Answer in brief
CVE-2026-72071 records a High severity (CVSS 7.8) vulnerability in tracing/user_events: Fix use-after-free in user_event_mm_dup(). The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 7.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=7235759084a4f8524a46bd2638885ff3b34ce279 <25acb6711da6fa0382744fa92bd6d42a22c1ae68 || >=7235759084a4f8524a46bd2638885ff3b34ce279 <95400e7039cdfeb0b53652d521d766f1698cae95 || >=7235759084a4f8524a46bd2638885ff3b34ce279 <b33ac2d39953efb12f598c0dae242c5f644ea669 || >=7235759084a4f8524a46bd2638885ff3b34ce279 <05b24f68f78ff3a1ef7f015f7327b35886b741f6 || >=7235759084a4f8524a46bd2638885ff3b34ce279 <50fd6dd755c6e48a38af2fa4621167eea56829c2 | 25acb6711da6fa0382744fa92bd6d42a22c1ae68, 95400e7039cdfeb0b53652d521d766f1698cae95, b33ac2d39953efb12f598c0dae242c5f644ea669, 05b24f68f78ff3a1ef7f015f7327b35886b741f6, 50fd6dd755c6e48a38af2fa4621167eea56829c2 |
| Linux/Linuxgeneric | 6.4 | Not reported |
Published upstream
Aug 15, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 17, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 15, 2026
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.
Quoted source text, attributed separately from HOL analysis.