CVE-2023-53491: start_kernel: Add __no_stack_protector function attribute

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-10-01 · updated 2026-10-15

Description

In the Linux kernel, the following vulnerability has been resolved: start_kernel: Add __no_stack_protector function attribute Back during the discussion of commit a9a3ed1eff36 ("x86: Fix early boot crash on gcc-10, third try") we discussed the need for a function attribute to control the omission of stack protectors on a per-function basis; at the time Clang had support for no_stack_protector but GCC did not. This was fixed in gcc-11. Now that the function attribute is available, let's start using it. Callers of boot_init_stack_canary need to use this function attribute unless they're compiled with -fno-stack-protector, otherwise the canary stored in the stack slot of the caller will differ upon the call to boot_init_stack_canary. This will lead to a call to __stack_chk_fail() then panic.

Affected products

Linux kernel: from 2.6.30 before 6.4.4 — fixed in 6.4.4

How to fix

Upgrade to a fixed version: Linux kernel 6.4.4. Check the vendor advisory for mitigations.

References

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