CVE-2024-50058: serial: protect uart_port_dtr_rts() in uart_shutdown() too

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-10-21 · updated 2026-10-15
Weakness: CWE-476

Description

In the Linux kernel, the following vulnerability has been resolved: serial: protect uart_port_dtr_rts() in uart_shutdown() too Commit af224ca2df29 (serial: core: Prevent unsafe uart port access, part 3) added few uport == NULL checks. It added one to uart_shutdown(), so the commit assumes, uport can be NULL in there. But right after that protection, there is an unprotected "uart_port_dtr_rts(uport, false);" call. That is invoked only if HUPCL is set, so I assume that is the reason why we do not see lots of these reports. Or it cannot be NULL at this point at all for some reason :P. Until the above is investigated, stay on the safe side and move this dereference to the if too. I got this inconsistency from Coverity under CID 1585130. Thanks.

Affected products

Linux kernel: before 6.6.57; from 6.7 before 6.11.4 — fixed in 6.11.4, 6.6.57

How to fix

Upgrade to a fixed version: Linux kernel 6.11.4, 6.6.57. Check the vendor advisory for mitigations.

References

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