From: Lennart Poettering <lennart@poettering.net>
Date: Wed, 17 Jan 2018 11:00:12 +0000 (+0100)
Subject: fs-util: extra chase_symlink() safety check on "path" parameter
X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=commitdiff_plain;h=d24d415d801b89ff2804e82c62209436fc3a3a25;p=elogind.git

fs-util: extra chase_symlink() safety check on "path" parameter

It's not clear what an empty "path" is even supposed to mean, hence
refuse.
---

diff --git a/src/basic/fs-util.c b/src/basic/fs-util.c
index 7a05e22ea..bbc464e31 100644
--- a/src/basic/fs-util.c
+++ b/src/basic/fs-util.c
@@ -652,6 +652,9 @@ int chase_symlinks(const char *path, const char *original_root, unsigned flags,
         if ((flags & (CHASE_NONEXISTENT|CHASE_OPEN)) == (CHASE_NONEXISTENT|CHASE_OPEN))
                 return -EINVAL;
 
+        if (isempty(path))
+                return -EINVAL;
+
         /* This is a lot like canonicalize_file_name(), but takes an additional "root" parameter, that allows following
          * symlinks relative to a root directory, instead of the root of the host.
          *