CVE-2026-64402

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-64402", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T15:36:31.785Z", "datePublished": "2026-07-25T08:50:45.075Z", "dateUpdated": "2026-08-17T04:55:00.113Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T04:55:00.113Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncoresight: ultrasoc-smb: Fix OOB write in smb_sync_perf_buffer()\n\nWhen the SMB sink is used as a perf AUX sink, smb_update_buffer() calls\nsmb_sync_perf_buffer() to copy hardware trace data into the perf AUX ring\nbuffer pages. It derives pg_idx = head >> PAGE_SHIFT from @head, which is\nhandle->head, and indexes dst_pages[pg_idx]. The pg_idx %= nr_pages\nnormalization is only applied after the first loop iteration.\n\nThis leaves the initial page index underived from the buffer size, which\ncan result in an out-of-bounds write past dst_pages[] when head exceeds\nthe AUX buffer size.\n\nNormalize head modulo the AUX buffer size before deriving the page index\nand offset, mirroring tmc_etr_sync_perf_buffer()."}], "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 path is reached locally through perf_event_open(), AUX-buffer mmap, and perf event scheduling or ioctls; it has no network or physical entry point.\nAC:L - An attacker can choose a small AUX buffer, advance aux_tail, and repeatedly stop and restart their own trace until the monotonically increasing head crosses the buffer size. No race or condition outside the attacker's control is required.\nPR:L - A self-targeted event with exclude_kernel=1 is available to an ordinary unprivileged user under the mainline default perf_event_paranoid setting, and selecting the SMB sink requires no privileged sysfs write.\nUI:N - The attacker creates, runs, consumes, and stops their own tracing event without any victim action.\nS:U - Exploitation compromises the host kernel within the same security authority and does not inherently cross a VM, IOMMU, or other separate security boundary.\nC:H - The out-of-range page-pointer lookup directs memcpy() through a pointer obtained from groomable adjacent kernel memory. Resulting kernel-memory corruption can plausibly enable control-flow hijacking and unrestricted disclosure.\nI:H - The attacker-influenced trace data is written through an invalid kernel pointer, providing exploitable memory corruption that can plausibly yield arbitrary kernel modification or code execution.\nA:H - An ungroomed invalid destination pointer can immediately cause a kernel oops or panic, and the attacker can trigger the path repeatedly."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["drivers/hwtracing/coresight/ultrasoc-smb.c"], "versions": [{"version": "06f5c2926aaa0fba7f99678da6ef77cbbbda1441", "lessThan": "38dbc8db8341ccdf8e1e1a067453d33ad751864b", "status": "affected", "versionType": "git"}, {"version": "06f5c2926aaa0fba7f99678da6ef77cbbbda1441", "lessThan": "4c5a0a946373da99a80398289b28845b5ae40cd1", "status": "affected", "versionType": "git"}, {"version": "06f5c2926aaa0fba7f99678da6ef77cbbbda1441", "lessThan": "661a019ac0413ecec9e5d1dfcc12fbca8e78d5fb", "status": "affected", "versionType": "git"}, {"version": "06f5c2926aaa0fba7f99678da6ef77cbbbda1441", "lessThan": "daf6246ab988fc8bdc82ad7c8d0b1c182d11b15f", "status": "affected", "versionType": "git"}, {"version": "06f5c2926aaa0fba7f99678da6ef77cbbbda1441", "lessThan": "98495b5a4d77dd22e106f462b76e1093a55b29a7", "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/hwtracing/coresight/ultrasoc-smb.c"], "versions": [{"version": "6.3", "status": "affected"}, {"version": "0", "lessThan": "6.3", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.145", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.96", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.39", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.1.4", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.2", "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": "6.3", "versionEndExcluding": "6.6.145"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.3", "versionEndExcluding": "6.12.96"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.3", "versionEndExcluding": "6.18.39"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.3", "versionEndExcluding": "7.1.4"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.3", "versionEndExcluding": "7.2"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/38dbc8db8341ccdf8e1e1a067453d33ad751864b"}, {"url": "https://git.kernel.org/stable/c/4c5a0a946373da99a80398289b28845b5ae40cd1"}, {"url": "https://git.kernel.org/stable/c/661a019ac0413ecec9e5d1dfcc12fbca8e78d5fb"}, {"url": "https://git.kernel.org/stable/c/daf6246ab988fc8bdc82ad7c8d0b1c182d11b15f"}, {"url": "https://git.kernel.org/stable/c/98495b5a4d77dd22e106f462b76e1093a55b29a7"}], "title": "coresight: ultrasoc-smb: Fix OOB write in smb_sync_perf_buffer()", "x_generator": {"engine": "bippy-1.2.0"}}}}

