CVE-2026-74641ALSA: usx2y: bound the hwdep mmap fault offset

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 vmemmap region oopses instead. A process that can open the hwdep node of an attached US-X2Y reaches this after loading the FPGA image through the same node; no capability check is involved. On 7.2.0-rc5 (arm64), mmap() with a large offset: Unable to handle kernel paging request at virtual address fffffdffc45d5ac8 pc : snd_us428ctls_vm_fault+0x68/0x140 [snd_usb_usx2y] Call trace: snd_us428ctls_vm_fault+0x68/0x140 [snd_usb_usx2y] __do_fault __handle_mm_fault handle_mm_fault el0_da Reject any offset outside the shared region. The pcm hwdep handler in usx2yhwdeppcm.c computes its address the same way and needs the same bound. Discovered by XBOW, triaged by Baul Lee <[email protected]>

Timeline

Scores

EPSS (exploitation in 30 days)

0.13% · top 97% of all CVEs (12 Nov 2026)

CISA SSVC

Exploitation: none · Automatable: no · Technical impact: total

The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.8.

Affected products

• Linux · Linux

  • affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 – < ad6fedea65c6e90eda00d716c8bf20cdc437ed10
  • affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 – < 10a87401fb3148c388e55df0148295b3b137da07
  • affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 – < 34ab56ed854baa73a731cfd99af689f0b1bac444
  • affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 – < 4208db2453e1ea71b8048a5b7802360cb29a53f1
  • affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 – < f613b4a2d87247b51a1b2b330f2e083a454125f2
  • affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 – < f75d6f61f0d9c5c1ea725104014e10d26d1e3a00
  • affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 – < 5bf5ccddf00b59f1e3ea7e65d76a5f5b5c21cc2e
  • affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 – < 2ca1eea3cd17930daffe9e429a7c89232036ec24

• Linux · Linux

  • affected 2.6.12
  • unaffected < 2.6.12
  • unaffected 5.10.266 – ≤ 5.10.*
  • unaffected 5.15.216 – ≤ 5.15.*
  • unaffected 6.1.183 – ≤ 6.1.*
  • unaffected 6.6.152 – ≤ 6.6.*
  • unaffected 6.12.104 – ≤ 6.12.*
  • unaffected 6.18.45 – ≤ 6.18.*
  • unaffected 7.1.9 – ≤ 7.1.*
  • unaffected 7.2 – ≤ *

Sources

The same CVE in the primary databases and aggregators, to check against.

• CVE.org record (opens in a new tab)
• CVE List JSON (GitHub) (opens in a new tab)
• NVD (opens in a new tab)
• FIRST EPSS (opens in a new tab)
• EUVD EUVD-2026-64578 (opens in a new tab)
• OSV.dev (opens in a new tab)
• GitHub Advisories (opens in a new tab)
• CIRCL Vulnerability-Lookup (opens in a new tab)

Badge for a README or a ticket

[![CVE-2026-74641](https://cveledger.app/badge/CVE-2026-74641.svg)](https://cveledger.app/cve/CVE-2026-74641)

Record last updated 16 Oct 2026, 19:06 UTC.