coresight: ultrasoc-smb: Fix OOB write in smb_sync_perf_buffer()
In the Linux kernel, the following vulnerability has been resolved: coresight: ultrasoc-smb: Fix OOB write in smb_sync_perf_buffer() When the SMB sink is used as a perf AUX sink, smb_update_buffer() calls smb_sync_perf_buffer() to copy hardware trace data into the perf AUX ring buffer pages. It derives pg_idx = head >> PAGE_SHIFT from @head, which is handle->head, and indexes dst_pages[pg_idx]. The pg_idx %= nr_pages normalization is only applied after the first loop iteration. This leaves the initial page index underived from the buffer size, which can result in an out-of-bounds write past dst_pages[] when head exceeds the AUX buffer size. Normalize head modulo the AUX buffer size before deriving the page index and offset, mirroring tmc_etr_sync_perf_buffer().
- Products
- Kernel
- Affected versions
- Not specified
- Fixed versions
- 6.12.96, 6.18.39, 6.6.145, 7.1.4
- CVEs
- CVE-2026-64402
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 3 Nov 2026, 19:32 UTC · Revision 1
Source evidence
coresight: ultrasoc-smb: Fix OOB write in smb_sync_perf_buffer()
core-osv · Original sourcePublished 25 Jul 2026, 08:50 UTC
In the Linux kernel, the following vulnerability has been resolved: coresight: ultrasoc-smb: Fix OOB write in smb_sync_perf_buffer() When the SMB sink is used as a perf AUX sink, smb_update_buffer() calls smb_sync_perf_buffer() to copy hardware trace data into the perf AUX ring buffer pages. It derives pg_idx = head >> PAGE_SHIFT from @head, which is handle->head, and indexes dst_pages[pg_idx]. The pg_idx %= nr_pages normalization is only applied after the first loop iteration. This leaves the initial page index underived from the buffer size, which can result in an out-of-bounds write past dst_pages[] when head exceeds the AUX buffer size. Normalize head modulo the AUX buffer size before deriving the page index and offset, mirroring tmc_etr_sync_perf_buffer().
osv:CVE-2026-64402
Kernel
Fixed versions: 6.6.145, 6.12.96, 6.18.39, 7.1.4
Complete source record
{
"id": "1f4eae91d60e58b48e4083f35228355b96936fdb93392674fadbe01cf8b07af5",
"url": "https://osv.dev/vulnerability/CVE-2026-64402",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "coresight: ultrasoc-smb: Fix OOB write in smb_sync_perf_buffer()",
"summary": "In the Linux kernel, the following vulnerability has been resolved: coresight: ultrasoc-smb: Fix OOB write in smb_sync_perf_buffer() When the SMB sink is used as a perf AUX sink, smb_update_buffer() calls smb_sync_perf_buffer() to copy hardware trace data into the perf AUX ring buffer pages. It derives pg_idx = head >> PAGE_SHIFT from @head, which is handle->head, and indexes dst_pages[pg_idx]. The pg_idx %= nr_pages normalization is only applied after the first loop iteration. This leaves the initial page index underived from the buffer size, which can result in an out-of-bounds write past dst_pages[] when head exceeds the AUX buffer size. Normalize head modulo the AUX buffer size before deriving the page index and offset, mirroring tmc_etr_sync_perf_buffer().",
"evidence": "osv:CVE-2026-64402",
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"severity": "high",
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"metrics": [
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"package": {
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"database_specific": {
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],
"modified": "2026-10-28T02:30:31.688895196Z",
"provider": "osv",
"references": [
"https://git.kernel.org/stable/c/38dbc8db8341ccdf8e1e1a067453d33ad751864b",
"https://git.kernel.org/stable/c/4c5a0a946373da99a80398289b28845b5ae40cd1",
"https://git.kernel.org/stable/c/661a019ac0413ecec9e5d1dfcc12fbca8e78d5fb",
"https://git.kernel.org/stable/c/98495b5a4d77dd22e106f462b76e1093a55b29a7",
"https://git.kernel.org/stable/c/daf6246ab988fc8bdc82ad7c8d0b1c182d11b15f",
"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64402.json",
"https://nvd.nist.gov/vuln/detail/CVE-2026-64402",
"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
],
"provider_metadata": {
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"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64402.json"
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"related_cves": [
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"evidence": "/id"
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"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 498742,
"published_at": "2026-07-25T08:50:45.075+00:00"
}