Bug 2527855 (CVE-2026-80757)

Summary: CVE-2026-80757 kernel: selinux: reject a class permission count below its inherited common
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: akhatavk, aos-team-art-private, asdas, dpaolell, jdelft, jupierce, lgarciaa, mbiarnes, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, suppawar, vlaad, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel's Security-Enhanced Linux (SELinux) component. When an SELinux policy is loaded, the system fails to properly validate the number of permissions declared by a class that inherits permissions from a common set. This oversight can lead to an out-of-bounds heap write, resulting in memory corruption. An attacker could potentially exploit this to impact system stability or integrity.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
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Description OSIDB Bzimport 2026-09-03 08:42:00 UTC 
In the Linux kernel, the following vulnerability has been resolved:

selinux: reject a class permission count below its inherited common

security_get_permissions() maps an inherited common's permissions into
an array sized by the class's own permissions.nprim, but class_read()
takes that nprim verbatim from the policy image and never checks that it
covers the common.  A class that inherits a common of N permissions while
declaring a smaller nprim is accepted, and on load the common's
permissions are written past the class-sized array -- an out-of-bounds
heap write.

Reject a class whose permission count is below its inherited common's.
Well-formed policies, where the class count already includes the
inherited permissions, are unaffected.
Comment 1 Mauro Matteo Cascella 2026-09-04 13:28:02 UTC 
Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-80757.mbox