Executive brief
A vulnerability in the Linux kernel's STM32 DMA multiplexer driver could lead to a resource leak. This component manages data transfers between hardware peripherals and memory in systems using STM32 processors. If exploited, this could allow a local user to cause a system-wide denial of service by exhausting available system resources.
Technical details
A reference counting error exists in the stm32-dmamux driver within the Linux kernel. Specifically, the stm32_dmamux_route_allocate function fails to drop a reference to the DMA mux platform device after looking it up. This results in a device reference leak (CWE-401). An attacker with local access could repeatedly trigger route allocations to exhaust system resources, eventually leading to a denial of service. The issue has been patched in multiple stable branches of the Linux kernel, including 5.10.249, 5.15.199, 6.1.162, 6.6.122, 6.12.67, and 6.18.7.
Affected products
- Linux Linux Kernel 4.15 to 5.10.249, 5.11 to 5.15.199, 5.16 to 6.1.162, 6.2 to 6.6.122, 6.7 to 6.12.67, 6.13 to 6.18.7
Timeline
- 2025-01-21: patched: Initial patch authored by Johan Hovold
- 2026-01-31: disclosed: CVE published by kernel.org
- 2026-03-25: advisory: NVD enrichment and analysis completed
References
- https://git.kernel.org/stable/c/1a179ac01ff3993ab97e33cc77c316ed7415cda1
- https://git.kernel.org/stable/c/1dda2a32303df0091896b01a9d09070d61fa344c
- https://git.kernel.org/stable/c/2fb10259d4efb4367787b5ae9c94192e8a91c648
- https://git.kernel.org/stable/c/3b42020e6790a5e19b36c187ed5b488a5716f97f
- https://git.kernel.org/stable/c/3ef52d31cce8ba816739085a61efe07b63c6cf27
- https://git.kernel.org/stable/c/6393da54dcb3488c080a183c4182ddec71ba8d7f
- https://git.kernel.org/stable/c/dd6e4943889fb354efa3f700e42739da9bddb6ef