CVE-2026-90157 — bpf: Reject negative optlen in cgroup getsockopt hook
In the Linux kernel, the following vulnerability has been resolved: bpf: Reject negative optlen in cgroup getsockopt hook A cgroup getsockopt BPF program can shrink ctx->optle…
Published: 2026-09-17 · CVSS: Unscored
In the Linux kernel, the following vulnerability has been resolved: bpf: Reject negative optlen in cgroup getsockopt hook A cgroup getsockopt BPF program can shrink ctx->optlen after the kernel getsockopt handler has run. The kernel-buffer variant, used by TCP_ZEROCOPY_RECEIVE, only rejects values larger than the original length. If BPF writes a negative optlen, that value is accepted and propagated back to the TCP getsockopt code. It can then be passed to copy_to_sockptr() as a size_t and trigger the hardened usercopy bytes > INT_MAX warning. Reject negative ctx.optlen in __cgroup_bpf_run_filter_getsockopt_kern(), matching the lower-bound validation already present in the sockptr-based getsockopt hook.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7