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
• https://git.kernel.org/stable/c/d02a12b4085ffe41ea750b1007f7a9c7aee2875a
• https://git.kernel.org/stable/c/e6fbf0eba87f50084d67508898f6ad6fc7ff1ba2
• https://git.kernel.org/stable/c/f68671b1a98d426c57864bd457c125fee14ac1a5