fix: guard CompletionsHandler against nil params/ref#2502
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A malformed completion/complete request with missing or empty parameters caused a nil pointer dereference in CompletionsHandler, panicking the process. Reject such requests with a clear error before dispatching on Ref.Type. Reported by @manthanghasadiya (GHSA-w4q6-qw23-4rg7). Co-authored-by: manthanghasadiya <68530736+manthanghasadiya@users.noreply.github.com> Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
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Pull request overview
Hardens the MCP completion/complete handler to avoid a nil pointer dereference when clients send malformed completion requests, preventing a process panic (self-DoS) by rejecting requests missing params.ref before dispatching on ref.type.
Changes:
- Added a nil-guard in
CompletionsHandlerforreq,req.Params, andreq.Params.Refwith a clear error return. - Added a table-driven unit test covering
nil req,nil params, andnil refcases.
Show a summary per file
| File | Description |
|---|---|
| pkg/github/server.go | Adds early validation to prevent nil deref when handling completion requests. |
| pkg/github/server_test.go | Adds regression test ensuring malformed completion requests are rejected without panicking. |
Copilot's findings
- Files reviewed: 2/2 changed files
- Comments generated: 1
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
JoannaaKL
approved these changes
May 19, 2026
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A malformed
completion/completerequest with missing or empty parameters caused a nil pointer dereference inCompletionsHandler, panicking the process. This adds a nil-guard that rejects such requests with a clear error before dispatching onRef.Type.Reported by @manthanghasadiya in GHSA-w4q6-qw23-4rg7.
Impact
Still worth fixing as routine hardening.
Changes
pkg/github/server.go: nil-guard onreq,req.Params, andreq.Params.Ref.pkg/github/server_test.go:TestCompletionsHandler_RejectsMissingRefcovering all three nil cases.Validation
script/lint→ 0 issuesscript/test→ all packages pass