fix(pdf): reject unsafe page numbers before analysis (#105315)

* fix(pdf): reject unsafe page numbers before analysis

* test(pdf): bound unsafe page range regression

src/agents/tools/pdf-tool.helpers.test.ts

@@ -79,6 +79,17 @@ describe("parsePageRange", () => {
     expect(() => parsePageRange("1,2.5", 20)).toThrow('Invalid page number: "2.5"');
   });
 
+  it("throws on unsafe integer page numbers and ranges", () => {
+    const unsafePage = String(Number.MAX_SAFE_INTEGER + 1);
+    const maxPages = 20;
+    expect(() => parsePageRange(unsafePage, maxPages)).toThrow(
+      `Invalid page number: "${unsafePage}"`,
+    );
+    expect(() => parsePageRange(`1-${unsafePage}`, maxPages)).toThrow(
+      `Invalid page range: "${unsafePage}"`,
+    );
+  });
+
   it("throws on invalid range (start > end)", () => {
     expect(() => parsePageRange("5-3", 20)).toThrow("Invalid page range");
   });

src/agents/tools/pdf-tool.helpers.ts

@@ -47,6 +47,14 @@ export function providerSupportsNativePdf(provider: string): boolean {
 }
 
 /** Parses a page range string into sorted, unique, 1-based page numbers within `maxPages`. */
+function readPageNumber(value: string, errorLabel: string): number {
+  const parsed = Number(value);
+  if (!Number.isSafeInteger(parsed) || parsed < 1) {
+    throw new Error(`${errorLabel}: "${value}"`);
+  }
+  return parsed;
+}
+
 export function parsePageRange(range: string, maxPages: number): number[] {
   const pages = new Set<number>();
   const parts = range.split(",").map((p) => p.trim());
@@ -56,9 +64,9 @@ export function parsePageRange(range: string, maxPages: number): number[] {
     }
     const dashMatch = /^(\d+)\s*-\s*(\d+)$/.exec(part);
     if (dashMatch) {
-      const start = Number(dashMatch[1]);
-      const end = Number(dashMatch[2]);
-      if (!Number.isFinite(start) || !Number.isFinite(end) || start < 1 || end < start) {
+      const start = readPageNumber(dashMatch[1] ?? "", "Invalid page range");
+      const end = readPageNumber(dashMatch[2] ?? "", "Invalid page range");
+      if (end < start) {
         throw new Error(`Invalid page range: "${part}"`);
       }
       for (let i = start; i <= Math.min(end, maxPages); i++) {
@@ -68,10 +76,7 @@ export function parsePageRange(range: string, maxPages: number): number[] {
       if (!/^\d+$/.test(part)) {
         throw new Error(`Invalid page number: "${part}"`);
       }
-      const num = Number(part);
-      if (!Number.isFinite(num) || num < 1) {
-        throw new Error(`Invalid page number: "${part}"`);
-      }
+      const num = readPageNumber(part, "Invalid page number");
       if (num <= maxPages) {
         pages.add(num);
       }

src/agents/tools/pdf-tool.test.ts

@@ -625,8 +625,9 @@ describe("createPdfTool", () => {
   it.each([
     ["1.5", "1.5"],
     ["1,2.5", "2.5"],
+    [`1,${String(Number.MAX_SAFE_INTEGER + 1)}`, String(Number.MAX_SAFE_INTEGER + 1)],
   ])(
-    "rejects fractional page selection %s before loading or fallback extraction",
+    "rejects invalid page selection %s before loading or fallback extraction",
     async (pages, invalidPage) => {
       await withTempPdfAgentDir(async (agentDir) => {
         const { loadSpy } = await stubPdfToolInfra(agentDir, {