SB20260727352 - Incorrect calculation in Linux kernel x86 kernel

Description

This security bulletin contains information about 1 vulnerability.

1) Incorrect calculation (CVE-ID: CVE-2026-64235)

CWE-ID: CWE-682 - Incorrect Calculation

CVSSv4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to improper relocation of %rip-relative percpu references in dynamic ftrace trampolines in arch/x86/kernel/ftrace.c when registering a dynamic ftrace trampoline with call depth accounting enabled. A local user can register a crafted tracing configuration and trigger execution of a traced function to cause a denial of service.

Exploitation requires CONFIG_CALL_DEPTH_TRACKING on an x86 retbleed-affected platform with retbleed=stuff enabled.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/8093442a2d1d4b42b9340a86023ccb2afb30b93a
• https://git.kernel.org/stable/c/9edff632ca216169846f8a63a5a3dc467e239c7a
• https://git.kernel.org/stable/c/a17dc12bfed8868e6a86f3b45c16065a70641acb
• https://git.kernel.org/stable/c/d59cc66b702757e3c5a711e78a38583eac0c2738