CVE-2024-27050 Information

Description

In the Linux kernel the following vulnerability has been resolved:

libbpf: Use OPTS_SET() macro in bpf_xdp_query()

When the feature_flags and xdp_zc_max_segs fields were added to the libbpf bpf_xdp_query_opts the code writing them did not use the OPTS_SET() macro. This causes libbpf to write to those fields unconditionally which means that programs compiled against an older version of libbpf (with a smaller size of the bpf_xdp_query_opts struct) will have its stack corrupted by libbpf writing out of bounds.

The patch adding the feature_flags field has an early bail out if the feature_flags field is not part of the opts struct (via the OPTS_HAS) macro but the patch adding xdp_zc_max_segs does not. For consistency this fix just changes the assignments to both fields to use the OPTS_SET() macro.

Reference

https://git.kernel.org/stable/c/fa5bef5e80c6a3321b2b1a7070436f3bc5daf07c https://git.kernel.org/stable/c/682ddd62abd4bdcee7584246903e7a2df005fe0d https://git.kernel.org/stable/c/cd3be9843247edb8fc6fcd8d8237cbce2bc19f5e https://git.kernel.org/stable/c/92a871ab9fa59a74d013bc04f321026a057618e7