CVE-2026-97931
In the Linux kernel, the following vulnerability has been resolved: ALSA: us122l: Prevent write upgrades for read mappings The hwdep mmap callback rejects read-buffer mappings that are initially writable, but leaves VM_MAYWRITE set on mappings created with PROT_READ. A process that can open the hwdep node O_RDWR can later use mprotect() to make the mapping writable. The read allocation begins with struct usb_stream. Its read_size member is used by the fault handler to decide which pages belong to the read buffer. The read VMA intentionally remains expandable because pcm_usb_stream uses mremap() after reading that size. Changing read_size first can therefore map and access pages beyond the allocation. The same member is also consumed by usb_stream_free(), where changing it can make free_pages_exact() release pages outside the allocation. Clear VM_MAYWRITE for read-buffer mappings after rejecting an initially writable VMA. This keeps the separate output-buffer mapping writable while preventing later permission upgrades.
- CVSS 3.1
- 7.0
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H - EPSS
- 0.1% chance of exploitation in the next 30 days; higher than 3% of CVEs (scores of 2026-10-25)
- Published
- Modified
- Record from
- the NVD, synced
References
- https://git.kernel.org/stable/c/0eb9dd4774af0ac4d1fd105ef2b0a1f6cec06f2f
- https://git.kernel.org/stable/c/64a87950239867682cde128020e1a47088295e5c
- https://git.kernel.org/stable/c/6a5f5a5a32c78e67701f1d0f26bc87af68895604
- https://git.kernel.org/stable/c/71c610aeb1770302ac9c9e0b9a4ecd37f1311928
- https://git.kernel.org/stable/c/938e8d6cee8d36f24669dfdcd3717e081eb32d64