Commit f007d5c9 authored by Miklos Szeredi's avatar Miklos Szeredi Committed by Linus Torvalds

[PATCH] fuse: check directory aliasing in mkdir

Check the created directory inode for aliases in the mkdir() method.
Signed-off-by: default avatarMiklos Szeredi <miklos@szeredi.hu>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent ea164d73
...@@ -74,6 +74,19 @@ static int fuse_dentry_revalidate(struct dentry *entry, struct nameidata *nd) ...@@ -74,6 +74,19 @@ static int fuse_dentry_revalidate(struct dentry *entry, struct nameidata *nd)
return 1; 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 struct dentry_operations fuse_dentry_operations = { static struct dentry_operations fuse_dentry_operations = {
.d_revalidate = fuse_dentry_revalidate, .d_revalidate = fuse_dentry_revalidate,
}; };
...@@ -263,7 +276,7 @@ static int create_new_entry(struct fuse_conn *fc, struct fuse_req *req, ...@@ -263,7 +276,7 @@ static int create_new_entry(struct fuse_conn *fc, struct fuse_req *req,
fuse_put_request(fc, req); fuse_put_request(fc, req);
/* Don't allow userspace to do really stupid things... */ /* 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); iput(inode);
return -EIO; return -EIO;
} }
...@@ -874,15 +887,10 @@ static struct dentry *fuse_lookup(struct inode *dir, struct dentry *entry, ...@@ -874,15 +887,10 @@ static struct dentry *fuse_lookup(struct inode *dir, struct dentry *entry,
err = fuse_lookup_iget(dir, entry, &inode); err = fuse_lookup_iget(dir, entry, &inode);
if (err) if (err)
return ERR_PTR(err); return ERR_PTR(err);
if (inode && S_ISDIR(inode->i_mode)) { if (inode && dir_alias(inode)) {
/* Don't allow creating an alias to a directory */
struct dentry *alias = d_find_alias(inode);
if (alias) {
dput(alias);
iput(inode); iput(inode);
return ERR_PTR(-EIO); return ERR_PTR(-EIO);
} }
}
d_add(entry, inode); d_add(entry, inode);
return NULL; return NULL;
} }
......
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