From 3db7fa27027110fde92a1b6061fab434fe708e9f Mon Sep 17 00:00:00 2001
From: "kay.sievers@vrfy.org" <kay.sievers@vrfy.org>
Date: Tue, 14 Sep 2004 17:45:48 -0700
Subject: [PATCH] [PATCH] fix udev segfaults with bad permissions file

On Tue, Sep 14, 2004 at 02:53:12PM +0200, Loleslaw wrote:
> Hi,
> Since I started using udev-031 on my gentoo udevstart would just segfault
> (udev-030 worked). As it turned out I had a file in /etc/udev/permissions.d
> with a single space in one line. I've cleaned the file and it works all
> right, but I thought you could be interested.
> I've traced it to function namedev_init_permissions in namedev_parse.c
> I don't know C well enough to suggest a patch.

Yeah, thanks for pointing that out. It only happens if the file ends with
whitespace-only lines. Here is a fix and a test for udev-test.pl to
cover that case.
---
 namedev_parse.c   | 16 ++++++----------
 test/udev-test.pl | 16 ++++++++++++++++
 udev_config.c     |  8 +++-----
 3 files changed, 25 insertions(+), 15 deletions(-)

diff --git a/namedev_parse.c b/namedev_parse.c
index 4bb1a97ce..7e3783320 100644
--- a/namedev_parse.c
+++ b/namedev_parse.c
@@ -182,15 +182,13 @@ static int namedev_parse_rules(char *filename)
 			continue;
 		}
 
-		/* empty line? */
-		if (bufline[0] == '\0' || bufline[0] == '\n')
-			continue;
-
 		/* eat the whitespace */
-		while (isspace(bufline[0])) {
+		while ((count > 0) && isspace(bufline[0])) {
 			bufline++;
 			count--;
 		}
+		if (count == 0)
+			continue;
 
 		/* see if this is a comment */
 		if (bufline[0] == COMMENT_CHARACTER)
@@ -381,15 +379,13 @@ static int namedev_parse_permissions(char *filename)
 			continue;
 		}
 
-		/* empty line? */
-		if (bufline[0] == '\0' || bufline[0] == '\n')
-			continue;
-
 		/* eat the whitespace */
-		while (isspace(bufline[0])) {
+		while ((count > 0) && isspace(bufline[0])) {
 			bufline++;
 			count--;
 		}
+		if (count == 0)
+			continue;
 
 		/* see if this is a comment */
 		if (bufline[0] == COMMENT_CHARACTER)
diff --git a/test/udev-test.pl b/test/udev-test.pl
index 1e7c51e55..9feb28a7b 100644
--- a/test/udev-test.pl
+++ b/test/udev-test.pl
@@ -158,6 +158,22 @@ EOF
  # this is a comment with whitespace before the comment 
 KERNEL="ttyUSB0", NAME="visor"
 
+EOF
+	},
+	{
+		desc		=> "Handle whitespace only lines (and replace kernel name)",
+		subsys		=> "tty",
+		devpath		=> "/class/tty/ttyUSB0",
+		exp_name	=> "whitespace" ,
+		conf		=> <<EOF
+
+ 
+
+ # this is a comment with whitespace before the comment 
+KERNEL="ttyUSB0", NAME="whitespace"
+
+ 
+
 EOF
 	},
 	{
diff --git a/udev_config.c b/udev_config.c
index 20b6c75d3..ba2b3d2b8 100644
--- a/udev_config.c
+++ b/udev_config.c
@@ -161,15 +161,13 @@ static int parse_config_file(void)
 			continue;
 		}
 
-		/* empty line? */
-		if (bufline[0] == '\0' || bufline[0] == '\n')
-			continue;
-
 		/* eat the whitespace */
-		while (isspace(bufline[0])) {
+		while ((count > 0) && isspace(bufline[0])) {
 			bufline++;
 			count--;
 		}
+		if (count == 0)
+			continue;
 
 		/* see if this is a comment */
 		if (bufline[0] == COMMENT_CHARACTER)
-- 
2.30.2