{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-64134", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T07:54:57.036Z", "datePublished": "2026-07-19T15:40:28.974Z", "dateUpdated": "2026-08-05T12:39:36.211Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:39:36.211Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nALSA: pcm: Don't setup bogus iov_iter for silencing\n\nAt transition to the iov_iter for PCM data transfer, we blindly\napplied the iov_iter setup also for silencing (i.e. data = NULL), and\nit leads to a calculation of bogus iov_iter. Fortunately this didn't\ncause troubles on most of architectures but it goes wrong on RISC-V\nnow, causing a NULL dereference.\n\nHandle the NULL data case to treat the silencing in interleaved_copy()\nfor addressing the bug above. noninterleaved_copy() has already the\nNULL data handling, so it doesn't need changes." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The vulnerable code is reached only via local ALSA PCM interfaces—opening `/dev/snd/pcmC*D*p`, `write()`/`ioctl()` on that device, or OSS PCM emulation—not via any network-facing kernel protocol.\nAC:L - An attacker with PCM device access can reliably trigger silencing by setting `silence_size > 0` via `SNDRV_PCM_IOCTL_SW_PARAMS`, using OSS playback (which auto-enables silence), calling `snd_pcm_lib_write()` with a NULL buffer, or starting playback so `snd_pcm_playback_silence()` runs on interleaved streams.\nPR:L - Exploitation requires a local process able to open and configure a PCM playback stream (typically any logged-in desktop/mobile user with audio device access via the `audio` group, seat ACL, or equivalent permissions), not root or special capabilities.\nUI:N - Triggering the bug requires only programmatic PCM playback/silencing operations; no victim interaction such as mounting a filesystem or opening a malicious file is needed.\nS:U - Impact is confined to kernel memory safety within the ALSA PCM subsystem on the local host; it does not cross a security boundary such as VM escape, sandbox escape, or IOMMU bypass.\nC:H - Passing `data=NULL` through `do_transfer()` constructs a bogus `iov_iter` with a NULL base pointer; this is a kernel memory-safety defect in the iterator layer that can cause out-of-bounds or NULL-based reads when iterator helpers dereference the malformed state, not merely a benign error return.\nI:H - The same bogus `iov_iter` setup supplies invalid source/destination metadata to the kernel copy path; if iterator operations proceed on the malformed structure, uncontrolled kernel writes are possible, and the identical NULL-handling gap in `noninterleaved_copy()` confirms this silencing path was always meant to bypass `do_transfer()`.\nA:H - On RISC-V the defect manifests as a kernel NULL pointer dereference during silencing, causing an oops/panic and denial of service; the bug is also reachable on every architecture where interleaved PCM silencing is used." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "sound/core/pcm_lib.c" ], "versions": [ { "version": "cf393babb37a1679a1ec1d864df1090353465e23", "lessThan": "41a766c647294842c9b17672449f8e011048cba9", "status": "affected", "versionType": "git" }, { "version": "cf393babb37a1679a1ec1d864df1090353465e23", "lessThan": "ce836587e594af39ff048d9b29dee0f5f10692c9", "status": "affected", "versionType": "git" }, { "version": "cf393babb37a1679a1ec1d864df1090353465e23", "lessThan": "feff0251386aa6bb180a0a1cf7c1f91ba868113d", "status": "affected", "versionType": "git" }, { "version": "cf393babb37a1679a1ec1d864df1090353465e23", "lessThan": "c9f6768515818d71bdfc20119a81f3332c53b9c6", "status": "affected", "versionType": "git" }, { "version": "cf393babb37a1679a1ec1d864df1090353465e23", "lessThan": "e4d3386b74fba8e01280484b67ee481ece00201e", "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/core/pcm_lib.c" ], "versions": [ { "version": "6.6", "status": "affected" }, { "version": "0", "lessThan": "6.6", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.142", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.92", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.34", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.0.11", "lessThanOrEqual": "7.0.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1", "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": "6.6", "versionEndExcluding": "6.6.142" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.6", "versionEndExcluding": "6.12.92" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.6", "versionEndExcluding": "6.18.34" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.6", "versionEndExcluding": "7.0.11" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.6", "versionEndExcluding": "7.1" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/41a766c647294842c9b17672449f8e011048cba9" }, { "url": "https://git.kernel.org/stable/c/ce836587e594af39ff048d9b29dee0f5f10692c9" }, { "url": "https://git.kernel.org/stable/c/feff0251386aa6bb180a0a1cf7c1f91ba868113d" }, { "url": "https://git.kernel.org/stable/c/c9f6768515818d71bdfc20119a81f3332c53b9c6" }, { "url": "https://git.kernel.org/stable/c/e4d3386b74fba8e01280484b67ee481ece00201e" } ], "title": "ALSA: pcm: Don't setup bogus iov_iter for silencing", "x_generator": { "engine": "bippy-1.2.0" } } } }