From: Bart Van Assche <bart.vanassche@wdc.com>
Date: Wed, 22 Aug 2018 16:00:15 +0000 (-0700)
Subject: lib/axmap: Make axmap_new() more robust
X-Git-Tag: fio-3.9~19^2~2
X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=70c0f35624b32a86603c034e28e6b09907868100;p=fio.git

lib/axmap: Make axmap_new() more robust

Return NULL instead of triggering a segmentation fault if calloc() fails.
Note: calling free(NULL) is safe so it is not necessary to check the
free() argument before calling free().

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
---

diff --git a/lib/axmap.c b/lib/axmap.c
index 0d8fbf8d..781a1039 100644
--- a/lib/axmap.c
+++ b/lib/axmap.c
@@ -128,6 +128,8 @@ struct axmap *axmap_new(unsigned long nr_bits)
 
 	axmap->nr_levels = levels;
 	axmap->levels = calloc(axmap->nr_levels, sizeof(struct axmap_level));
+	if (!axmap->levels)
+		goto free_axmap;
 	axmap->nr_bits = nr_bits;
 
 	for (i = 0; i < axmap->nr_levels; i++) {
@@ -137,19 +139,21 @@ struct axmap *axmap_new(unsigned long nr_bits)
 		al->map_size = (nr_bits + BLOCKS_PER_UNIT - 1) >> UNIT_SHIFT;
 		al->map = malloc(al->map_size * sizeof(unsigned long));
 		if (!al->map)
-			goto err;
+			goto free_levels;
 
 		nr_bits = (nr_bits + BLOCKS_PER_UNIT - 1) >> UNIT_SHIFT;
 	}
 
 	axmap_reset(axmap);
 	return axmap;
-err:
+
+free_levels:
 	for (i = 0; i < axmap->nr_levels; i++)
-		if (axmap->levels[i].map)
-			free(axmap->levels[i].map);
+		free(axmap->levels[i].map);
 
 	free(axmap->levels);
+
+free_axmap:
 	free(axmap);
 	return NULL;
 }