Senior LevelLinux Commands & SysAdmin
How does Linux Kernel Module Signing enforce Secure Boot integrity?
❓ Interview Prompt: Explain UEFI Secure Boot, Kernel Module Signing (CONFIG_MODULE_SIG), X.509 cryptographic signatures, and blocking untrusted rootkits.
When UEFI Secure Boot is enabled, the Linux kernel enforces Kernel Module Signing ('CONFIG_MODULE_SIG_FORCE') to prevent untrusted rootkits from loading into kernel memory:
Mechanism:
Every '.ko' kernel module file must be cryptographically signed with a trusted X.509 key. The kernel verifies the signature before execution; unsigned modules are immediately rejected!
Code Implementation Example
bash
# Inspect kernel module signing verification status
dmesg | grep -i "module signing"
# Inspect X.509 signature appended to module file
modinfo wireguard | grep signature💡Verifying Secure Boot kernel module signing status using modinfo.
🎯 Interview Key Takeaway
Kernel Module Signing enforces cryptographic X.509 signature checks to block untrusted driver code and rootkits.
#Secure Boot#Module Signing#Kernel Security#Senior
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