Technical impact
The race condition is triggered when tty_port_link_device is omitted before uart_configure_port, allowing a user‑space process to open the serial console during the boot sequence. The kernel then attempts to initialize the console with an uninitialized tty->port reference, which causes an immediate kernel panic. This soft‑fail path results in a local denial‑of‑service that requires no network involvement but demands the ability to access the console device, typically root or a privileged user. The flaw is a classic example of a race condition (CWE‑362).
Affected Systems
The bug is present in the Linux kernel 6.19 release series before the recent commit that re‑established tty_port_link_device. The affected releases are the rc1 through rc6 snapshots and any downstream patches that did not cherry‑pick the fix. Devices that use a Qualcomm SoC with a serial port configured as the boot console are the most likely to hit the error, but any system that links a serial console without first setting tty->port is vulnerable. The vulnerability applies to the generic Linux kernel; there is no vendor‑specific product beyond the kernel itself.
Risk and Exploitability
With a CVSS base score of 4.7 the vulnerability poses moderate impact; the availability metric is high. The EPSS score of less than 1 % indicates a low probability of exploitation, and the feature is not listed in the CISA KEV catalog. The attack vector is local user space. An attacker with the ability to open the console device during the very early boot phase can trigger the race and force the kernel to crash, disrupting all services. Because the condition is self‑applied at boot, it does not enable privilege escalation or data theft; the result is limited to denial‑of‑service.
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