Bug 2424870 (CVE-2025-68376)

Summary: CVE-2025-68376 kernel: coresight: ETR: Fix ETR buffer use-after-free issue
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
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OS: Linux   
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Description OSIDB Bzimport 2025-12-24 11:02:26 UTC 
In the Linux kernel, the following vulnerability has been resolved:

coresight: ETR: Fix ETR buffer use-after-free issue

When ETR is enabled as CS_MODE_SYSFS, if the buffer size is changed
and enabled again, currently sysfs_buf will point to the newly
allocated memory(buf_new) and free the old memory(buf_old). But the
etr_buf that is being used by the ETR remains pointed to buf_old, not
updated to buf_new. In this case, it will result in a memory
use-after-free issue.

Fix this by checking ETR's mode before updating and releasing buf_old,
if the mode is CS_MODE_SYSFS, then skip updating and releasing it.
Comment 1 Alexander B 2025-12-25 16:32:51 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025122402-CVE-2025-68376-a954@gregkh/T