chore(crashtracking): Redact unknown memory

Author: bric3

dd-java-agent/agent-crashtracking/src/main/java/datadog/crashtracking/parsers/RedactUtils.java

@@ -54,6 +54,15 @@ public final class RedactUtils {
   private static final Pattern IS_AN_OOP =
       Pattern.compile("(is an oop: )([A-Za-z][A-Za-z0-9$]*(?:\\.[A-Za-z][A-Za-z0-9$]*)*)");
 
+  // Hex-dump bytes in "points into unknown readable memory:" lines.
+  // Two formats produced by os::print_location():
+  //   "memory: 0x<addr> | ff ff ff ff ..."  (Linux/macOS amd64 — address + pipe + bytes)
+  //   "memory: ff ff ff ff ..."              (Linux aarch64    — bytes only)
+  // The address (when present) is kept; only the raw bytes are redacted.
+  private static final Pattern READABLE_MEMORY_HEX_DUMP =
+      Pattern.compile(
+          "(points into unknown readable memory: (?:0x[0-9a-fA-F]+ \\| )?)([0-9a-fA-F]{2}(?: [0-9a-fA-F]{2})*)");
+
   private RedactUtils() {}
 
   /**
@@ -79,6 +88,7 @@ private static String redactLine(String line) {
     line = redactLibraryPath(line);
     line = redactDottedClassOopRef(line);
     line = redactOopClassName(line);
+    line = redactReadableMemoryHexDump(line);
     return line;
   }
 
@@ -144,6 +154,20 @@ static String redactOopClassName(String line) {
     return replaceAll(IS_AN_OOP, line, m -> m.group(1) + redactDottedClassName(m.group(2)));
   }
 
+  /**
+   * Redacts hex-dump bytes in <code>points into unknown readable memory:</code> lines, keeping the
+   * optional leading address. Handles two formats:
+   *
+   * <ul>
+   *   <li><code>memory: 0x&lt;addr&gt; | ff ff ff ff</code> to <code>memory: 0x&lt;addr&gt; |
+   *       REDACTED</code>
+   *   <li><code>memory: ff ff ff ff</code> to <code>memory: REDACTED</code>
+   * </ul>
+   */
+  static String redactReadableMemoryHexDump(String line) {
+    return replaceAll(READABLE_MEMORY_HEX_DUMP, line, m -> m.group(1) + REDACTED_STRING);
+  }
+
   /**
    * Redacts the package of a slash-separated JVM class name, unless it belongs to a known package.
    * <code>com/company/SomeType</code> to <code>redacted/redacted/SomeType</code>; <code>

dd-java-agent/agent-crashtracking/src/test/java/datadog/crashtracking/parsers/HotspotCrashLogParserTest.java

@@ -115,6 +115,12 @@ public void testRegisterToMemoryMappingMacosAarch64() throws Exception {
         .isEqualTo(
             "0x0000000106c1ccc0: _ZN19TemplateInterpreter13_active_tableE+0 in /redacted/redacted/redacted/redacted/redacted/redacted/redacted/redacted/redacted/server/libjvm.dylib at 0x0000000105efc000");
 
+    // macOS aarch64 uses address+pipe format — address kept, bytes redacted
+    assertThat(mapping)
+        .extractingByKey("x17", STRING)
+        .isEqualTo(
+            "0x0000000100a17cb0 points into unknown readable memory: 0x00000000ffffffff | REDACTED");
+
     // "Top of Stack: (sp=0x...)" and "Instructions: (pc=0x...)" must not leak into register values
     assertThat(mapping).doesNotContainKey("Top of Stack");
     assertThat(mapping)
@@ -154,7 +160,7 @@ public void testRegisterToMemoryMapping() throws Exception {
         .isNotNull()
         .containsEntry(
             "RAX",
-            "0x00007f36ccfbf170 points into unknown readable memory: 0x00007f3600000758 | 58 07 00 00 36 7f 00 00")
+            "0x00007f36ccfbf170 points into unknown readable memory: 0x00007f3600000758 | REDACTED")
         .containsEntry(
             "RSP", "0x00007f35e6253190 is pointing into the stack for thread: 0x00007f36cd96cc80")
         .containsEntry("RDI", "0x0 is NULL")
@@ -183,6 +189,11 @@ public void testRegisterToMultilineMemoryMapping() throws Exception {
         .contains("\n - ---- fields (total size 25 words):")
         .contains(
             "\n - private transient 'name' 'Ljava/lang/String;' @44  \"jdk.internal.misc.Unsafe\"");
+
+    // Linux aarch64 uses bytes-only format (no address prefix before hex dump)
+    assertThat(crashLog.experimental.registerToMemoryMapping)
+        .extractingByKey("R9", STRING)
+        .isEqualTo("0x0000ffff9f686ca4 points into unknown readable memory: REDACTED");
   }
 
   @Test

dd-java-agent/agent-crashtracking/src/test/java/datadog/crashtracking/parsers/RedactUtilsTest.java

@@ -247,4 +247,29 @@ void testRedactRegisterToMemoryMapping_safeValuesUnchanged() {
     assertThat(RedactUtils.redactRegisterToMemoryMapping("0x000000008fd66048 is an unknown value"))
         .isEqualTo("0x000000008fd66048 is an unknown value");
   }
+
+  @Test
+  void testRedactReadableMemoryHexDump_withAddressAndPipe() {
+    // Linux/macOS amd64: address + " | " + bytes — keep address, redact bytes
+    assertThat(
+            RedactUtils.redactReadableMemoryHexDump(
+                "0x0000000100a17cb0 points into unknown readable memory: 0x00000000ffffffff | ff ff ff ff 00 00 00 00"))
+        .isEqualTo(
+            "0x0000000100a17cb0 points into unknown readable memory: 0x00000000ffffffff | REDACTED");
+  }
+
+  @Test
+  void testRedactReadableMemoryHexDump_withoutAddress() {
+    // Linux aarch64: bytes only — redact everything after the colon
+    assertThat(
+            RedactUtils.redactReadableMemoryHexDump(
+                "0x0000ffff9f686ca4 points into unknown readable memory: 06 00 00 00"))
+        .isEqualTo("0x0000ffff9f686ca4 points into unknown readable memory: REDACTED");
+  }
+
+  @Test
+  void testRedactReadableMemoryHexDump_leavesUnrelatedLinesUnchanged() {
+    assertThat(RedactUtils.redactReadableMemoryHexDump("0x00007f37a16e2590 is an unknown value"))
+        .isEqualTo("0x00007f37a16e2590 is an unknown value");
+  }
 }