Bug 2536785 (CVE-2026-93144)

Summary: CVE-2026-93144 kernel: bpf: Reject writes through untrusted BTF pointers
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: low Docs Contact:
Priority: low    
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 Berkeley Packet Filter (BPF) subsystem. The `check_ptr_to_btf_access()` function, which is responsible for validating memory access through BPF Type Format (BTF) pointers, incorrectly allowed certain program-type callbacks to bypass the intended read-only policy for untrusted BTF pointers. This oversight could enable a local attacker to perform unauthorized write operations, potentially leading to privilege escalation within the system.
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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 19:33:12 UTC 
In the Linux kernel, the following vulnerability has been resolved:

bpf: Reject writes through untrusted BTF pointers

check_ptr_to_btf_access() lets program-type btf_struct_access callbacks
validate writes before the default BTF access path rejects non-read
accesses. That bypasses the read-only policy for untrusted BTF pointers
created by helpers such as bpf_rdonly_cast().

Reject non-read accesses through PTR_UNTRUSTED BTF pointers at the
common entry point, before the callback branch to handle all cases.
Comment 1 gkamathe 2026-09-18 19:49:42 UTC 
Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-93144.mbox