CVE Catalog

CVE-2026-98085

Unknown
Published: Translated: NVD NIST

Summary

In the Linux kernel, the precision backtracking mechanism for BPF_LD | BPF_{IND,ABS} instructions did not handle the implicit exit from a subprogram. This caused backtracking to continue in the caller frame while processing instructions in the callee frame, leading to segmentation faults or unsound state pruning.

Risk Assessment

An attacker could exploit this vulnerability to cause a system crash (segfault) or trick the verifier into accepting unsafe BPF programs, potentially leading to privilege escalation or system integrity compromise.

Recommendation

It is recommended to immediately update the Linux kernel to a version containing the fix that adds handling of the exit edge for ld_{abs,ind} instructions in backtrack_insn().

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: bpf: backtrack_insn(): Handle ld_{abs,ind} subprog exit edge Nicholas Carlini reported a bug in precision backtracking mechanism for BPF_LD | BPF_{IND,ABS} instructions. These instructions are modelled as two branches: - fallthrough; - implicit exit from current subprogram. The implicit exit case was not handled by the backtrack_insn() function. When backtracking such a path backtrack_insn() did not call bt_subprog_enter(), which meant that backtracking continued manipulating precision marks in a caller frame, while looking at instructions in a callee frame. This lead to segmentation faults during verification (see the selftest), or unsound state pruning.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS