{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-97931", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-25T10:18:58.203Z", "datePublished": "2026-09-25T10:22:47.382Z", "dateUpdated": "2026-10-19T09:10:58.123Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T09:10:58.123Z" }, "descriptions": [ { "lang": "en", "value": "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 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." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The bad data is written by a local process. It maps the us122l hwdep read buffer PROT_READ via usb_stream_hwdep_mmap(), upgrades it with mprotect() because VM_MAYWRITE was never cleared, and overwrites usb_stream.read_size. No remote protocol or USB packet carries the malicious value.\nAC:H - The driver only binds, and only creates /dev/snd/hwC*D*, when a TASCAM US-122L/US-144 is attached. A local attacker can't produce that hardware without physical access. Once it is present, mmap, mprotect, a read_size overwrite and mremap are fully deterministic.\nPR:L - The attacker needs an O_RDWR open of the hwdep node, which a normal user gets through audio group or seat uaccess ACLs. usb_stream_hwdep_open() and usb_stream_hwdep_ioctl() do no capability checks, and the stream already exists from probe.\nUI:N - The attacker's own process does the open, mmap, mprotect, write to read_size, mremap and page faults. No other user has to act.\nS:U - The result is corrupted kernel memory and local privilege escalation within the same kernel authority. No VM or hardware isolation boundary is crossed.\nC:H - With an inflated read_size, usb_stream_hwdep_vm_fault() maps virt_to_page((char *)s + offset) for offsets past the alloc_pages_exact() buffer. Userspace can then directly read arbitrary adjacent kernel pages.\nI:H - Those out-of-bounds pages are mapped writable into userspace, giving direct write access to kernel memory. In addition, usb_stream_free() calls free_pages_exact(s, read_size) with the tampered size, freeing pages that are still in use, a page-level use-after-free.\nA:H - Writing to foreign kernel pages, or freeing the wrong pages through usb_stream_free() on SET_PARAMS re-init or disconnect, corrupts the page allocator and kernel data, which leads to an oops or panic." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "sound/usb/usx2y/us122l.c" ], "versions": [ { "version": "030a07e441296c372f946cd4065b5d831d8dc40c", "lessThan": "cbc1f954ce67d739d41d1f0757d29850353ebb6a", "status": "affected", "versionType": "git" }, { "version": "030a07e441296c372f946cd4065b5d831d8dc40c", "lessThan": "becb89036a1320ef0a77da2d27935ac0704345c4", "status": "affected", "versionType": "git" }, { "version": "030a07e441296c372f946cd4065b5d831d8dc40c", "lessThan": "6a5f5a5a32c78e67701f1d0f26bc87af68895604", "status": "affected", "versionType": "git" }, { "version": "030a07e441296c372f946cd4065b5d831d8dc40c", "lessThan": "938e8d6cee8d36f24669dfdcd3717e081eb32d64", "status": "affected", "versionType": "git" }, { "version": "030a07e441296c372f946cd4065b5d831d8dc40c", "lessThan": "64a87950239867682cde128020e1a47088295e5c", "status": "affected", "versionType": "git" }, { "version": "030a07e441296c372f946cd4065b5d831d8dc40c", "lessThan": "d9c537b14f4982f17b103e3a2cfeee4bee6bc026", "status": "affected", "versionType": "git" }, { "version": "030a07e441296c372f946cd4065b5d831d8dc40c", "lessThan": "0eb9dd4774af0ac4d1fd105ef2b0a1f6cec06f2f", "status": "affected", "versionType": "git" }, { "version": "030a07e441296c372f946cd4065b5d831d8dc40c", "lessThan": "71c610aeb1770302ac9c9e0b9a4ecd37f1311928", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "sound/usb/usx2y/us122l.c" ], "versions": [ { "version": "2.6.28", "status": "affected" }, { "version": "0", "lessThan": "2.6.28", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.271", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.222", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.189", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.158", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.111", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.53", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.7", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.3", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.28", "versionEndExcluding": "5.10.271" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.28", "versionEndExcluding": "5.15.222" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.28", "versionEndExcluding": "6.1.189" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.28", "versionEndExcluding": "6.6.158" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.28", "versionEndExcluding": "6.12.111" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.28", "versionEndExcluding": "6.18.53" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.28", "versionEndExcluding": "7.2.7" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.28", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/cbc1f954ce67d739d41d1f0757d29850353ebb6a" }, { "url": "https://git.kernel.org/stable/c/becb89036a1320ef0a77da2d27935ac0704345c4" }, { "url": "https://git.kernel.org/stable/c/6a5f5a5a32c78e67701f1d0f26bc87af68895604" }, { "url": "https://git.kernel.org/stable/c/938e8d6cee8d36f24669dfdcd3717e081eb32d64" }, { "url": "https://git.kernel.org/stable/c/64a87950239867682cde128020e1a47088295e5c" }, { "url": "https://git.kernel.org/stable/c/d9c537b14f4982f17b103e3a2cfeee4bee6bc026" }, { "url": "https://git.kernel.org/stable/c/0eb9dd4774af0ac4d1fd105ef2b0a1f6cec06f2f" }, { "url": "https://git.kernel.org/stable/c/71c610aeb1770302ac9c9e0b9a4ecd37f1311928" } ], "title": "ALSA: us122l: Prevent write upgrades for read mappings", "x_generator": { "engine": "bippy-1.2.0" } } } }