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.
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.
Metrics
Affected Vendors & Products
Advisories
No advisories yet.
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Thu, 17 Sep 2026 16:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| 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. | |
| Title | bpf: Reject negative optlen in cgroup getsockopt hook | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
|
Projects
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MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-09-17T16:06:49.081Z
Reserved: 2026-09-11T19:38:34.790Z
Link: CVE-2026-90157
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-09-17T17:17:08.817
Modified: 2026-09-17T17:17:08.817
Link: CVE-2026-90157
Redhat
No data.
OpenCVE Enrichment
No data.
Weaknesses
No weakness.