SB2026091756 - Integer underflow in Linux kernel loongarch kernel

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Main Vulnerability Database SB2026091756

SB2026091756 - Integer underflow in Linux kernel loongarch kernel

Published: September 17, 2026

Security Bulletin ID SB2026091756
CSH Severity
Low
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Local access
Highest impact Code execution

Breakdown by Severity

Low 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Integer underflow (CVE-ID: CVE-2026-89902)

CWE-ID: CWE-191 - Integer underflow

CVSSv4: 8.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]


The vulnerability allows a local user to bypass a BPF cgroup socket creation policy.

The vulnerability exists due to preempt count underflow in the LoongArch kprobe_singlestep_handler() function when processing an ordinary userspace breakpoint using code 11. A local user can issue a code 11 breakpoint and open a socket from a SIGTRAP handler to bypass a BPF cgroup socket creation policy.

The socket can be attributed to the root cgroup rather than the task's own cgroup.


Remediation

Install update from vendor's website.

References