[PATCH] fuse: check file type in lookup
Previously invalid types were quietly changed to regular files, but at
revalidation the inode was changed to bad. This was rather inconsistent
behavior.
Now check if the type is valid on initial lookup, and return -EIO if not.
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index f156392..417bcee 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -166,6 +166,12 @@
.d_revalidate = fuse_dentry_revalidate,
};
+static inline int valid_mode(int m)
+{
+ return S_ISREG(m) || S_ISDIR(m) || S_ISLNK(m) || S_ISCHR(m) ||
+ S_ISBLK(m) || S_ISFIFO(m) || S_ISSOCK(m);
+}
+
static struct dentry *fuse_lookup(struct inode *dir, struct dentry *entry,
struct nameidata *nd)
{
@@ -185,7 +191,8 @@
fuse_lookup_init(req, dir, entry, &outarg);
request_send(fc, req);
err = req->out.h.error;
- if (!err && outarg.nodeid && invalid_nodeid(outarg.nodeid))
+ if (!err && ((outarg.nodeid && invalid_nodeid(outarg.nodeid)) ||
+ !valid_mode(outarg.attr.mode)))
err = -EIO;
if (!err && outarg.nodeid) {
inode = fuse_iget(dir->i_sb, outarg.nodeid, outarg.generation,
@@ -328,10 +335,13 @@
fuse_put_request(fc, req);
return err;
}
- if (invalid_nodeid(outarg.nodeid)) {
- fuse_put_request(fc, req);
- return -EIO;
- }
+ err = -EIO;
+ if (invalid_nodeid(outarg.nodeid))
+ goto out_put_request;
+
+ if ((outarg.attr.mode ^ mode) & S_IFMT)
+ goto out_put_request;
+
inode = fuse_iget(dir->i_sb, outarg.nodeid, outarg.generation,
&outarg.attr);
if (!inode) {
@@ -340,8 +350,7 @@
}
fuse_put_request(fc, req);
- /* Don't allow userspace to do really stupid things... */
- if (((inode->i_mode ^ mode) & S_IFMT) || dir_alias(inode)) {
+ if (dir_alias(inode)) {
iput(inode);
return -EIO;
}
@@ -350,6 +359,10 @@
fuse_change_timeout(entry, &outarg);
fuse_invalidate_attr(dir);
return 0;
+
+ out_put_request:
+ fuse_put_request(fc, req);
+ return err;
}
static int fuse_mknod(struct inode *dir, struct dentry *entry, int mode,