CVE-2024-38634: serial: max3100: Lock port->lock when calling uart_handle_cts_change()

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: 2024-06-21 · updated 2026-06-17
Weakness: CWE-667

Description

In the Linux kernel, the following vulnerability has been resolved: serial: max3100: Lock port->lock when calling uart_handle_cts_change() uart_handle_cts_change() has to be called with port lock taken, Since we run it in a separate work, the lock may not be taken at the time of running. Make sure that it's taken by explicitly doing that. Without it we got a splat: WARNING: CPU: 0 PID: 10 at drivers/tty/serial/serial_core.c:3491 uart_handle_cts_change+0xa6/0xb0 ... Workqueue: max3100-0 max3100_work [max3100] RIP: 0010:uart_handle_cts_change+0xa6/0xb0 ... max3100_handlerx+0xc5/0x110 [max3100] max3100_work+0x12a/0x340 [max3100]

Affected products

Linux kernel: from 2.6.31 before 4.19.316; from 4.20 before 5.4.278; from 5.5 before 5.10.219; from 5.11 before 5.15.161; from 5.16 before 6.1.93; from 6.2 before 6.6.33 — fixed in 4.19.316, 5.10.219, 5.15.161, 5.4.278, 6.1.93, 6.6.33

How to fix

Upgrade to a fixed version: Linux kernel 4.19.316, 5.10.219, 5.15.161, 5.4.278. Check the vendor advisory for mitigations.

References

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