Medium [CVE-2026-68474] fix out-of-bounds access in spufs_mem_mmap_access

In the Linux kernel, the following vulnerability has been resolved: powerpc/spufs: fix out-of-bounds access in spufs_mem_mmap_access() spufs_mem_mmap_access() computes the local store offset as address - vma->vm_start, but bounds-checks it against vma->vm_end instead of the local store size.

On 64-bit, offset is always well below vma->vm_end, so the clamp never fires and len stays unbounded against the LS_SIZE buffer returned by ctx->ops->get_ls(). Reject offsets at or beyond LS_SIZE and clamp len to the remaining space, mirroring the guard already used by spufs_mem_mmap_fault() and spufs_ps_fault().

A flaw was found in the Linux kernel, specifically within the powerpc/spufs component responsible for managing memory access. This vulnerability allows for an out-of-bounds memory access due to incorrect boundary checks in the `spufs_mem_mmap_access()` function.

An attacker could exploit this to corrupt memory, potentially leading to system instability (denial of service) or unauthorized privilege escalation. Red Hat severity: Moderate — CVSS 5.5 (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H).

Weakness: CWE-787. Red Hat lists Red Hat Enterprise Linux 10; Red Hat Enterprise Linux 6; Red Hat Enterprise Linux 7; Red Hat Enterprise Linux 8; Red Hat Enterprise Linux 9 as not affected.