Executive brief
A vulnerability in the Linux kernel's VUB300 USB-to-SD driver can cause a system crash when a device is disconnected. This affects systems using specific SD/MMC hardware interfaces, including certain industrial Siemens controllers. An attacker with local access could exploit this to cause a denial-of-service, potentially disrupting operations or industrial processes.
Technical details
A race condition or improper cleanup sequence exists in the vub300_disconnect function within drivers/mmc/host/vub300.c. The driver was dropping its reference to driver data (kref_put) before deregistering the MMC host (mmc_remove_host), leading to a NULL pointer dereference or use-after-free if the host was accessed during the teardown process. A local attacker can trigger this by initiating a device disconnect, resulting in a kernel oops and denial of service. Patches have been backported to multiple stable kernel branches (3.0+).
Affected products
- Linux Linux Kernel 3.0 to 6.14
- Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP V3.1.5, V3.1.6
Timeline
- 2026-03-27: other: Patch authored by Johan Hovold
- 2026-04-24: disclosed: CVE published
References
- https://git.kernel.org/stable/c/517b58e1d067115f80d198feee10192da4c424d0
- https://git.kernel.org/stable/c/53f2642d77ab5f1f303388bff5500363c6cf962c
- https://git.kernel.org/stable/c/6446516e626ce7c44bdadbcbb3d7677a2c52ce93
- https://git.kernel.org/stable/c/6468cab1173f44f7a4b7a05ce8abfdfd1ce1557a
- https://git.kernel.org/stable/c/8d09e75759cb2afc0732acfb5a14a93c03805a61
- https://git.kernel.org/stable/c/ba3b9429de94958dc0060d9816a915dd75c34919
- https://git.kernel.org/stable/c/c83a282615d8f7ba28cebddd54600b419d562d82