Patch "fuse: listxattr: verify xattr list" has been added to the 4.7-stable tree

This is a note to let you know that I've just added the patch titled

fuse: listxattr: verify xattr list

to the 4.7-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
fuse-listxattr-verify-xattr-list.patch
and it can be found in the queue-4.7 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Miklos Szeredi <[email protected]>
Date: Sat, 1 Oct 2016 07:32:32 +0200
Subject: fuse: listxattr: verify xattr list

From: Miklos Szeredi <[email protected]>

commit cb3ae6d25a5471be62bfe6ac1fccc0e91edeaba0 upstream.

Make sure userspace filesystem is returning a well formed list of xattr names (zero or more nonzero length, null terminated strings).

[Michael Theall: only verify in the nonzero size case]

---
 fs/fuse/dir.c |   19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

@@ -1800,6 +1800,23 @@ static ssize_t fuse_getxattr(struct dent
 	return ret;
 }
 
+static int fuse_verify_xattr_list(char *list, size_t size)
+{
+	size_t origsize = size;
+
+	while (size) {
+		size_t thislen = strnlen(list, size);
+
+		if (!thislen || thislen == size)
+			return -EIO;
+
+		size -= thislen + 1;
+		list += thislen + 1;
+	}
+
+	return origsize;
+}
+
 static ssize_t fuse_listxattr(struct dentry *entry, char *list, size_t size)
 {
 	struct inode *inode = d_inode(entry);

@@ -1835,6 +1852,8 @@ static ssize_t fuse_listxattr(struct den
 	ret = fuse_simple_request(fc, &args);
 	if (!ret && !size)
 		ret = outarg.size;
+	if (ret > 0 && size)
+		ret = fuse_verify_xattr_list(list, ret);
 	if (ret == -ENOSYS) {
 		fc->no_listxattr = 1;
 		ret = -EOPNOTSUPP;

Patches currently in stable-queue which might be from [email protected] are

queue-4.7/fuse-listxattr-verify-xattr-list.patch queue-4.7/fuse-invalidate-dir-dentry-after-chmod.patch queue-4.7/fuse-fix-killing-sid-in-setattr.patch