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Review reviewHigh

CVE-2026-64402

Linux

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...

CVSS
7.8
EPSS
-
- percentile
CISA KEV
Not listed
Published
2026.07.25
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability-
Technical severityCVSS 7.8

Vulnerability overview

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...

Affected product and versions

Product
Linux
Affected versions
>= 06f5c2926aaa0fba7f99678da6ef77cbbbda1441 < 38dbc8db8341ccdf8e1e1a067453d33ad751864b, >= 06f5c2926aaa0fba7f99678da6ef77cbbbda1441 < 4c5a0a946373da99a80398289b28845b5ae40cd1, >= 06f5c2926aaa0fba7f99678da6ef77cbbbda1441 < 661a019ac0413ecec9e5d1dfcc12fbca8e78d5fb, >= 06f5c2926aaa0fba7f99678da6ef77cbbbda1441 < daf6246ab988fc8bdc82ad7c8d0b1c182d11b15f, >= 06f5c2926aaa0fba7f99678da6ef77cbbbda1441 < 98495b5a4d77dd22e106f462b76e1093a55b29a7, >= 6.3
Fixed versions
No verified fixed-version field is available yet

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that Linux and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE
Not available