From 4c88e07676787bd2d47bcf369a501a881c025a82 Mon Sep 17 00:00:00 2001
From: Alexandre Daubois <alex.daubois@gmail.com>
Date: Thu, 4 Sep 2025 16:38:45 +0200
Subject: [PATCH] Fix GH-19685: Segfault when bzip2 filter has invalid
 parameters

---
 NEWS                                         |  4 ++
 ext/bz2/bz2_filter.c                         |  8 ++++
 ext/bz2/tests/bug72447.phpt                  |  2 +
 ext/bz2/tests/bz2_filter_invalid_params.phpt | 46 ++++++++++++++++++++
 4 files changed, 60 insertions(+)
 create mode 100644 ext/bz2/tests/bz2_filter_invalid_params.phpt

diff --git a/NEWS b/NEWS
index b2b2dccd1cde2..ddfd5562ea145 100644
--- a/NEWS
+++ b/NEWS
@@ -12,6 +12,10 @@ PHP                                                                        NEWS
   . Fixed bug GH-19613 (Stale array iterator pointer). (ilutov)
   . Fixed bug GH-19679 (zend_ssa_range_widening may fail to converge). (Arnaud)
 
+- Bz2:
+  . Fixed bug GH-19685 (Segfault when bzip2 filter has invalid parameters).
+    (alexandre-daubois)
+
 - Date:
   . Fixed date_sunrise() and date_sunset() with partial-hour UTC offset.
     (ilutov)
diff --git a/ext/bz2/bz2_filter.c b/ext/bz2/bz2_filter.c
index 9b3480b4a5ca9..be9732a4e8c72 100644
--- a/ext/bz2/bz2_filter.c
+++ b/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;
 					}
diff --git a/ext/bz2/tests/bug72447.phpt b/ext/bz2/tests/bug72447.phpt
index 11f3bd9136b54..0738d25b99eed 100644
--- a/ext/bz2/tests/bug72447.phpt
+++ b/ext/bz2/tests/bug72447.phpt
@@ -17,3 +17,5 @@ unlink('testfile');
 ?>
 --EXPECTF--
 Warning: stream_filter_append(): Invalid parameter given for number of blocks to allocate (0) in %s%ebug72447.php on line %d
+
+Warning: stream_filter_append(): Unable to create or locate filter "bzip2.compress" in %s%ebug72447.php on line %d
diff --git a/ext/bz2/tests/bz2_filter_invalid_params.phpt b/ext/bz2/tests/bz2_filter_invalid_params.phpt
new file mode 100644
index 0000000000000..9b30340d1ba88
--- /dev/null
+++ b/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)