{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-99063", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-25T10:25:14.388Z", "datePublished": "2026-10-23T12:23:04.655Z", "dateUpdated": "2026-10-23T12:23:04.655Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-23T12:23:04.655Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndm ioctl: don't let data_start run past the buffer\n\nstruct dm_ioctl has seven bytes of trailing padding, so the smallest\nbuffer userspace is allowed to ask for, offsetof(struct dm_ioctl, data),\nis seven bytes shorter than sizeof(struct dm_ioctl).\n\nget_result_buffer() sets data_start to sizeof(struct dm_ioctl) without\nlooking at how big the buffer actually is. Ask for the minimum and\ndata_start ends up seven bytes past the end. Callers add it to\ndata_size, and ctl_ioctl() copies that much back to userspace:\n\n BUG: KASAN: slab-out-of-bounds in _copy_to_user+0xad/0xd0\n Read of size 312 at addr ffff8880169e4c00 by task repro-dm/140\n ctl_ioctl+0x5e3/0xcb0\n dm_ctl_ioctl+0x25/0x40\n allocated 305-byte region [ffff8880169e4c00, ffff8880169e4d31)\n\nA DM_LIST_DEVICES with data_size set to 305 is enough to hit it, and the\nseven bytes that leak are whatever sat next to the allocation.\n\nClamp data_start to the buffer size.\n\nNote that this is not a security bug because the out-of-bounds read can\nonly be triggered by root."}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["drivers/md/dm-ioctl.c"], "versions": [{"version": "76c072b48e39e9291fbf02d6c912cf27d65e093d", "lessThan": "98195e822343a656b92e235847ab3e72b1a3f920", "status": "affected", "versionType": "git"}, {"version": "76c072b48e39e9291fbf02d6c912cf27d65e093d", "lessThan": "e5c3f3d8935ecc64c962fb66e6a86dbf79218f61", "status": "affected", "versionType": "git"}, {"version": "76c072b48e39e9291fbf02d6c912cf27d65e093d", "lessThan": "5680b6fb3054677d4ee65d3baba24b649f1b430e", "status": "affected", "versionType": "git"}, {"version": "76c072b48e39e9291fbf02d6c912cf27d65e093d", "lessThan": "725b49c689bbb29ef740b0d6b5ea9390baa9a695", "status": "affected", "versionType": "git"}, {"version": "76c072b48e39e9291fbf02d6c912cf27d65e093d", "lessThan": "9b3fcf519d370df94a56f3b272d9eddffffa5be8", "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/md/dm-ioctl.c"], "versions": [{"version": "2.6.25", "status": "affected"}, {"version": "0", "lessThan": "2.6.25", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.160", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.113", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.57", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.2.11", "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": "2.6.25", "versionEndExcluding": "6.6.160"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.25", "versionEndExcluding": "6.12.113"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.25", "versionEndExcluding": "6.18.57"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.25", "versionEndExcluding": "7.2.11"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.25", "versionEndExcluding": "7.3"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/98195e822343a656b92e235847ab3e72b1a3f920"}, {"url": "https://git.kernel.org/stable/c/e5c3f3d8935ecc64c962fb66e6a86dbf79218f61"}, {"url": "https://git.kernel.org/stable/c/5680b6fb3054677d4ee65d3baba24b649f1b430e"}, {"url": "https://git.kernel.org/stable/c/725b49c689bbb29ef740b0d6b5ea9390baa9a695"}, {"url": "https://git.kernel.org/stable/c/9b3fcf519d370df94a56f3b272d9eddffffa5be8"}], "title": "dm ioctl: don't let data_start run past the buffer", "x_generator": {"engine": "bippy-1.2.0"}}}}

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{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["drivers/md/dm-ioctl.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "98195e822343a656b92e235847ab3e72b1a3f920", "status": "affected", "version": "76c072b48e39e9291fbf02d6c912cf27d65e093d", "versionType": "git"}, {"lessThan": "e5c3f3d8935ecc64c962fb66e6a86dbf79218f61", "status": "affected", "version": "76c072b48e39e9291fbf02d6c912cf27d65e093d", "versionType": "git"}, {"lessThan": "5680b6fb3054677d4ee65d3baba24b649f1b430e", "status": "affected", "version": "76c072b48e39e9291fbf02d6c912cf27d65e093d", "versionType": "git"}, {"lessThan": "725b49c689bbb29ef740b0d6b5ea9390baa9a695", "status": "affected", "version": "76c072b48e39e9291fbf02d6c912cf27d65e093d", "versionType": "git"}, {"lessThan": "9b3fcf519d370df94a56f3b272d9eddffffa5be8", "status": "affected", "version": "76c072b48e39e9291fbf02d6c912cf27d65e093d", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["drivers/md/dm-ioctl.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "2.6.25"}, {"lessThan": "2.6.25", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.160", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.113", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.57", "versionType": "semver"}, {"lessThanOrEqual": "7.2.