{"id":"CVE-2026-64134","state":"PUBLISHED","title":"ALSA: pcm: Don't setup bogus iov_iter for silencing","description":"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.","publishedAt":"2026-07-19T15:40:28.974Z","updatedAt":"2026-10-19T20:28:13.823Z","severity":{"score":7.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"cf393babb37a1679a1ec1d864df1090353465e23","status":"affected","lessThan":"41a766c647294842c9b17672449f8e011048cba9","versionType":"git"},{"version":"cf393babb37a1679a1ec1d864df1090353465e23","status":"affected","lessThan":"ce836587e594af39ff048d9b29dee0f5f10692c9","versionType":"git"},{"version":"cf393babb37a1679a1ec1d864df1090353465e23","status":"affected","lessThan":"feff0251386aa6bb180a0a1cf7c1f91ba868113d","versionType":"git"},{"version":"cf393babb37a1679a1ec1d864df1090353465e23","status":"affected","lessThan":"c9f6768515818d71bdfc20119a81f3332c53b9c6","versionType":"git"},{"version":"cf393babb37a1679a1ec1d864df1090353465e23","status":"affected","lessThan":"e4d3386b74fba8e01280484b67ee481ece00201e","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["sound/core/pcm_lib.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.6","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.6","versionType":"semver"},{"version":"6.6.142","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.92","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.34","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.11","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["sound/core/pcm_lib.c"]}],"references":["https://git.kernel.org/stable/c/41a766c647294842c9b17672449f8e011048cba9","https://git.kernel.org/stable/c/ce836587e594af39ff048d9b29dee0f5f10692c9","https://git.kernel.org/stable/c/feff0251386aa6bb180a0a1cf7c1f91ba868113d","https://git.kernel.org/stable/c/c9f6768515818d71bdfc20119a81f3332c53b9c6","https://git.kernel.org/stable/c/e4d3386b74fba8e01280484b67ee481ece00201e"],"weaknesses":["CWE-476"],"ingestedAt":"2026-10-29T20:12:41.951Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/64xxx/CVE-2026-64134.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-64134","state":"PUBLISHED","datePublished":"2026-07-19T15:40:28.974Z","dateUpdated":"2026-10-19T20:28:13.823Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-07-19T07:54:57.036Z"},"containers":{"cna":{"title":"ALSA: pcm: Don't setup bogus iov_iter for silencing","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."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"cf393babb37a1679a1ec1d864df1090353465e23","status":"affected","lessThan":"41a766c647294842c9b17672449f8e011048cba9","versionType":"git"},{"version":"cf393babb37a1679a1ec1d864df1090353465e23","status":"affected","lessThan":"ce836587e594af39ff048d9b29dee0f5f10692c9","versionType":"git"},{"version":"cf393babb37a1679a1ec1d864df1090353465e23","status":"affected","lessThan":"feff0251386aa6bb180a0a1cf7c1f91ba868113d","versionType":"git"},{"version":"cf393babb37a1679a1ec1d864df1090353465e23","status":"affected","lessThan":"c9f6768515818d71bdfc20119a81f3332c53b9c6","versionType":"git"},{"version":"cf393babb37a1679a1ec1d864df1090353465e23","status":"affected","lessThan":"e4d3386b74fba8e01280484b67ee481ece00201e","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["sound/core/pcm_lib.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.6","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.6","versionType":"semver"},{"version":"6.6.142","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.92","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.34","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.11","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["sound/core/pcm_lib.c"]}],"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"}],"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."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T12:39:36.211Z"},"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"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-64134","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T15:36:56.282680Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-476","lang":"en","type":"CWE","description":"CWE-476 NULL Pointer Dereference"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T20:28:13.823Z"}}]}}}