A use‑after‑free flaw exists in the Linux kernel’s serial CAIF line discipline. The missing reference to tty->link during ldisc_open and ser_release causes a KASAN‑detected UAF when caif_serial’s TX path invokes tty_write_room, potentially enabling an attacker to corrupt kernel memory or execute arbitrary code with elevated privileges. The weakness is a classic use‑after‑free error (CWE‑416) and involves memory reference misuse (CWE‑911).

The affected product is the Linux kernel. All kernel releases prior to the application of the fix that introduces an extra kref on tty->link are vulnerable. No specific version range is listed; any kernel containing the buggy caif_serial line discipline may be impacted.

An EPSS score of < 1% indicates a low probability of exploitation, but the high CVSS score of 7.8 classifies the flaw as a high‑severity kernel memory corruption vulnerability. The flaw can lead to arbitrary code execution if an attacker can trigger a use‑after‑free in the CAIF serial line discipline. The vulnerability is not listed in the CISA KEV catalog. The likely attack vector involves interacting with a serial CAIF device from user space, possibly locally or remotely if the device is exposed over a network or shared environment.