Bug 2516913 (CVE-2026-74273)

Summary: CVE-2026-74273 kernel: cxl/region: Block region delete during region creation
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel's cxl/region component. A local user could exploit a race condition during the creation and deletion of regions. This could lead to the kernel becoming confused about the state of a region, potentially causing system instability or a denial of service (DoS).
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Description OSIDB Bzimport 2026-08-15 06:40:05 UTC 
In the Linux kernel, the following vulnerability has been resolved:

cxl/region: Block region delete during region creation

Expand the range lock, rename it "regions_lock", to disable region deletion
in the critical period between construct_region() and attach_target(), as
well as the period between device_add() and registering the remove actions.

Otherwise, userspace can confuse the kernel. It can violate the assumption
the region stays registered through the completion of cxl_add_to_region().
It can violate the assumption that devm_add_action_or_reset() is working
with a live 'struct cxl_region'.

It is ok for the region to disappear outside of those windows as that
mirrors device hotplug flows where the proper locks are held.
Comment 1 Keith Grant 2026-08-20 13:32:58 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026081544-CVE-2026-74273-f9f6@gregkh/T