From: Naohiro Aota <naota@elisp.net>
Date: Thu, 28 Apr 2016 15:41:50 +0000 (+0900)
Subject: cgtop: initialize `ours' to NULL properly (#3139)
X-Git-Tag: v230~120
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=80b2ab4bc00fe18ee4e9f1325bfc7cdd055c6466;p=thirdparty%2Fsystemd.git

cgtop: initialize `ours' to NULL properly (#3139)

Running cgtop on a system, which lacks expecting stat file, results in a
segfault. For example, a system with blkio tree but without cfq io scheduler,
lacks "blkio.io_service_bytes".

When the targeting cgroup's file does not exist, process() returns 0 and
also does not modify `*ret' value (which is `*ours'). As a result,
callers of refresh_one() can have bogus pointer, which result in SEGV.

This patch just properly initialize the variable to NULL.
---

diff --git a/src/cgtop/cgtop.c b/src/cgtop/cgtop.c
index 9c0e82ebb3e..14eb46c8dbd 100644
--- a/src/cgtop/cgtop.c
+++ b/src/cgtop/cgtop.c
@@ -362,7 +362,7 @@ static int refresh_one(
                 Group **ret) {
 
         _cleanup_closedir_ DIR *d = NULL;
-        Group *ours;
+        Group *ours = NULL;
         int r;
 
         assert(controller);