{"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"}}}}