From: Theodore Ts'o <tytso@mit.edu>
Date: Sat, 7 Jul 2007 22:32:26 +0000 (-0400)
Subject: Fix bug which could cause libblkid to loop forever
X-Git-Tag: v1.40.1~8
X-Git-Url: https://git.whamcloud.com/?a=commitdiff_plain;h=ac7dd696d60a2cb6d27c2c4855fefc7b26a26d72;p=tools%2Fe2fsprogs.git

Fix bug which could cause libblkid to loop forever

When revalidating a partition where there is obsolete information in
/etc/blkid.tab, we end up freeing a the type tag without clearing
dev->bid_type, causing blkid_verify() to loop forever.

Addresses-Debian-Bug: #432052

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
---

diff --git a/lib/blkid/tag.c b/lib/blkid/tag.c
index 57277cd..44dd86d 100644
--- a/lib/blkid/tag.c
+++ b/lib/blkid/tag.c
@@ -132,6 +132,7 @@ int blkid_set_tag(blkid_dev dev, const char *name,
 {
 	blkid_tag	t = 0, head = 0;
 	char		*val = 0;
+	char		**dev_var = 0;
 
 	if (!dev || !name)
 		return -BLKID_ERR_PARAM;
@@ -139,6 +140,18 @@ int blkid_set_tag(blkid_dev dev, const char *name,
 	if (!(val = blkid_strndup(value, vlength)) && value)
 		return -BLKID_ERR_MEM;
 
+	/* 
+	 * Certain common tags are linked directly to the device struct
+	 * We need to know what they are before we do anything else because
+	 * the function name parameter might get freed later on.
+	 */
+	if (!strcmp(name, "TYPE"))
+		dev_var = &dev->bid_type;
+	else if (!strcmp(name, "LABEL"))
+		dev_var = &dev->bid_label;
+	else if (!strcmp(name, "UUID"))
+		dev_var = &dev->bid_uuid;
+
 	t = blkid_find_tag_dev(dev, name);
 	if (!value) {
 		if (t)
@@ -182,12 +195,8 @@ int blkid_set_tag(blkid_dev dev, const char *name,
 	}
 	
 	/* Link common tags directly to the device struct */
-	if (!strcmp(name, "TYPE"))
-		dev->bid_type = val;
-	else if (!strcmp(name, "LABEL"))
-		dev->bid_label = val;
-	else if (!strcmp(name, "UUID"))
-		dev->bid_uuid = val;
+	if (dev_var)
+		*dev_var = val;
 		
 	if (dev->bid_cache)
 		dev->bid_cache->bic_flags |= BLKID_BIC_FL_CHANGED;