A bug in the Linux kernel’s IEEE 802.15.4 ca8210 driver causes a pointer truncation when data is written to and read from a kernel FIFO on 64‑bit architectures. The driver writes only the low 4 bytes of a 64‑bit pointer, then reads those 4 bytes into an 8‑byte variable, leaving the upper half uninitialized. When that partially constructed pointer is dereferenced, the kernel accesses a random kernel address, normally triggering an oops. Based on the description, the likely impact is kernel memory corruption that may lead to a system crash, representing a denial‑of‑service condition.

The vulnerability affects the Linux kernel on any 64‑bit build that has the ca8210 driver compiled with CONFIG_IEEE802154_CA8210_DEBUGFS=y. The driver was added in 2017 and has no architecture restrictions in the Kconfig, so every 64‑bit kernel that exposes the debugfs interface for this driver is vulnerable. No specific kernel release is listed, so administrators should treat all current releases as potentially impacted until the patch is applied.

The CVSS score is 5.5, and the EPSS score is <1%. The exploit requires the attacker to have write access to the debugfs interface of the ca8210 driver and to be able to supply a specially crafted write. This limits the attack surface to local users or compromised processes with debugfs permissions. The likely attack vector is local via the debugfs interface; this inference is based on the description. The result of exploitation is a kernel oops leading to a system crash, which is a form of denial of service. The vulnerability is not listed in CISA’s KEV catalog, but given its nature it should be treated as high risk until mitigated.