Bug 2536770 (CVE-2026-93112)

Summary: CVE-2026-93112 kernel: bpf: Require a BPF cpumask for bpf_cpumask_populate()
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
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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Doc Text:
A flaw was found in the Linux kernel's Berkeley Packet Filter (BPF) component. The `bpf_cpumask_populate()` function incorrectly allows writing to a read-only memory region by accepting borrowed cpumask pointers as writable destinations. This could allow a local attacker to cause a denial of service or potentially escalate privileges by corrupting kernel memory.
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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 2026-09-17 19:30:52 UTC 
In the Linux kernel, the following vulnerability has been resolved:

bpf: Require a BPF cpumask for bpf_cpumask_populate()

bpf_cpumask_populate() writes to its destination with bitmap_copy(), but
the destination is typed as struct cpumask *. That allows the verifier to
accept borrowed cpumask pointers returned by read-only kfuncs, such as
scx_bpf_get_online_cpumask(), as a writable destination.

Make the destination a struct bpf_cpumask * so populate follows the same
ownership rule as the other mutating cpumask kfuncs. Query kfuncs continue
to accept const struct cpumask * inputs.
Comment 1 gkamathe 2026-09-19 16:09:02 UTC 
Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-93112.mbox