepatch-6.18.41-94.142 amzn 2023 | 1:1.0-0.amzn2023 | [ALAS2023-2026-2071](https://patchblox.com/security/data/fix/linux/alas2023-2026-2071.md) | Aug 31, 2026 | | Linux | kernel6.12 amzn 2023 | 1:6.12.100-125.179.amzn2023 | [ALAS2023-2026-2057](https://patchblox.com/security/data/fix/linux/alas2023-2026-2057.md) | Aug 17, 2026 | | Linux | kernel6.12-debuginfo amzn 2023 | 1:6.12.100-125.179.amzn2023 | [ALAS2023-2026-2057](https://patchblox.com/security/data/fix/linux/alas2023-2026-2057.md) | Aug 17, 2026 | | Linux | kernel6.12-debuginfo-common-aarch64 amzn 2023 | 1:6.12.100-125.179.amzn2023 | [ALAS2023-2026-2057](https://patchblox.com/security/data/fix/linux/alas2023-2026-2057.md) | Aug 17, 2026 | | Linux | kernel6.12-debuginfo-common-x86_64 amzn 2023 | 1:6.12.100-125.179.amzn2023 | [ALAS2023-2026-2057](https://patchblox.com/security/data/fix/linux/alas2023-2026-2057.md) | Aug 17, 2026 | | Linux | kernel6.12-devel amzn 2023 | 1:6.12.100-125.179.amzn2023 | [ALAS2023-2026-2057](https://patchblox.com/security/data/fix/linux/alas2023-2026-2057.md) | Aug 17, 2026 | | Linux | kernel6.12-headers amzn 2023 | 1:6.12.100-125.179.amzn2023 | [ALAS2023-2026-2057](https://patchblox.com/security/data/fix/linux/alas2023-2026-2057.md) | Aug 17, 2026 | | Linux | kernel6.12-modules-extra amzn 2023 | 1:6.12.100-125.179.amzn2023 | [ALAS2023-2026-2057](https://patchblox.com/security/data/fix/linux/alas2023-2026-2057.md) | Aug 17, 2026 | | Linux | kernel6.12-modules-extra-common amzn 2023 | 1:6.12.100-125.179.amzn2023 | [ALAS2023-2026-2057](https://patchblox.com/security/data/fix/linux/alas2023-2026-2057.md) | Aug 17, 2026 | | Linux | kernel6.12-tools amzn 2023 | 1:6.12.100-125.179.amzn2023 | [ALAS2023-2026-2057](https://patchblox.com/security/data/fix/linux/alas2023-2026-2057.md) | Aug 17, 2026 | | Linux | kernel6.12-tools-debuginfo amzn 2023 | 1:6.12.100-125.179.amzn2023 | [ALAS2023-2026-2057](https://patchblox.com/security/data/fix/linux/alas2023-2026-2057.md) | Aug 17, 2026 | | Linux | kernel6.12-tools-devel amzn 2023 | 1:6.12.100-125.179.amzn2023 | [ALAS2023-2026-2057](https://patchblox.com/security/data/fix/linux/alas2023-2026-2057.md) | Aug 17, 2026 | | Linux | kernel6.18 amzn 2023 | 1:6.18.41-94.142.amzn2023 | [ALAS2023-2026-2071](https://patchblox.com/security/data/fix/linux/alas2023-2026-2071.md) | Aug 31, 2026 | | Linux | kernel6.18-debuginfo amzn 2023 | 1:6.18.41-94.142.amzn2023 | [ALAS2023-2026-2071](https://patchblox.com/security/data/fix/linux/alas2023-2026-2071.md) | Aug 31, 2026 | | Linux | kernel6.18-debuginfo-common-aarch64 amzn 2023 | 1:6.18.41-94.142.amzn2023 | [ALAS2023-2026-2071](https://patchblox.com/security/data/fix/linux/alas2023-2026-2071.md) | Aug 31, 2026 | | Linux | kernel6.18-debuginfo-common-x86_64 amzn 2023 | 1:6.18.41-94.142.amzn2023 | [ALAS2023-2026-2071](https://patchblox.com/security/data/fix/linux/alas2023-2026-2071.md) | Aug 31, 2026 | | Linux | kernel6.18-devel amzn 2023 | 1:6.18.41-94.142.amzn2023 | [ALAS2023-2026-2071](https://patchblox.com/security/data/fix/linux/alas2023-2026-2071.md) | Aug 31, 2026 | | Linux | kernel6.18-headers amzn 2023 | 1:6.18.41-94.142.amzn2023 | [ALAS2023-2026-2071](https://patchblox.com/security/data/fix/linux/alas2023-2026-2071.md) | Aug 31, 2026 | | Linux | kernel6.18-modules-extra amzn 2023 | 1:6.18.41-94.142.amzn2023 | [ALAS2023-2026-2071](https://patchblox.com/security/data/fix/linux/alas2023-2026-2071.md) | Aug 31, 2026 | | Linux | kernel6.18-modules-extra-common amzn 2023 | 1:6.18.41-94.142.amzn2023 | [ALAS2023-2026-2071](https://patchblox.com/security/data/fix/linux/alas2023-2026-2071.md) | Aug 31, 2026 | | Linux | kernel6.18-tools amzn 2023 | 1:6.18.41-94.142.amzn2023 | [ALAS2023-2026-2071](https://patchblox.com/security/data/fix/linux/alas2023-2026-2071.md) | Aug 31, 2026 | | Linux | kernel6.18-tools-debuginfo amzn 2023 | 1:6.18.41-94.142.amzn2023 | [ALAS2023-2026-2071](https://patchblox.com/security/data/fix/linux/alas2023-2026-2071.md) | Aug 31, 2026 | | Linux | kernel6.18-tools-devel amzn 2023 | 1:6.18.41-94.142.amzn2023 | [ALAS2023-2026-2071](https://patchblox.com/security/data/fix/linux/alas2023-2026-2071.md) | Aug 31, 2026 | | Linux | linux Debian 13.5 (trixie) | 6.12.100-1 | [DEBIAN-CVE-2026-72071](https://patchblox.com/security/data/fix/linux/debian-cve-2026-72071.md) | Aug 15, 2026 | | Linux | linux Debian 14 | 7.1.5-1 | [DEBIAN-CVE-2026-72071](https://patchblox.com/security/data/fix/linux/debian-cve-2026-72071.md) | Aug 15, 2026 | | Linux | microvm-kernel6.18 amzn 2023 | 1:6.18.41-94.142.amzn2023 | [ALAS2023-2026-2071](https://patchblox.com/security/data/fix/linux/alas2023-2026-2071.md) | Aug 31, 2026 | | Linux | perf6.12 amzn 2023 | 1:6.12.100-125.179.amzn2023 | [ALAS2023-2026-2057](https://patchblox.com/security/data/fix/linux/alas2023-2026-2057.md) | Aug 17, 2026 | | Linux | perf6.12-debuginfo amzn 2023 | 1:6.12.100-125.179.amzn2023 | [ALAS2023-2026-2057](https://patchblox.com/security/data/fix/linux/alas2023-2026-2057.md) | Aug 17, 2026 | | Linux | perf6.18 amzn 2023 | 1:6.18.41-94.142.amzn2023 | [ALAS2023-2026-2071](https://patchblox.com/security/data/fix/linux/alas2023-2026-2071.md) | Aug 31, 2026 | | Linux | perf6.18-debuginfo amzn 2023 | 1:6.18.41-94.142.amzn2023 | [ALAS2023-2026-2071](https://patchblox.com/security/data/fix/linux/alas2023-2026-2071.md) | Aug 31, 2026 | | Linux | python3-perf6.12 amzn 2023 | 1:6.12.100-125.179.amzn2023 | [ALAS2023-2026-2057](https://patchblox.com/security/data/fix/linux/alas2023-2026-2057.md) | Aug 17, 2026 | | Linux | python3-perf6.12-debuginfo amzn 2023 | 1:6.12.100-125.179.amzn2023 | [ALAS2023-2026-2057](https://patchblox.com/security/data/fix/linux/alas2023-2026-2057.md) | Aug 17, 2026 | | Linux | python3-perf6.18 amzn 2023 | 1:6.18.41-94.142.amzn2023 | [ALAS2023-2026-2071](https://patchblox.com/security/data/fix/linux/alas2023-2026-2071.md) | Aug 31, 2026 | | Linux | python3-perf6.18-debuginfo amzn 2023 | 1:6.18.41-94.142.amzn2023 | [ALAS2023-2026-2071](https://patchblox.com/security/data/fix/linux/alas2023-2026-2071.md) | Aug 31, 2026 | --- Data as of 2026-11-08T00:53:09Z UTC. 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