From: Cong Wang <xiyou.wangcong@gmail.com>
Date: Wed, 20 Jun 2012 08:32:00 +0000 (+0800)
Subject: lib/sysfs: check if cxt->dir_path is NULL in sysfs_readlink()
X-Git-Tag: v2.22-rc1~251
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=cffee0de0cf7c0d44323a830beb313d5ae18247d;p=thirdparty%2Futil-linux.git

lib/sysfs: check if cxt->dir_path is NULL in sysfs_readlink()

cxt->dir_path could be NULL, for example, when sysfs_init() fails,
check this before calling readlink()/readlink_at().

Cc: Karel Zak <kzak@redhat.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
---

diff --git a/lib/sysfs.c b/lib/sysfs.c
index 312191f034..b4fb7cdda6 100644
--- a/lib/sysfs.c
+++ b/lib/sysfs.c
@@ -220,6 +220,9 @@ static int sysfs_open(struct sysfs_cxt *cxt, const char *attr)
 ssize_t sysfs_readlink(struct sysfs_cxt *cxt, const char *attr,
 		   char *buf, size_t bufsiz)
 {
+	if (!cxt->dir_path)
+		return -1;
+
 	if (attr)
 		return readlink_at(cxt->dir_fd, cxt->dir_path, attr, buf, bufsiz);