CVE-2026-64402
coresight: ultrasoc-smb: Fix OOB write in smb_sync_perf_buffer()
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().
INFO
Published Date :
July 25, 2026, 10:17 a.m.
Last Modified :
July 25, 2026, 10:17 a.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Solution
- Normalize head modulo AUX buffer size.
- Derive page index and offset correctly.
- Index into dst_pages using the normalized value.
- Apply normalization before the first loop iteration.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-64402.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-64402 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-64402
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
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The following list is the news that have been mention
CVE-2026-64402 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-64402 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jul. 25, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '06f5c2926aaa0fba7f99678da6ef77cbbbda1441', 'lessThan': '38dbc8db8341ccdf8e1e1a067453d33ad751864b', 'versionType': 'git'}, {'status': 'affected', 'version': '06f5c2926aaa0fba7f99678da6ef77cbbbda1441', 'lessThan': '4c5a0a946373da99a80398289b28845b5ae40cd1', 'versionType': 'git'}, {'status': 'affected', 'version': '06f5c2926aaa0fba7f99678da6ef77cbbbda1441', 'lessThan': '661a019ac0413ecec9e5d1dfcc12fbca8e78d5fb', 'versionType': 'git'}, {'status': 'affected', 'version': '06f5c2926aaa0fba7f99678da6ef77cbbbda1441', 'lessThan': 'daf6246ab988fc8bdc82ad7c8d0b1c182d11b15f', 'versionType': 'git'}, {'status': 'affected', 'version': '06f5c2926aaa0fba7f99678da6ef77cbbbda1441', 'lessThan': '98495b5a4d77dd22e106f462b76e1093a55b29a7', 'versionType': 'git'}], 'programFiles': ['drivers/hwtracing/coresight/ultrasoc-smb.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '6.3'}, {'status': 'unaffected', 'version': '0', 'lessThan': '6.3', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.6.145', 'versionType': 'semver', 'lessThanOrEqual': '6.6.*'}, {'status': 'unaffected', 'version': '6.12.96', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.39', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.4', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2-rc1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['drivers/hwtracing/coresight/ultrasoc-smb.c'], 'defaultStatus': 'affected'}] Added 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(). Added Reference https://git.kernel.org/stable/c/38dbc8db8341ccdf8e1e1a067453d33ad751864b Added Reference https://git.kernel.org/stable/c/4c5a0a946373da99a80398289b28845b5ae40cd1 Added Reference https://git.kernel.org/stable/c/661a019ac0413ecec9e5d1dfcc12fbca8e78d5fb Added Reference https://git.kernel.org/stable/c/98495b5a4d77dd22e106f462b76e1093a55b29a7 Added Reference https://git.kernel.org/stable/c/daf6246ab988fc8bdc82ad7c8d0b1c182d11b15f