Description

In the Linux kernel, the following vulnerability has been resolved: serial: max3100: Update uart_driver_registered on driver removal The removal of the last MAX3100 device triggers the removal of the driver. However, code doesn't update the respective global variable and after insmod — rmmod — insmod cycle the kernel oopses: max3100 spi-PRP0001:01: max3100_probe: adding port 0 BUG: kernel NULL pointer dereference, address: 0000000000000408 ... RIP: 0010:serial_core_register_port+0xa0/0x840 ... max3100_probe+0x1b6/0x280 [max3100] spi_probe+0x8d/0xb0 Update the actual state so next time UART driver will be registered again. Hugo also noticed, that the error path in the probe also affected by having the variable set, and not cleared. Instead of clearing it move the assignment after the successfull uart_register_driver() call.

Severity MEDIUM

CVSS Score 5.5

CVSS Vector CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CWE CWE-476

Public Exploit ✅ No

Source NVD

Published 2024-06-21

Updated 2026-06-02

Modified 2025-11-04

Fix URL https://git.kernel.org/stable/c/21a61a7fbcfdd3493cede43ebc7c4dfae2147a8b

Software	From version	Fixed in
linux-kernel	6.7	6.9.4