Missing Authorization in Linux kernel - CVE-2026-98361

Vulnerability details

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.

Affected software

How to mitigate CVE-2026-98361

External References

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

Related Security Bulletins

• Missing Authorization in Linux kernel sw rxe driver
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux, linux-aws, linux-gcp and more