PT-2026-64623 · Linux · Linux

CVE-2026-64402 · Published 2026-07-25 · Updated 2026-07-25

Mitre

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().

Related Identifiers

CVE-2026-64402

Affected Products

Linux

References · 6

• https://nvd.nist.gov/vuln/detail/CVE-2026-64402 · Security Note
• https://git.kernel.org/stable/c/4c5a0a946373da99a80398289b28845b5ae40cd1 · Note
• https://git.kernel.org/stable/c/38dbc8db8341ccdf8e1e1a067453d33ad751864b · Note
• https://git.kernel.org/stable/c/daf6246ab988fc8bdc82ad7c8d0b1c182d11b15f · Note
• https://git.kernel.org/stable/c/661a019ac0413ecec9e5d1dfcc12fbca8e78d5fb · Note
• https://git.kernel.org/stable/c/98495b5a4d77dd22e106f462b76e1093a55b29a7 · Note