Executive brief
A memory leak vulnerability was identified in the Linux kernel's MMIO multiplexer driver. This component is responsible for managing hardware signals that allow multiple data streams to share a single resource. An exploit could lead to a gradual depletion of system memory, potentially causing system instability or a denial-of-service condition.
Technical details
A memory leak (CWE-401) exists in drivers/mux/mmio.c within the Linux kernel. The vulnerability occurs because the mmio regmap allocated during the driver's probe phase is never explicitly freed. This leak can be triggered during probe failures (such as probe deferral) or during driver unbinding. An attacker with local access could potentially exploit this to cause a denial-of-service through memory exhaustion. The fix involves migrating to the device-managed allocator (devm_regmap_init_mmio), which ensures the regmap is automatically released. Patches have been backported to various stable kernel branches.
Affected products
- Linux Linux kernel 6.16 to 6.18.16, 6.19 to 6.19.6
Timeline
- 2025-11-27: other: Patch authored
- 2026-05-06: disclosed: CVE published
- 2026-05-06: advisory