{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2025-39684", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-04-16T07:20:57.113Z", "datePublished": "2025-09-05T17:20:50.827Z", "dateUpdated": "2026-05-12T12:06:11.333Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-05-11T21:34:15.439Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncomedi: Fix use of uninitialized memory in do_insn_ioctl() and do_insnlist_ioctl()\n\nsyzbot reports a KMSAN kernel-infoleak in `do_insn_ioctl()`. A kernel\nbuffer is allocated to hold `insn->n` samples (each of which is an\n`unsigned int`). For some instruction types, `insn->n` samples are\ncopied back to user-space, unless an error code is being returned. The\nproblem is that not all the instruction handlers that need to return\ndata to userspace fill in the whole `insn->n` samples, so that there is\nan information leak. There is a similar syzbot report for\n`do_insnlist_ioctl()`, although it does not have a reproducer for it at\nthe time of writing.\n\nOne culprit is `insn_rw_emulate_bits()` which is used as the handler for\n`INSN_READ` or `INSN_WRITE` instructions for subdevices that do not have\na specific handler for that instruction, but do have an `INSN_BITS`\nhandler. For `INSN_READ` it only fills in at most 1 sample, so if\n`insn->n` is greater than 1, the remaining `insn->n - 1` samples copied\nto userspace will be uninitialized kernel data.\n\nAnother culprit is `vm80xx_ai_insn_read()` in the \"vm80xx\" driver. It\nnever returns an error, even if it fails to fill the buffer.\n\nFix it in `do_insn_ioctl()` and `do_insnlist_ioctl()` by making sure\nthat uninitialized parts of the allocated buffer are zeroed before\nhandling each instruction.\n\nThanks to Arnaud Lecomte for their fix to `do_insn_ioctl()`. That fix\nreplaced the call to `kmalloc_array()` with `kcalloc()`, but it is not\nalways necessary to clear the whole buffer." } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/comedi/comedi_fops.c" ], "versions": [ { "version": "ed9eccbe8970f6eedc1b978c157caf1251a896d4", "lessThan": "868a1b68dcd9f2805bb86aa64862402f785d8c4a", "status": "affected", "versionType": "git" }, { "version": "ed9eccbe8970f6eedc1b978c157caf1251a896d4", "lessThan": "ff4a7c18799c7fe999fa56c5cf276e13866b8c1a", "status": "affected", "versionType": "git" }, { "version": "ed9eccbe8970f6eedc1b978c157caf1251a896d4", "lessThan": "d84f6e77ebe3359394df32ecd97e0d76a25283dc", "status": "affected", "versionType": "git" }, { "version": "ed9eccbe8970f6eedc1b978c157caf1251a896d4", "lessThan": "f3b0c9ec54736f3b8118f93a473d22e11ee65743", "status": "affected", "versionType": "git" }, { "version": "ed9eccbe8970f6eedc1b978c157caf1251a896d4", "lessThan": "aecf0d557ddd95ce68193a5ee1dc4c87415ff08a", "status": "affected", "versionType": "git" }, { "version": "ed9eccbe8970f6eedc1b978c157caf1251a896d4", "lessThan": "3cd212e895ca2d58963fdc6422502b10dd3966bb", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/comedi/comedi_fops.c" ], "versions": [ { "version": "2.6.29", "status": "affected" }, { "version": "0", "lessThan": "2.6.29", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.190", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.149", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.103", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.44", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.16.4", "lessThanOrEqual": "6.16.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.17", "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": "2.6.29", "versionEndExcluding": "5.15.190" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.29", "versionEndExcluding": "6.1.149" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.29", "versionEndExcluding": "6.6.103" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.29", "versionEndExcluding": "6.12.44" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.29", "versionEndExcluding": "6.16.4" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.29", "versionEndExcluding": "6.17" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/868a1b68dcd9f2805bb86aa64862402f785d8c4a" }, { "url": "https://git.kernel.org/stable/c/ff4a7c18799c7fe999fa56c5cf276e13866b8c1a" }, { "url": "https://git.kernel.org/stable/c/d84f6e77ebe3359394df32ecd97e0d76a25283dc" }, { "url": "https://git.kernel.org/stable/c/f3b0c9ec54736f3b8118f93a473d22e11ee65743" }, { "url": "https://git.kernel.org/stable/c/aecf0d557ddd95ce68193a5ee1dc4c87415ff08a" }, { "url": "https://git.kernel.org/stable/c/3cd212e895ca2d58963fdc6422502b10dd3966bb" } ], "title": "comedi: Fix use of uninitialized memory in do_insn_ioctl() and do_insnlist_ioctl()", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "title": "CVE Program Container", "references": [ { "url": "https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html" } ], "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2025-11-03T17:42:16.502Z" } }, { "x_adpType": "supplier", "providerMetadata": { "orgId": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e", "shortName": "siemens-SADP", "dateUpdated": "2026-05-12T12:06:11.333Z" }, "affected": [ { "vendor": "Siemens", "product": "SIMATIC CN 4100", "versions": [ { "status": "affected", "version": "0", "lessThan": "V5.0", "versionType": "custom" } ], "defaultStatus": "unknown" } ], "references": [ { "url": "https://cert-portal.siemens.com/productcert/html/ssa-032379.html" } ] } ] } }