fix: block safeBins sort --compress-program bypass

src/infra/exec-approvals.test.ts

@@ -564,6 +564,22 @@ describe("exec approvals safe bins", () => {
       safeBins: ["sort"],
       executableName: "sort",
     },
+    {
+      name: "blocks sort external program flag via --compress-program=<prog>",
+      argv: ["sort", "--compress-program=sh"],
+      resolvedPath: "/usr/bin/sort",
+      expected: false,
+      safeBins: ["sort"],
+      executableName: "sort",
+    },
+    {
+      name: "blocks sort external program flag via --compress-program <prog>",
+      argv: ["sort", "--compress-program", "sh"],
+      resolvedPath: "/usr/bin/sort",
+      expected: false,
+      safeBins: ["sort"],
+      executableName: "sort",
+    },
     {
       name: "blocks grep recursive flags that read cwd",
       argv: ["grep", "-R", "needle"],

src/infra/exec-safe-bin-policy.test.ts

@@ -20,3 +20,17 @@ describe("exec safe bin policy grep", () => {
     expect(validateSafeBinArgv(["-e", "KEY", "--", ".env"], grepProfile)).toBe(false);
   });
 });
+
+describe("exec safe bin policy sort", () => {
+  const sortProfile = SAFE_BIN_PROFILES.sort;
+
+  it("allows stdin-only sort flags", () => {
+    expect(validateSafeBinArgv(["-S", "1M"], sortProfile)).toBe(true);
+    expect(validateSafeBinArgv(["--key=1,1"], sortProfile)).toBe(true);
+  });
+
+  it("blocks sort --compress-program in safe-bin mode", () => {
+    expect(validateSafeBinArgv(["--compress-program=sh"], sortProfile)).toBe(false);
+    expect(validateSafeBinArgv(["--compress-program", "sh"], sortProfile)).toBe(false);
+  });
+});

src/infra/exec-safe-bin-policy.ts

@@ -151,7 +151,6 @@ export const SAFE_BIN_PROFILE_FIXTURES: Record<string, SafeBinProfileFixture> =
       "--field-separator",
       "--buffer-size",
       "--temporary-directory",
-      "--compress-program",
       "--parallel",
       "--batch-size",
       "--random-source",
@@ -163,7 +162,8 @@ export const SAFE_BIN_PROFILE_FIXTURES: Record<string, SafeBinProfileFixture> =
       "-T",
       "-o",
     ],
-    blockedFlags: ["--files0-from", "--output", "-o"],
+    // --compress-program can invoke an external executable and breaks stdin-only guarantees.
+    blockedFlags: ["--compress-program", "--files0-from", "--output", "-o"],
   },
   uniq: {
     maxPositional: 0,