Vulnerability Description
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().
CVSS Score
HIGH
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
FAQ
What is CVE-2026-64402?
CVE-2026-64402 is a vulnerability with a CVSS score of 7.8 (HIGH). 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()...
How severe is CVE-2026-64402?
CVE-2026-64402 has been rated HIGH with a CVSS base score of 7.8/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-64402?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.