CVE-2021-47073: platform/x86: dell-smbios-wmi: Fix oops on rmmod dell_smbios

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: 2024-03-01 · updated 2026-06-17

Description

In the Linux kernel, the following vulnerability has been resolved: platform/x86: dell-smbios-wmi: Fix oops on rmmod dell_smbios init_dell_smbios_wmi() only registers the dell_smbios_wmi_driver on systems where the Dell WMI interface is supported. While exit_dell_smbios_wmi() unregisters it unconditionally, this leads to the following oops: [ 175.722921] ------------[ cut here ]------------ [ 175.722925] Unexpected driver unregister! [ 175.722939] WARNING: CPU: 1 PID: 3630 at drivers/base/driver.c:194 driver_unregister+0x38/0x40 ... [ 175.723089] Call Trace: [ 175.723094] cleanup_module+0x5/0xedd [dell_smbios] ... [ 175.723148] ---[ end trace 064c34e1ad49509d ]--- Make the unregister happen on the same condition the register happens to fix this.

Affected products

Linux kernel: from 4.15 before 4.19.192; from 4.20 before 5.4.122; from 5.5 before 5.10.40; from 5.11 before 5.12.7; 5.13-rc1, 5.13-rc2 — fixed in 4.19.192, 5.10.40, 5.12.7, 5.4.122

How to fix

Upgrade to a fixed version: Linux kernel 4.19.192, 5.10.40, 5.12.7, 5.4.122. Check the vendor advisory for mitigations.

References

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