{"record":{"id":"0c46e3a95d9fe975","repo":"java-native-access/jna","slug":"missing-variable-value-separator-in","errorCode":null,"errorMessage":"Missing variable value separator in ","messagePattern":"Missing variable value separator in ","errorType":"exception","errorClass":"IllegalArgumentException","httpStatus":null,"severity":"error","filePath":"contrib/platform/src/com/sun/jna/platform/win32/Kernel32Util.java","lineNumber":486,"sourceCode":"     */\n    public static Map<String,String> getEnvironmentVariables(Pointer lpszEnvironmentBlock, long offset) {\n        if (lpszEnvironmentBlock == null) {\n            return null;\n        }\n\n        Map<String,String>  vars=new TreeMap<>();\n        boolean             asWideChars=isWideCharEnvironmentStringBlock(lpszEnvironmentBlock, offset);\n        long                stepFactor=asWideChars ? 2L : 1L;\n        for (long    curOffset=offset; ; ) {\n            String  nvp=readEnvironmentStringBlockEntry(lpszEnvironmentBlock, curOffset, asWideChars);\n            int     len=nvp.length();\n            if (len == 0) { // found the ending '\\0'\n                break;\n            }\n\n            int pos=nvp.indexOf('=');\n            if (pos < 0) {\n                throw new IllegalArgumentException(\"Missing variable value separator in \" + nvp);\n            }\n\n            String  name=nvp.substring(0, pos), value=nvp.substring(pos + 1);\n            vars.put(name, value);\n\n            curOffset += (len + 1 /* skip the ending '\\0' */) * stepFactor;\n        }\n\n        return vars;\n    }\n\n    /**\n     * @param lpszEnvironmentBlock The environment block as received from the\n     * <A HREF=\"https://msdn.microsoft.com/en-us/library/windows/desktop/ms683187(v=vs.85).aspx\">GetEnvironmentStrings</A>\n     * function\n     * @param offset Offset within the block to look for the entry\n     * @param asWideChars If {@code true} then the block contains {@code wchar_t}\n     * instead of &quot;plain old&quot; {@code char}s","sourceCodeStart":468,"sourceCodeEnd":504,"githubUrl":"https://github.com/java-native-access/jna/blob/d036ad9781adad4b66693e8fa7098e4ac665e0a3/contrib/platform/src/com/sun/jna/platform/win32/Kernel32Util.java#L468-L504","documentation":"Kernel32Util.getEnvironmentVariables throws this IllegalArgumentException when an entry of the remote/process environment block has no '=' separator between the variable name and value. Well-formed environment entries always contain '=', so a missing separator means a malformed environment block was read.","triggerScenarios":"Reading another process's environment block (via getEnvironmentVariables on a Process handle) where the memory layout was parsed incorrectly — commonly a Unicode/ANSI (stepFactor) mismatch or corrupted entry boundaries; entries like empty or malformed strings returned by the target process.","commonSituations":"Cross-architecture (32/64-bit) reading of PEB environment; reading a process whose environment was modified while being scanned; passing a step size that misaligns string boundaries.","solutions":["Ensure the correct string width (stepFactor) is used for the target process (Unicode vs ANSI, 32 vs 64-bit)","Re-read the environment block atomically; the target may have mutated it during the scan (retry, possibly with the process suspended)","Validate the base address of the environment block (ProcessParameters.Environment) before iterating; a wrong base yields garbage entries","If an entry is genuinely malformed, wrap the call in try-catch for IllegalArgumentException and skip/log the offending environment"],"exampleFix":"// before\nMap<String,String> env = Kernel32Util.getEnvironmentVariables(hProcess, envAddress);\n// after\ntry {\n    Map<String,String> env = Kernel32Util.getEnvironmentVariables(hProcess, envAddress);\n} catch (IllegalArgumentException e) {\n    // malformed environment block (mutated or wrong string width)\n    log.warn(\"Failed to read environment block: \" + e.getMessage());\n}","handlingStrategy":"try-catch","validationCode":null,"typeGuard":null,"tryCatchPattern":"try {\n    Map<String,String> env = Kernel32Util.getEnvironmentVariables(hProcess, address);\n} catch (IllegalArgumentException e) {\n    if (e.getMessage().startsWith(\"Missing variable value separator\")) {\n        // environment block mutated or wrong string width: suspend target and retry\n        Map<String,String> env = Kernel32Util.getEnvironmentVariables(hProcess, address);\n    } else {\n        throw e;\n    }\n}","preventionTips":["Use the correct string width/stepFactor for the target process (Unicode 2-byte entries)","Read the environment block while the target process is suspended to avoid mid-scan mutation","Verify the environment block base address from ProcessParameters before iterating"],"tags":["java","win32","kernel32","environment-variables","parsing"],"backgroundTag":"invalid-argument-format","analyzedSha":"d036ad9781adad4b66693e8fa7098e4ac665e0a3","analyzedAt":"2026-09-12T06:50:59.239Z","contentChangedAt":"2026-09-12T06:50:59.239Z","schemaVersion":2},"datasetVersion":"2026-09-14T11:17:12.474Z"}