From: Karel Zak <kzak@redhat.com>
Date: Tue, 7 Oct 2014 10:44:34 +0000 (+0200)
Subject: libblkid: zeroize errno on blkid_probe_get_buffer() success
X-Git-Tag: v2.26-rc1~412
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=00749bc366fe6106df918660a92a388cfff4f35f;p=thirdparty%2Futil-linux.git

libblkid: zeroize errno on blkid_probe_get_buffer() success

Since 37f4060225df0591ab8e1dd676dbc8115d900d4f prober functions are
sensitive to errno, it seems more robust to set errno=0 with in
blkid_probe_get_buffer() on success than set the zero on all places
where we call blkid_probe_get_buffer().

Addresses: https://github.com/karelzak/util-linux/issues/119
Signed-off-by: Karel Zak <kzak@redhat.com>
---

diff --git a/libblkid/src/probe.c b/libblkid/src/probe.c
index 4fea3ccb4a..3f7e43bec6 100644
--- a/libblkid/src/probe.c
+++ b/libblkid/src/probe.c
@@ -539,8 +539,10 @@ unsigned char *blkid_probe_get_buffer(blkid_probe pr,
 	struct list_head *p;
 	struct blkid_bufinfo *bf = NULL;
 
-	if (pr->size <= 0)
+	if (pr->size <= 0) {
+		errno = EINVAL;
 		return NULL;
+	}
 
 	if (pr->parent &&
 	    pr->parent->devno == pr->devno &&
@@ -602,6 +604,7 @@ unsigned char *blkid_probe_get_buffer(blkid_probe pr,
 		list_add_tail(&bf->bufs, &pr->buffers);
 	}
 
+	errno = 0;
 	return off ? bf->data + (off - bf->off) : bf->data;
 }