bpf: reject invalid names right in ->lookup()
... and other methods won't see them at all
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/kernel/bpf/inode.c b/kernel/bpf/inode.c
index f2ece3c..35d21c1 100644
--- a/kernel/bpf/inode.c
+++ b/kernel/bpf/inode.c
@@ -119,18 +119,10 @@
return 0;
}
-static bool bpf_dname_reserved(const struct dentry *dentry)
-{
- return strchr(dentry->d_name.name, '.');
-}
-
static int bpf_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
{
struct inode *inode;
- if (bpf_dname_reserved(dentry))
- return -EPERM;
-
inode = bpf_get_inode(dir->i_sb, dir, mode | S_IFDIR);
if (IS_ERR(inode))
return PTR_ERR(inode);
@@ -152,9 +144,6 @@
{
struct inode *inode;
- if (bpf_dname_reserved(dentry))
- return -EPERM;
-
inode = bpf_get_inode(dir->i_sb, dir, mode | S_IFREG);
if (IS_ERR(inode))
return PTR_ERR(inode);
@@ -187,31 +176,21 @@
}
}
-static int bpf_link(struct dentry *old_dentry, struct inode *dir,
- struct dentry *new_dentry)
+static struct dentry *
+bpf_lookup(struct inode *dir, struct dentry *dentry, unsigned flags)
{
- if (bpf_dname_reserved(new_dentry))
- return -EPERM;
-
- return simple_link(old_dentry, dir, new_dentry);
-}
-
-static int bpf_rename(struct inode *old_dir, struct dentry *old_dentry,
- struct inode *new_dir, struct dentry *new_dentry)
-{
- if (bpf_dname_reserved(new_dentry))
- return -EPERM;
-
- return simple_rename(old_dir, old_dentry, new_dir, new_dentry);
+ if (strchr(dentry->d_name.name, '.'))
+ return ERR_PTR(-EPERM);
+ return simple_lookup(dir, dentry, flags);
}
static const struct inode_operations bpf_dir_iops = {
- .lookup = simple_lookup,
+ .lookup = bpf_lookup,
.mknod = bpf_mkobj,
.mkdir = bpf_mkdir,
.rmdir = simple_rmdir,
- .rename = bpf_rename,
- .link = bpf_link,
+ .rename = simple_rename,
+ .link = simple_link,
.unlink = simple_unlink,
};