{ "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" } } } }