From: Miklos Szeredi <miklos@szeredi.hu>
Date: Mon, 8 Nov 2010 15:06:37 +0000 (+0100)
Subject: Fix fuse_buf_copy() if already at the end of the buffers
X-Git-Tag: fuse_2_9_0~98
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=7d878eb13a9b1e0e1a428c1ead2733b8453a3bb7;p=qemu-gpiodev%2Flibfuse.git

Fix fuse_buf_copy() if already at the end of the buffers
---

diff --git a/ChangeLog b/ChangeLog
index 5ce455c..6b42706 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -16,6 +16,8 @@
 	with this option then "fusermount -u" will fail if umount(8)
 	doesn't support the --fake and --no-canonicalize options.
 
+	* Fix fuse_buf_copy() if already at the end of the buffers
+
 2010-10-14  Miklos Szeredi <miklos@szeredi.hu>
 
 	* Use LTLIBICONV when linking libfuse.  This fixes building against
diff --git a/lib/buffer.c b/lib/buffer.c
index 8940edd..0006cbf 100644
--- a/lib/buffer.c
+++ b/lib/buffer.c
@@ -232,7 +232,10 @@ static ssize_t fuse_buf_copy_one(const struct fuse_buf *dst, size_t dst_off,
 
 static const struct fuse_buf *fuse_bufvec_current(struct fuse_bufvec *bufv)
 {
-	return &bufv->buf[bufv->idx];
+	if (bufv->idx < bufv->count)
+		return &bufv->buf[bufv->idx];
+	else
+		return NULL;
 }
 
 static int fuse_bufvec_advance(struct fuse_bufvec *bufv, size_t len)
@@ -259,11 +262,18 @@ ssize_t fuse_buf_copy(struct fuse_bufvec *dstv, struct fuse_bufvec *srcv,
 	for (;;) {
 		const struct fuse_buf *src = fuse_bufvec_current(srcv);
 		const struct fuse_buf *dst = fuse_bufvec_current(dstv);
-		size_t src_len = src->size - srcv->off;
-		size_t dst_len = dst->size - dstv->off;
-		size_t len = min_size(src_len, dst_len);
+		size_t src_len;
+		size_t dst_len;
+		size_t len;
 		ssize_t res;
 
+		if (src == NULL || dst == NULL)
+			break;
+
+		src_len = src->size - srcv->off;
+		dst_len = dst->size - dstv->off;
+		len = min_size(src_len, dst_len);
+
 		res = fuse_buf_copy_one(dst, dstv->off, src, srcv->off, len, flags);
 		if (res < 0) {
 			if (!copied)