From 2f55ffdf205451feff0da676aa364faafb7cabe2 Mon Sep 17 00:00:00 2001
From: Christian Prochaska <christian.prochaska@genode-labs.com>
Date: Thu, 20 Aug 2020 16:15:24 +0200
Subject: [PATCH] libc: zero-initialize anonymous memory from 'mmap()'

Fixes #3854
---
 repos/libports/src/lib/libc/file_operations.cc | 1 +
 1 file changed, 1 insertion(+)

diff --git a/repos/libports/src/lib/libc/file_operations.cc b/repos/libports/src/lib/libc/file_operations.cc
index 07b5fd51d5..e892dab551 100644
--- a/repos/libports/src/lib/libc/file_operations.cc
+++ b/repos/libports/src/lib/libc/file_operations.cc
@@ -422,6 +422,7 @@ __SYS_(void *, mmap, (void *addr, ::size_t length,
 			errno = ENOMEM;
 			return MAP_FAILED;
 		}
+		::memset(start, 0, align_addr(length, PAGE_SHIFT));
 		mmap_registry()->insert(start, length, 0);
 		return start;
 	}