From: Bartosz Golaszewski <bartekgola@gmail.com>
Date: Sun, 5 Nov 2017 20:04:52 +0000 (+0100)
Subject: iter: fix a crash occurring if no GPIO chips are present
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=f4c15c32ac3b87e1c41534735d91f0f65165bf7e;p=qemu-gpiodev%2Flibgpiod.git

iter: fix a crash occurring if no GPIO chips are present

If no GPIO chips are present in the system, we bail out from
gpiod_chip_iter_new() before allocating the chips array. Add a check
in gpiod_chip_iter_free() to avoid calling free() for iter->chips in
that case.

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

diff --git a/src/lib/iter.c b/src/lib/iter.c
index 62a4165..b9ae310 100644
--- a/src/lib/iter.c
+++ b/src/lib/iter.c
@@ -58,8 +58,10 @@ struct gpiod_chip_iter * gpiod_chip_iter_new(void)
 	iter->num_chips = num_chips;
 	iter->offset = 0;
 
-	if (num_chips == 0)
+	if (num_chips == 0) {
+		iter->chips = NULL;
 		return iter;
+	}
 
 	iter->chips = calloc(num_chips, sizeof(*iter->chips));
 	if (!iter->chips)
@@ -108,7 +110,9 @@ void gpiod_chip_iter_free_noclose(struct gpiod_chip_iter *iter)
 			gpiod_chip_close(iter->chips[i]);
 	}
 
-	free(iter->chips);
+	if (iter->chips)
+		free(iter->chips);
+
 	free(iter);
 }