From: Timo Kokkonen <timo.t.kokkonen@iki.fi>
Date: Tue, 1 Nov 2016 19:02:00 +0000 (+0200)
Subject: onewire_parser: Ensure proper strng NULL handling
X-Git-Url: http://git.itanic.dy.fi/?p=rrdd;a=commitdiff_plain;h=247b9c8873ea60fd3d67c85eb730e088a35cdac5

onewire_parser: Ensure proper strng NULL handling

strncpy() call length argument must be one less than the actual buffer
length. The final byte in buffer must be NULL, in case strncpy does
not fill it with NULL itself.

Signed-off-by: Timo Kokkonen <timo.t.kokkonen@iki.fi>
---

diff --git a/onewire_parser.c b/onewire_parser.c
index 54ba71f..b33ee9f 100644
--- a/onewire_parser.c
+++ b/onewire_parser.c
@@ -117,6 +117,9 @@ static int make_uncached(char *path, size_t len)
 	if (strstr(path, "/uncached/"))
 		return 0;
 
+	p1[sizeof(p1) - 1] = '\0';
+	p2[sizeof(p2) - 1] = '\0';
+
 	/*
 	 * Naively assume the "uncached" string can be put after the
 	 * first slash
@@ -130,8 +133,8 @@ static int make_uncached(char *path, size_t len)
 	*p = 0;
 	p++;
 
-	strncpy(p1, path, sizeof(p1));
-	strncpy(p2, p, sizeof(p2));
+	strncpy(p1, path, sizeof(p1) - 1);
+	strncpy(p2, p, sizeof(p2) - 1);
 	snprintf(path, len, "%s/uncached/%s", p1, p2);
 
 	return 0;