From: Bartosz Golaszewski <bartekgola@gmail.com>
Date: Fri, 20 Oct 2017 09:00:45 +0000 (+0200)
Subject: helpers: fix a crash in gpiod_chip_find_line()
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=0a2586e956d4348386899ee6af949abf27cfe66b;p=qemu-gpiodev%2Flibgpiod.git

helpers: fix a crash in gpiod_chip_find_line()

The name of a line can be NULL in which case we must check it and skip
the call to strcmp() to avoid a NULL pointer dereference.

Signed-off-by: Bartosz Golaszewski <bartekgola@gmail.com>
---

diff --git a/src/lib/helpers.c b/src/lib/helpers.c
index f977ca6..4de9143 100644
--- a/src/lib/helpers.c
+++ b/src/lib/helpers.c
@@ -107,13 +107,15 @@ gpiod_chip_find_line(struct gpiod_chip *chip, const char *name)
 {
 	struct gpiod_line_iter iter;
 	struct gpiod_line *line;
+	const char *tmp;
 
 	gpiod_line_iter_init(&iter, chip);
 	gpiod_foreach_line(&iter, line) {
 		if (gpiod_line_iter_err(&iter))
 			return NULL;
 
-		if (strcmp(gpiod_line_name(line), name) == 0)
+		tmp = gpiod_line_name(line);
+		if (tmp && strcmp(tmp, name) == 0)
 			return line;
 	}
 
diff --git a/tests/tests-line.c b/tests/tests-line.c
index 86ebc96..220255d 100644
--- a/tests/tests-line.c
+++ b/tests/tests-line.c
@@ -327,6 +327,18 @@ TEST_DEFINE(line_find_not_found,
 	    "gpiod_line_find() - not found",
 	    TEST_FLAG_NAMED_LINES, { 16, 16, 32, 16 });
 
+static void line_find_unnamed_lines(void)
+{
+	TEST_CLEANUP(test_line_close_chip) struct gpiod_line *line = NULL;
+
+	line = gpiod_line_find("gpio-mockup-C-12");
+	TEST_ASSERT_NULL(line);
+	TEST_ASSERT_ERRNO_IS(ENOENT);
+}
+TEST_DEFINE(line_find_unnamed_lines,
+	    "gpiod_line_find() - unnamed lines",
+	    0, { 16, 16, 32, 16 });
+
 static void line_direction(void)
 {
 	TEST_CLEANUP(test_close_chip) struct gpiod_chip *chip = NULL;