CVE-2025-37878
Vulnérabilité non évaluée dans Linux (Linux)
Description
In the Linux kernel, the following vulnerability has been resolved: perf/core: Fix WARN_ON(!ctx) in __free_event() for partial init Move the get_ctx(child_ctx) call and the child_event->ctx assignment to occur immediately after the child event is allocated. Ensure that child_event->ctx is non-NULL before any subsequent error path within inherit_event calls free_event(), satisfying the assumptions of the cleanup code. Details: There's no clear Fixes tag, because this bug is a side-effect of multiple interacting commits over time (up to 15 years old), not a single regression. The code initially incremented refcount then assigned context immediately after the child_event was created. Later, an early validity check for child_event was added before the refcount/assignment. Even later, a WARN_ON_ONCE() cleanup check was added, assuming event->ctx is valid if the pmu_ctx is valid. The problem is that the WARN_ON_ONCE() could trigger after the initial check passed but before child_event->ctx was assigned, violating its precondition. The solution is to assign child_event->ctx right after its initial validation. This ensures the context exists for any subsequent checks or cleanup routines, resolving the WARN_ON_ONCE(). To resolve it, defer the refcount update and child_event->ctx assignment directly after child_event->pmu_ctx is set but before checking if the parent event is orphaned. The cleanup routine depends on event->pmu_ctx being non-NULL before it verifies event->ctx is non-NULL. This also maintains the author's original intent of passing in child_ctx to find_get_pmu_context before its refcount/assignment. [ mingo: Expanded the changelog from another email by Gabriel Shahrouzi. ]
Gravité et risque d'exploitation
CVE-2025-37878 obtient un score CVSS de 0.0/10, soit une gravité non évaluée. Selon le modèle EPSS, la probabilité qu'elle soit exploitée dans les 30 prochains jours est de 0.28 %, ce qui la place devant 18.8 % des CVE référencées.
Que faire ?
- Vérifiez si Linux (versions <90dc6c1e3b200812da8d0aa030e1b7fda8226d0e, 1209b0b29fd472e7dbd2b06544b019dd9f9b7e51, <6.14.5, c70ca298036c58a88686ff388d3d367e9d21acf0, <6.14, 6.14.3, <6.12.26, 315a50c6b1c6ce191f19f3372935d8e2ed9b53a6, 6.12.24, <cb56cd11feabf99e08bc18960700a53322ffcea7, <0ba3a4ab76fd3367b9cb680cad70182c896c795c, 7ef5aa081f989ecfecc1df02068a80aebbd3ec31, 6.13.12) est présent sur votre parc.
- Appliquez le correctif ou la version corrigée indiqués dans les références de l'éditeur.
- À défaut de correctif, limitez l'exposition (filtrage réseau, désactivation du composant).
- Automatisez la détection : les agents CVE Heimdall (gratuits, open source) corrèlent l'inventaire de vos serveurs avec la base CVE.