Fix GH-19685: Segfault when bzip2 filter has invalid parameters

Author: alexandre-daubois

NEWS

@@ -2,6 +2,10 @@ PHP                                                                        NEWS
 |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
 ?? ??? ????, PHP 8.3.26
 
+- Bz2:
+  . Fixed bug GH-19685 (Segfault when bzip2 filter has invalid parameters).
+    (alexandre-daubois)
+
 - Core:
   . Fixed bug GH-18850 (Repeated inclusion of file with __halt_compiler()
     triggers "Constant already defined" warning). (ilutov)

ext/bz2/bz2_filter.c

@@ -367,6 +367,10 @@ static php_stream_filter *php_bz2_filter_create(const char *filtername, zval *fi
 					zend_long blocks = zval_get_long(tmpzval);
 					if (blocks < 1 || blocks > 9) {
 						php_error_docref(NULL, E_WARNING, "Invalid parameter given for number of blocks to allocate (" ZEND_LONG_FMT ")", blocks);
+						pefree(data->strm.next_in, persistent);
+						pefree(data->strm.next_out, persistent);
+						pefree(data, persistent);
+						return NULL;
 					} else {
 						blockSize100k = (int) blocks;
 					}
@@ -377,6 +381,10 @@ static php_stream_filter *php_bz2_filter_create(const char *filtername, zval *fi
 					zend_long work = zval_get_long(tmpzval);
 					if (work < 0 || work > 250) {
 						php_error_docref(NULL, E_WARNING, "Invalid parameter given for work factor (" ZEND_LONG_FMT ")", work);
+						pefree(data->strm.next_in, persistent);
+						pefree(data->strm.next_out, persistent);
+						pefree(data, persistent);
+						return NULL;
 					} else {
 						workFactor = (int) work;
 					}

ext/bz2/tests/bz2_filter_invalid_params.phpt

@@ -0,0 +1,46 @@
+--TEST--
+GH-19685: bzip2.compress filter with invalid parameters should fail gracefully
+--EXTENSIONS--
+bz2
+--FILE--
+<?php
+$stream = fopen('php://memory', 'w+');
+
+// too low
+$filter = stream_filter_append($stream, 'bzip2.compress', STREAM_FILTER_WRITE, array('blocks' => 0));
+var_dump($filter);
+
+// too high
+$filter = stream_filter_append($stream, 'bzip2.compress', STREAM_FILTER_WRITE, array('blocks' => 10));
+var_dump($filter);
+
+// too low work
+$filter = stream_filter_append($stream, 'bzip2.compress', STREAM_FILTER_WRITE, array('work' => -1));
+var_dump($filter);
+
+// too high work
+$filter = stream_filter_append($stream, 'bzip2.compress', STREAM_FILTER_WRITE, array('work' => 251));
+var_dump($filter);
+
+fclose($stream);
+?>
+--EXPECTF--
+Warning: stream_filter_append(): Invalid parameter given for number of blocks to allocate (0) in %s on line %d
+
+Warning: stream_filter_append(): Unable to create or locate filter "bzip2.compress" in %s on line %d
+bool(false)
+
+Warning: stream_filter_append(): Invalid parameter given for number of blocks to allocate (10) in %s on line %d
+
+Warning: stream_filter_append(): Unable to create or locate filter "bzip2.compress" in %s on line %d
+bool(false)
+
+Warning: stream_filter_append(): Invalid parameter given for work factor (-1) in %s on line %d
+
+Warning: stream_filter_append(): Unable to create or locate filter "bzip2.compress" in %s on line %d
+bool(false)
+
+Warning: stream_filter_append(): Invalid parameter given for work factor (251) in %s on line %d
+
+Warning: stream_filter_append(): Unable to create or locate filter "bzip2.compress" in %s on line %d
+bool(false)