Added check for small ZEMD_MM_SEG_SIZE

diff --git a/Zend/zend_alloc.c b/Zend/zend_alloc.c
index 8ea0444669debbc9977e97daaecb42338fae2f96..d758b8bbf4ad87fcec8220ba45ec70860dcb5b9e 100644 (file)
--- a/Zend/zend_alloc.c
+++ b/Zend/zend_alloc.c
@@ -1153,6 +1153,9 @@ ZEND_API zend_mm_heap *zend_mm_startup(void) /* {{{ */
                if (zend_mm_low_bit(seg_size) != zend_mm_high_bit(seg_size)) {
                        fprintf(stderr, "ZEND_MM_SEG_SIZE must be a power of two\n");
                        exit(255);
+               } else if (seg_size < ZEND_MM_ALIGNED_SEGMENT_SIZE + ZEND_MM_ALIGNED_HEADER_SIZE) {
+                       fprintf(stderr, "ZEND_MM_SEG_SIZE is too small\n");
+                       exit(255);
                }
        } else {
                seg_size = ZEND_MM_SEG_SIZE;