From: Karel Zak <kzak@redhat.com>
Date: Fri, 20 Apr 2012 13:06:57 +0000 (+0200)
Subject: namei: fix relative symlinks evaluation
X-Git-Tag: v2.22-rc1~509
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=89394013f620338863312d069a9b2ac5ba2abf65;p=thirdparty%2Futil-linux.git

namei: fix relative symlinks evaluation

Fedora 17 (/bin is symlink to /usr/bin):

	[root@intel ~]# /bin/namei /bin/namei
	f: /bin/namei
	 d /
	 l bin -> usr/bin
	usr - No such file or directory

Reported-by: Jan Stancek <jstancek@redhat.com>
Signed-off-by: Karel Zak <kzak@redhat.com>
---

diff --git a/misc-utils/namei.c b/misc-utils/namei.c
index 9b8ede901a..b15d4f7b65 100644
--- a/misc-utils/namei.c
+++ b/misc-utils/namei.c
@@ -180,6 +180,7 @@ readlink_to_namei(struct namei *nm, const char *path)
 {
 	char sym[PATH_MAX];
 	ssize_t sz;
+	int isrel = 0;
 
 	sz = readlink(path, sym, sizeof(sym));
 	if (sz < 1)
@@ -187,20 +188,26 @@ readlink_to_namei(struct namei *nm, const char *path)
 	if (*sym != '/') {
 		char *p = strrchr(path, '/');
 
-		nm->relstart = p ? p - path : 0;
-		if (nm->relstart)
+		if (p) {
+			isrel = 1;
+			nm->relstart = p ? p - path : 0;
 			sz += nm->relstart + 1;
+		}
 	}
 	nm->abslink = xmalloc(sz + 1);
 
-	if (*sym != '/' && nm->relstart) {
+	if (*sym != '/' && isrel) {
 		/* create the absolute path from the relative symlink */
 		memcpy(nm->abslink, path, nm->relstart);
 		*(nm->abslink + nm->relstart) = '/';
 		nm->relstart++;
 		memcpy(nm->abslink + nm->relstart, sym, sz - nm->relstart);
 	} else
+		/* - absolute link (foo -> /path/bar)
+		 * - or link without any subdir (foo -> bar)
+		 */
 		memcpy(nm->abslink, sym, sz);
+
 	nm->abslink[sz] = '\0';
 }