From: Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl>
Date: Fri, 11 Dec 2020 15:52:30 +0000 (+0100)
Subject: shared/hostname-setup: leave the terminator byte alone
X-Git-Tag: v248-rc1~491^2~5
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=39ede7cc377dcb057411c80509e5fde8901f20fb;p=thirdparty%2Fsystemd.git

shared/hostname-setup: leave the terminator byte alone

gethostname(3) says it's unspecified whether the string is properly terminated
when the hostname is too long. We created a buffer with one extra byte, and it
seems the intent was to let that byte serve as terminator even if we get an
unterminated string from gethostname().
---

diff --git a/src/shared/hostname-setup.c b/src/shared/hostname-setup.c
index 42a8ada1447..19e528604bd 100644
--- a/src/shared/hostname-setup.c
+++ b/src/shared/hostname-setup.c
@@ -22,7 +22,7 @@ static int sethostname_idempotent_full(const char *s, bool really) {
 
         assert(s);
 
-        if (gethostname(buf, sizeof(buf)) < 0)
+        if (gethostname(buf, sizeof(buf) - 1) < 0)
                 return -errno;
 
         if (streq(buf, s))