References to Advisories, Solutions, and Tools

By selecting these links, you will be leaving NIST webspace. We have provided these links to other web sites because they may have information that would be of interest to you. No inferences should be drawn on account of other sites being referenced, or not, from this page. There may be other web sites that are more appropriate for your purpose. NIST does not necessarily endorse the views expressed, or concur with the facts presented on these sites. Further, NIST does not endorse any commercial products that may be mentioned on these sites. Please address comments about this page to [email protected].

Change History

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.

https://git.kernel.org/stable/c/21167bf70dbe400563e189ac632258d35eda38b5

https://git.kernel.org/stable/c/3bce44b344040e5eef3d64d38b157c15304c0aab

https://git.kernel.org/stable/c/5017c302ca4b2a45149ad64e058fa2d5623c068f

https://git.kernel.org/stable/c/55c0ced59fe17dee34e9dfd5f7be63cbab207758