Patch for 72837

72837.diff

commit 27b9daa8f58defdfce71163340ff58374cc5eb4f
Author: Stanislav Malyshev <stas@php.net>
Date:   Mon Aug 15 23:17:26 2016 -0700

    Fix bug #72837 - integer overflow in bzdecompress caused heap corruption

diff --git a/ext/bz2/bz2.c b/ext/bz2/bz2.c
index 54b59f7..79ec3ec 100644
--- a/ext/bz2/bz2.c
+++ b/ext/bz2/bz2.c
@@ -574,15 +574,25 @@ static PHP_FUNCTION(bzdecompress)
 		/* compression is better then 2:1, need to allocate more memory */
 		bzs.avail_out = source_len;
 		size = (bzs.total_out_hi32 * (unsigned int) -1) + bzs.total_out_lo32;
+		if (size > INT_MAX) {
+			/* no reason to continue if we're going to drop it anyway */
+			break;
+		}
 		dest = safe_erealloc(dest, 1, bzs.avail_out+1, (size_t) size );
 		bzs.next_out = dest + size;
 	}
 
 	if (error == BZ_STREAM_END || error == BZ_OK) {
 		size = (bzs.total_out_hi32 * (unsigned int) -1) + bzs.total_out_lo32;
+		if (size > INT_MAX) {
+			php_error_docref(NULL TSRMLS_CC, E_WARNING, "Decompressed size too big, max is %d", INT_MAX);
+			efree(dest);
+			RETVAL_LONG(BZ_MEM_ERROR);
+		} else {
 			dest = safe_erealloc(dest, 1, (size_t) size, 1);
 			dest[size] = '\0';
 			RETVAL_STRINGL(dest, (int) size, 0);
+		}
 	} else { /* real error */
 		efree(dest);
 		RETVAL_LONG(error);