SB2026091873 - Incorrect Conversion between Numeric Types in Linux kernel s390 net

Description

This security bulletin contains information about 1 vulnerability.

1) Incorrect Conversion between Numeric Types (CVE-ID: CVE-2026-93147)

CWE-ID: CWE-681 - Incorrect Conversion between Numeric Types

CVSSv4: 0 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:N/SC:N/SI:N/SA:N]

The vulnerability allows a local user to cause BPF_REG_0 to contain a cpu_nr value with uncleared upper bits.

The vulnerability exists due to improper zero extension in the s390 BPF JIT compiler when compiling BPF instructions that invoke BPF_FUNC_get_smp_processor_id. A local user can execute a BPF program that invokes BPF_FUNC_get_smp_processor_id to cause BPF_REG_0 to contain a cpu_nr value with uncleared upper bits.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/5f6cc299938b561cb01e343bab7042611fcee12a
• https://git.kernel.org/stable/c/88500a86ab79f01c568de6ed00f5b1c5c79f11d5