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-rw-r--r--fs/fuse/dir.c37
1 files changed, 25 insertions, 12 deletions
diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index c045cc70c749..51f5da652771 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -74,6 +74,24 @@ static int fuse_dentry_revalidate(struct dentry *entry, struct nameidata *nd)
return 1;
}
+static int dir_alias(struct inode *inode)
+{
+ if (S_ISDIR(inode->i_mode)) {
+ /* Don't allow creating an alias to a directory */
+ struct dentry *alias = d_find_alias(inode);
+ if (alias) {
+ dput(alias);
+ return 1;
+ }
+ }
+ return 0;
+}
+
+static inline int invalid_nodeid(u64 nodeid)
+{
+ return !nodeid || nodeid == FUSE_ROOT_ID;
+}
+
static struct dentry_operations fuse_dentry_operations = {
.d_revalidate = fuse_dentry_revalidate,
};
@@ -97,7 +115,7 @@ static int fuse_lookup_iget(struct inode *dir, struct dentry *entry,
fuse_lookup_init(req, dir, entry, &outarg);
request_send(fc, req);
err = req->out.h.error;
- if (!err && (!outarg.nodeid || outarg.nodeid == FUSE_ROOT_ID))
+ if (!err && invalid_nodeid(outarg.nodeid))
err = -EIO;
if (!err) {
inode = fuse_iget(dir->i_sb, outarg.nodeid, outarg.generation,
@@ -193,7 +211,7 @@ static int fuse_create_open(struct inode *dir, struct dentry *entry, int mode,
}
err = -EIO;
- if (!S_ISREG(outentry.attr.mode))
+ if (!S_ISREG(outentry.attr.mode) || invalid_nodeid(outentry.nodeid))
goto out_free_ff;
inode = fuse_iget(dir->i_sb, outentry.nodeid, outentry.generation,
@@ -250,7 +268,7 @@ static int create_new_entry(struct fuse_conn *fc, struct fuse_req *req,
fuse_put_request(fc, req);
return err;
}
- if (!outarg.nodeid || outarg.nodeid == FUSE_ROOT_ID) {
+ if (invalid_nodeid(outarg.nodeid)) {
fuse_put_request(fc, req);
return -EIO;
}
@@ -263,7 +281,7 @@ static int create_new_entry(struct fuse_conn *fc, struct fuse_req *req,
fuse_put_request(fc, req);
/* Don't allow userspace to do really stupid things... */
- if ((inode->i_mode ^ mode) & S_IFMT) {
+ if (((inode->i_mode ^ mode) & S_IFMT) || dir_alias(inode)) {
iput(inode);
return -EIO;
}
@@ -874,14 +892,9 @@ static struct dentry *fuse_lookup(struct inode *dir, struct dentry *entry,
err = fuse_lookup_iget(dir, entry, &inode);
if (err)
return ERR_PTR(err);
- if (inode && S_ISDIR(inode->i_mode)) {
- /* Don't allow creating an alias to a directory */
- struct dentry *alias = d_find_alias(inode);
- if (alias) {
- dput(alias);
- iput(inode);
- return ERR_PTR(-EIO);
- }
+ if (inode && dir_alias(inode)) {
+ iput(inode);
+ return ERR_PTR(-EIO);
}
d_add(entry, inode);
return NULL;