CVE-2026-23140

Description

In the Linux kernel, the following vulnerability has been resolved:bpf, test_run: Subtract size of xdp_frame from allowed metadata sizeThe xdp_frame structure takes up part of the XDP frame headroom,limiting the size of the metadata. However, in bpf_test_run, we donttake this into account, which makes it possible for userspace to supplya metadata size that is too large (taking up the entire headroom).If userspace supplies such a large metadata size in live packet mode,the xdp_update_frame_from_buff() call in xdp_test_run_init_page() callwill fail, after which packet transmission proceeds with anuninitialised frame structure, leading to the usual Bad Stuff.The commit in the Fixes tag fixed a related bug where the second checkin xdp_update_frame_from_buff() could fail, but did not add anyadditional constraints on the metadata size. Complete the fix by addingan additional check on the metadata size. Reorder the checks slightly tomake the logic clearer and add a comment.

Risk Information

Associated Vulnerability

Patch Details

References

https://nvd.nist.gov/vuln/detail/CVE-2023-1234
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-1234