From: Chris Down <chris@chrisdown.name>
Date: Wed, 25 Sep 2019 16:09:38 +0000 (+0100)
Subject: util-lib: Don't propagate EACCES from find_binary PATH lookup to caller
X-Git-Tag: v244-rc1~253^2
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=refs%2Fpull%2F13651%2Fhead;p=thirdparty%2Fsystemd.git

util-lib: Don't propagate EACCES from find_binary PATH lookup to caller

On one of my test machines, test-path-util was failing because the
find_binary("xxxx-xxxx") was returning -EACCES instead of -ENOENT. This
happens because the PATH entry on that host contains a directory which
the user in question doesn't have access to. Typically applications
ignore permission errors when searching through PATH, for example in
bash:

    $ whoami
    cdown
    $ PATH=/root:/bin type sh
    sh is /bin/sh

This behaviour is present on zsh and other shells as well, though. This
patch brings our PATH search behaviour closer to other major Unix tools.
---

diff --git a/src/basic/path-util.c b/src/basic/path-util.c
index 18c7dabbae0..b9544b4bacc 100644
--- a/src/basic/path-util.c
+++ b/src/basic/path-util.c
@@ -651,7 +651,9 @@ int find_binary(const char *name, char **ret) {
                         return 0;
                 }
 
-                last_error = -errno;
+                /* PATH entries which we don't have access to are ignored, as per tradition. */
+                if (errno != EACCES)
+                        last_error = -errno;
         }
 
         return last_error;