SB2026100714 - Missing Authorization in Linux kernel sw rxe driver

Description

This security bulletin contains information about 1 vulnerability.

1) Missing Authorization (CVE-ID: CVE-2026-98361)

CWE-ID: CWE-862 - Missing Authorization

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

The vulnerability allows a local user to modify files opened with read-only access.

The vulnerability exists due to missing write-permission validation in rxe_check_pagefault() in the RDMA/rxe on-demand paging implementation when processing write operations against read-only file-backed mappings. A local user can register an on-demand paging memory region over such a mapping and use incoming RDMA traffic to modify files opened with read-only access.

The writes modify page-cache data without breaking copy-on-write. Affected operations include RDMA WRITE, RDMA READ responses, SEND payloads, and atomic operations. Potential targets include /etc/passwd and setuid binaries.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/2d6c6f94d3e1cde049fe5db71dbd5549f10b2de1
• https://git.kernel.org/stable/c/769001ce838d907ecaa95f1d0a4e8fc86f761f9f
• https://git.kernel.org/stable/c/c6f56982ec5c7da83c4bdfcce3b6db18bcfe6425