*", "status": "unaffected", "version": "7.2.11", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.3", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndm ioctl: don't let data_start run past the buffer\n\nstruct dm_ioctl has seven bytes of trailing padding, so the smallest\nbuffer userspace is allowed to ask for, offsetof(struct dm_ioctl, data),\nis seven bytes shorter than sizeof(struct dm_ioctl).\n\nget_result_buffer() sets data_start to sizeof(struct dm_ioctl) without\nlooking at how big the buffer actually is. Ask for the minimum and\ndata_start ends up seven bytes past the end. Callers add it to\ndata_size, and ctl_ioctl() copies that much back to userspace:\n\n BUG: KASAN: slab-out-of-bounds in _copy_to_user+0xad/0xd0\n Read of size 312 at addr ffff8880169e4c00 by task repro-dm/140\n ctl_ioctl+0x5e3/0xcb0\n dm_ctl_ioctl+0x25/0x40\n allocated 305-byte region [ffff8880169e4c00, ffff8880169e4d31)\n\nA DM_LIST_DEVICES with data_size set to 305 is enough to hit it, and the\nseven bytes that leak are whatever sat next to the allocation.\n\nClamp data_start to the buffer size.\n\nNote that this is not a security bug because the out-of-bounds read can\nonly be triggered by root."}], "id": "CVE-2026-99063", "lastModified": "2026-10-23T13:17:30.140", "metrics": {}, "published": "2026-10-23T13:17:30.140", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/5680b6fb3054677d4ee65d3baba24b649f1b430e"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/725b49c689bbb29ef740b0d6b5ea9390baa9a695"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/98195e822343a656b92e235847ab3e72b1a3f920"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/9b3fcf519d370df94a56f3b272d9eddffffa5be8"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/e5c3f3d8935ecc64c962fb66e6a86dbf79218f61"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: dm ioctl: don't let data_start run past the buffer", "id": "2559788", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2559788"}, "csaw": false, "cvss3": {"cvss3_base_score": "2.3", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:L/I:N/A:N", "status": "draft"}, "cwe": "CWE-125", "details": ["In the Linux kernel, the following vulnerability has been resolved:\ndm ioctl: don't let data_start run past the buffer\nstruct dm_ioctl has seven bytes of trailing padding, so the smallest\nbuffer userspace is allowed to ask for, offsetof(struct dm_ioctl, data),\nis seven bytes shorter than sizeof(struct dm_ioctl).\nget_result_buffer() sets data_start to sizeof(struct dm_ioctl) without\nlooking at how big the buffer actually is. Ask for the minimum and\ndata_start ends up seven bytes past the end. Callers add it to\ndata_size, and ctl_ioctl() copies that much back to userspace:\nBUG: KASAN: slab-out-of-bounds in _copy_to_user+0xad/0xd0\nRead of size 312 at addr ffff8880169e4c00 by task repro-dm/140\nctl_ioctl+0x5e3/0xcb0\ndm_ctl_ioctl+0x25/0x40\nallocated 305-byte region [ffff8880169e4c00, ffff8880169e4d31)\nA DM_LIST_DEVICES with data_size set to 305 is enough to hit it, and the\nseven bytes that leak are whatever sat next to the allocation.\nClamp data_start to the buffer size.\nNote that this is not a security bug because the out-of-bounds read can\nonly be triggered by root.", "A flaw was found in the Linux kernel's Device Mapper (DM) subsystem. When processing certain input/output control (ioctl) requests with minimal buffer sizes, the interface fails to properly validate that the result buffer's start offset remains within the allocated memory boundaries. A local attacker with administrative privileges can exploit this flaw to cause an out-of-bounds read, leading to the disclosure of sensitive adjacent kernel memory or a system crash resulting in a Denial of Service (DoS)."], "name": "CVE-2026-99063", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Out of support scope", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Fix deferred", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Fix deferred", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/a:redhat:openshift:4", "fix_state": "Fix deferred", "package_name": "openshift/ose-rhel-coreos-8", "product_name": "Red Hat OpenShift Container Platform 4"}, {"cpe": "cpe:/a:redhat:openshift:4", "fix_state": "Fix deferred", "package_name": "openshift/ose-rhel-coreos-9", "product_name": "Red Hat OpenShift Container Platform 4"}], "public_date": "2026-10-23T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-99063\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-99063\nhttps://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-99063.mbox"], "threat_severity": "Low"}