CVE-2026-90157

Description

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.

References

• https://git.kernel.org/stable/c/1b5aacd5b2419b0790e955e466d389a61c79b4b1
• https://git.kernel.org/stable/c/2bdbe00454200fcb0110f31eeca8d906a3515e74
• https://git.kernel.org/stable/c/31a89af4f513d750fec196e2bb6195a7d4473e9f
• https://git.kernel.org/stable/c/554ba7195c4108726450e24480c8449990c2268c
• https://git.kernel.org/stable/c/5b09d984b38b018b123c3a9e02a96bbc6468dbe5