CVE-2026-74641

Technical Description

In the Linux kernel, the following vulnerability has been resolved:

ALSA: usx2y: bound the hwdep mmap fault offset

snd_us428ctls_vm_fault() turns the faulting page offset into a kernel

address with no bound of any kind:

offset = vmf->pgoff << PAGE_SHIFT;

vaddr = (char *)(...)->us428ctls_sharedmem + offset;

page = virt_to_page(vaddr);

get_page(page);

vmf->page = page;

return 0;

snd_us428ctls_mmap() checks only the length of the mapping, never the

offset, and us428ctls_sharedmem is a single page from

alloc_pages_exact(). For a character device file_mmap_size_max()

returns ULONG_MAX, so the mm layer imposes no ceiling either. Every page

offset above zero resolves to a struct page outside the object, and the

handler installs it into the caller's address space read-write; the vma

is not marked read-only.

The caller picks the page frame with a single mmap() argument and gets

read-write access to a page of kernel memory it does not own; an offset

that lands in an unpopulated vme

Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

References