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{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["drivers/hwtracing/coresight/ultrasoc-smb.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "38dbc8db8341ccdf8e1e1a067453d33ad751864b", "status": "affected", "version": "06f5c2926aaa0fba7f99678da6ef77cbbbda1441", "versionType": "git"}, {"lessThan": "4c5a0a946373da99a80398289b28845b5ae40cd1", "status": "affected", "version": "06f5c2926aaa0fba7f99678da6ef77cbbbda1441", "versionType": "git"}, {"lessThan": "661a019ac0413ecec9e5d1dfcc12fbca8e78d5fb", "status": "affected", "version": "06f5c2926aaa0fba7f99678da6ef77cbbbda1441", "versionType": "git"}, {"lessThan": "daf6246ab988fc8bdc82ad7c8d0b1c182d11b15f", "status": "affected", "version": "06f5c2926aaa0fba7f99678da6ef77cbbbda1441", "versionType": "git"}, {"lessThan": "98495b5a4d77dd22e106f462b76e1093a55b29a7", "status": "affected", "version": "06f5c2926aaa0fba7f99678da6ef77cbbbda1441", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["drivers/hwtracing/coresight/ultrasoc-smb.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "6.3"}, {"lessThan": "6.3", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.145", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.96", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.39", "versionType": "semver"}, {"lessThanOrEqual": "7.1.*", "status": "unaffected", "version": "7.1.4", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.2", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "FFC8CB6D-729C-42F2-8BDB-05E9ACC289A4", "versionEndExcluding": "6.6.145", "versionStartIncluding": "6.3", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "38A8100E-2B1A-462F-AEE9-8901B870FEF2", "versionEndExcluding": "6.12.96", "versionStartIncluding": "6.7", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "914AE4BC-3D59-4C5A-9DB5-9CE327B429F7", "versionEndExcluding": "6.18.39", "versionStartIncluding": "6.13", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "6228DDD6-4557-4AA3-9F43-AB995D471E42", "versionEndExcluding": "7.1.4", "versionStartIncluding": "6.19", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncoresight: ultrasoc-smb: Fix OOB write in smb_sync_perf_buffer()\n\nWhen the SMB sink is used as a perf AUX sink, smb_update_buffer() calls\nsmb_sync_perf_buffer() to copy hardware trace data into the perf AUX ring\nbuffer pages. It derives pg_idx = head >> PAGE_SHIFT from @head, which is\nhandle->head, and indexes dst_pages[pg_idx]. The pg_idx %= nr_pages\nnormalization is only applied after the first loop iteration.\n\nThis leaves the initial page index underived from the buffer size, which\ncan result in an out-of-bounds write past dst_pages[] when head exceeds\nthe AUX buffer size.\n\nNormalize head modulo the AUX buffer size before deriving the page index\nand offset, mirroring tmc_etr_sync_perf_buffer()."}], "id": "CVE-2026-64402", "lastModified": "2026-09-04T14:45:56.780", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 7.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 5.9, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}]}, "published": "2026-07-25T10:17:23.737", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/38dbc8db8341ccdf8e1e1a067453d33ad751864b"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/4c5a0a946373da99a80398289b28845b5ae40cd1"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/661a019ac0413ecec9e5d1dfcc12fbca8e78d5fb"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/98495b5a4d77dd22e106f462b76e1093a55b29a7"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/daf6246ab988fc8bdc82ad7c8d0b1c182d11b15f"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-787"}], "source": "nvd@nist.gov", "type": "Primary"}]}

{"bugzilla": {"description": "kernel: coresight: ultrasoc-smb: Fix OOB write in smb_sync_perf_buffer()", "id": "2507214", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2507214"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.0", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H", "status": "draft"}, "cwe": "CWE-787", "details": ["A flaw was found in the Linux kernel's coresight ultrasoc-smb component. This vulnerability involves an out-of-bounds write in the `smb_sync_perf_buffer()` function. An attacker could potentially exploit this by causing the system to write data beyond the intended memory buffer, which may lead to system instability or a denial of service (DoS). This occurs because a page index is calculated incorrectly before being properly normalized, allowing the system to access memory outside its allocated boundaries."], "name": "CVE-2026-64402", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-07-25T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-64402\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-64402\nhttps://lore.kernel.org/linux-cve-announce/2026072530-CVE-2026-64402-af30@gregkh/T"], "threat_severity": "Moderate"}

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