From e17ff7ab5115b80f0d2bd4989cd31889bd54fbb1 Mon Sep 17 00:00:00 2001

From: Lennart Poettering <lennart@poettering.net>

Date: Wed, 9 Jul 2014 19:20:58 +0200

Subject: [PATCH] sysusers: don't allow user names longer than UT_NAMESIZE

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As pointed out by Miloslav Trmač it might be a good idea to make sure

that usernames stay with in the utmp-defined limits.

(cherry picked from commit 932ad62b84165b0acf690ea34c4b8083657ae244)

---

 man/sysusers.d.xml      | 2 +-

 src/sysusers/sysusers.c | 4 ++++

 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/man/sysusers.d.xml b/man/sysusers.d.xml

index 549b3f6351..40f8715bc0 100644

--- a/man/sysusers.d.xml

+++ b/man/sysusers.d.xml

@@ -142,7 +142,7 @@ m authd input</programlisting>

                         <title>Name</title>

                         <para>The name field specifies the user or

-                        group name. It should be be shorter than 256

+                        group name. It should be be shorter than 31

                         characters and avoid any non-ASCII characters,

                         and not begin with a numeric character. It is

                         strongly recommended to pick user and group

diff --git a/src/sysusers/sysusers.c b/src/sysusers/sysusers.c

index c0af69300a..f3ba8cf7b3 100644

--- a/src/sysusers/sysusers.c

+++ b/src/sysusers/sysusers.c

@@ -24,6 +24,7 @@

 #include <grp.h>

 #include <shadow.h>

 #include <getopt.h>

+#include <utmp.h>

 #include "util.h"

 #include "hashmap.h"

@@ -1095,6 +1096,9 @@ static bool valid_user_group_name(const char *u) {

         if ((size_t) (i-u) > (size_t) sz)

                 return false;

+        if ((size_t) (i-u) > UT_NAMESIZE - 1)

+                return false;

+

         return true;

 }