{"id":"CVE-2026-97931","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nALSA: us122l: Prevent write upgrades for read mappings\n\nThe hwdep mmap callback rejects read-buffer mappings that are initially\nwritable, but leaves VM_MAYWRITE set on …","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nALSA: us122l: Prevent write upgrades for read mappings\n\nThe hwdep mmap callback rejects read-buffer mappings that are initially\nwritable, but leaves VM_MAYWRITE set on …","severity":"high","vendor":"Linux","product":"Linux","affected":["Linux >= 030a07e441296c372f946cd4065b5d831d8dc40c < 64a87950239867682cde128020e1a47088295e5c","Linux >= 030a07e441296c372f946cd4065b5d831d8dc40c < d9c537b14f4982f17b103e3a2cfeee4bee6bc026","Linux >= 030a07e441296c372f946cd4065b5d831d8dc40c < 0eb9dd4774af0ac4d1fd105ef2b0a1f6cec06f2f","Linux >= 030a07e441296c372f946cd4065b5d831d8dc40c < 71c610aeb1770302ac9c9e0b9a4ecd37f1311928","Linux 2.6.28"],"published":"2026-09-25","updated":"2026-09-25","sourceUpdated":"2026-09-25T11:17:20.387","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-97931","references":[{"url":"https://git.kernel.org/stable/c/0eb9dd4774af0ac4d1fd105ef2b0a1f6cec06f2f","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/64a87950239867682cde128020e1a47088295e5c","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/71c610aeb1770302ac9c9e0b9a4ecd37f1311928","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/d9c537b14f4982f17b103e3a2cfeee4bee6bc026","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd","cve.org"],"ingestedAt":"2026-09-25T11:06:38.885Z","cvss":7,"cvssVector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","slug":"CVE-2026-97931","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nALSA: us122l: Prevent write upgrades for read mappings\n\nThe hwdep mmap callback rejects read-buffer mappings that are initially\nwritable, but leaves VM_MAYWRITE set on mappings created with PROT_READ.\nA process that can open the hwdep node O_RDWR can later use mprotect() to\nmake the mapping writable.\n\nThe read allocation begins with struct usb_stream. Its read_size member is\nused by the fault handler to decide which pages belong to the read buffer.\nThe read VMA intentionally remains expandable because pcm_usb_stream uses\nmremap() after reading that size. Changing read_size first can therefore\nmap and access pages beyond the allocation. The same member is also\nconsumed by usb_stream_free(), where changing it can make\nfree_pages_exact() release pages outside the allocation.\n\nClear VM_MAYWRITE for read-buffer mappings after rejecting an initially\nwritable VMA. This keeps the separate output-buffer mapping writable while\npreventing later permission upgrades.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":39,"depthScoreParts":{"impact":38.5,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":210952,"id":"CVE-2026-97931","ts":1790349118466,"field":"cvss","old":null,"new":"7"},{"seq":210951,"id":"CVE-2026-97931","ts":1790349118466,"field":"severity","old":"none","new":"high"}]}