Fixed #42663 (gzinflate() try to allocate all memory with truncated data), not present in HEAD.

3 files changed, 79 insertions, 27 deletions

diff --git a/ext/zlib/tests/gzinflate-bug42663.phpt b/ext/zlib/tests/gzinflate-bug42663.phpt
new file mode 100644
index 0000000000..dd53c78f4e
--- /dev/null
+++ b/ext/zlib/tests/gzinflate-bug42663.phpt
@@ -0,0 +1,23 @@
+--TEST--
+Bug #42663 (gzinflate() try to allocate all memory with truncated $data)
+--SKIPIF--
+<?php if (!extension_loaded("zlib")) print "skip"; ?>
+--FILE--
+<?php
+// build a predictable string
+$string = b'';
+for($i=0; $i<30000; ++$i) $string .= (binary)$i . b' ';
+var_dump(strlen($string));
+// deflate string
+$deflated = gzdeflate($string,9);
+var_dump(strlen($deflated));
+// truncate $deflated string
+$truncated = substr($deflated, 0, 65535);
+var_dump(strlen($truncated));
+// inflate $truncated string (check if it will not eat all memory)
+gzinflate($truncated);
+?>
+--EXPECT--
+int(168890)
+int(66743)
+int(65535)
diff --git a/ext/zlib/tests/gzinflate_length.phpt b/ext/zlib/tests/gzinflate_length.phpt
new file mode 100644
index 0000000000..436025d13a
--- /dev/null
+++ b/ext/zlib/tests/gzinflate_length.phpt
@@ -0,0 +1,26 @@
+--TEST--
+gzinflate() and $length argument
+--SKIPIF--
+<?php if (!extension_loaded("zlib")) print "skip"; ?>
+--FILE--
+<?php
+$original = b'aaaaaaaaaaaaaaa';
+$packed=gzdeflate($original);
+echo strlen($packed)." ".strlen($original)."\n";
+$unpacked=gzinflate($packed, strlen($original));
+if (strcmp($original,$unpacked)==0) echo "Strings are equal\n";
+
+$unpacked=gzinflate($packed, strlen($original)*10);
+if (strcmp($original,$unpacked)==0) echo "Strings are equal\n";
+
+$unpacked=gzinflate($packed, 1);
+if ($unpacked === false) echo "Failed (as expected)\n";
+?>
+--EXPECTF--
+5 15
+Strings are equal
+Strings are equal
+
+Warning: gzinflate(): insufficient memory in %s on line %d
+Failed (as expected)
+
diff --git a/ext/zlib/zlib.c b/ext/zlib/zlib.c
index 68d7db80b3..d78589e605 100644
--- a/ext/zlib/zlib.c
+++ b/ext/zlib/zlib.c
@@ -620,6 +620,20 @@ static PHP_FUNCTION(gzinflate)
 	}
 	plength = limit;
 
+	stream.zalloc = (alloc_func) Z_NULL;
+	stream.zfree = (free_func) Z_NULL;
+	stream.opaque = Z_NULL;
+	stream.avail_in = data_len + 1; /* there is room for \0 */
+	stream.next_in = (Bytef *) data;
+	stream.total_out = 0;
+
+	/* init with -MAX_WBITS disables the zlib internal headers */
+	status = inflateInit2(&stream, -MAX_WBITS);
+	if (status != Z_OK) {
+		php_error_docref(NULL TSRMLS_CC, E_WARNING, "%s", zError(status));
+		RETURN_FALSE;
+	}
+
 	/*
 	  stream.avail_out wants to know the output data length
 	  if none was given as a parameter
@@ -627,43 +641,32 @@ static PHP_FUNCTION(gzinflate)
 	  doubling it whenever it wasn't big enough
 	  that should be enaugh for all real life cases	
 	*/
-
-	stream.zalloc = (alloc_func) Z_NULL;
-	stream.zfree = (free_func) Z_NULL;
-
 	do {
 		length = plength ? plength : (unsigned long)data_len * (1 << factor++);
 		s2 = (char *) erealloc(s1, length);
 
-		if (!s2 && s1) {
-			efree(s1);
+		if (!s2) {
+			if (s1) {
+				efree(s1);
+			}
+			inflateEnd(&stream);
 			RETURN_FALSE;
 		}
+		s1 = s2;
 
-		stream.next_in = (Bytef *) data;
-		stream.avail_in = (uInt) data_len + 1; /* there is room for \0 */
+		stream.next_out = (Bytef *) &s2[stream.total_out];
+		stream.avail_out = length - stream.total_out;
+		status = inflate(&stream, Z_NO_FLUSH);
 
-		stream.next_out = s2;
-		stream.avail_out = (uInt) length;
+	} while ((Z_BUF_ERROR == status || (Z_OK == status && stream.avail_in)) && !plength && factor < maxfactor);
 
-		/* init with -MAX_WBITS disables the zlib internal headers */
-		status = inflateInit2(&stream, -MAX_WBITS);
-		if (status == Z_OK) {
-			status = inflate(&stream, Z_FINISH);
-			if (status != Z_STREAM_END) {
-				inflateEnd(&stream);
-				if (status == Z_OK) {
-					status = Z_BUF_ERROR;
-				}
-			} else {
-				status = inflateEnd(&stream);
-			}
-		}
-		s1 = s2;
-		
-	} while ((status == Z_BUF_ERROR) && (!plength) && (factor < maxfactor));
+	inflateEnd(&stream);
 
-	if (status == Z_OK) {
+	if ((plength && Z_OK == status) || factor >= maxfactor) {
+		status = Z_MEM_ERROR;
+	}
+
+	if (Z_STREAM_END == status || Z_OK == status) {
 		s2 = erealloc(s2, stream.total_out + 1); /* room for \0 */
 		s2[ stream.total_out ] = '\0';
 		RETURN_STRINGL(s2, stream.total_out, 0);