Bug 2516751 (CVE-2026-74272)

Summary: CVE-2026-74272 kernel: cxl/region: Resolve region deletion races
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 module. Multiple race conditions exist during the deletion of CXL (Compute Express Link) regions. A local attacker could exploit these race conditions by repeatedly attempting to delete a region via the sysfs interface or by racing with kernel operations. This could lead to a denial of service (DoS) by preventing proper resource cleanup and potentially causing system instability.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-08-15 06:31:38 UTC 
In the Linux kernel, the following vulnerability has been resolved:

cxl/region: Resolve region deletion races

Sungwoo noticed that the sysfs trigger to delete a region may try to delete
a region multiple times. It also has no exclusion relative to the kernel
releasing the region via CXL root device teardown.

Instead of installing new cxl root devres actions per region, use the
existing root decoder unregistration event to remove all remaining regions.
An xarray of regions replaces a devres list of regions.

This handles 3 separate issues with the old approach:

1/ sysfs users racing to delete the same region: no longer possible now
   that the regions_lock is held over the lookup and deletion.

2/ multiple actions triggering deletion of the same region: solved by
   erasing regions while holding @regions_lock, and only proceeding on
   successful erasure.

3/ userspace racing devres_release_all() to trigger the devres not found
   warning: solved by sysfs unregistration not requiring a release action
Comment 1 Keith Grant 2026-08-20 13:27:34 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026081544-CVE-2026-74272-eb1a@gregkh/T