CVE-2025-40169 - bpf: Reject negative offsets for ALU ops

CVE ID : CVE-2025-40169 Published : Nov. 12, 2025, 11:15 a.m. | 1 hour, 30 minutes ago Description : In the Linux kernel, the following vulnerability has been resolved: bpf: Reject negative offsets for ALU ops When verifying BPF programs, the check_alu_op() function validates instructions with ALU operations. The 'offset' field in these instructions is a signed 16-bit integer. The existing check 'insn->off > 1' was intended to ensure the offset is either 0, or 1 for BPF_MOD/BPF_DIV. However, because 'insn->off' is signed, this check incorrectly accepts all negative values (e.g., -1). This commit tightens the validation by changing the condition to '(insn->off != 0 && insn->off != 1)'. This ensures that any value other than the explicitly permitted 0 and 1 is rejected, hardening the verifier against malformed BPF programs. Severity: 0.0 | NA Visit the link for more details, such as CVSS details, affected products, timeline, and more...