Re: [PATCH 03/18] ovl: stack miscattr

2021-02-05 Thread Miklos Szeredi
On Fri, Feb 5, 2021 at 12:49 AM Vivek Goyal  wrote:

> > +int ovl_miscattr_set(struct dentry *dentry, struct miscattr *ma)
> > +{
> > + struct inode *inode = d_inode(dentry);
> > + struct dentry *upperdentry;
> > + const struct cred *old_cred;
> > + int err;
> > +
> > + err = ovl_want_write(dentry);
> > + if (err)
> > + goto out;
> > +
> > + err = ovl_copy_up(dentry);
> > + if (!err) {
> > + upperdentry = ovl_dentry_upper(dentry);
> > +
> > + old_cred = ovl_override_creds(inode->i_sb);
> > + /* err = security_file_ioctl(real.file, cmd, arg); */
>
> Is this an comment intended?

I don't remember, but I guess not.  Will fix and test.

Thanks,
Miklos


Re: [PATCH 03/18] ovl: stack miscattr

2021-02-05 Thread Miklos Szeredi
On Fri, Feb 5, 2021 at 4:25 PM Miklos Szeredi  wrote:
>
> On Fri, Feb 5, 2021 at 12:49 AM Vivek Goyal  wrote:
>
> > > +int ovl_miscattr_set(struct dentry *dentry, struct miscattr *ma)
> > > +{
> > > + struct inode *inode = d_inode(dentry);
> > > + struct dentry *upperdentry;
> > > + const struct cred *old_cred;
> > > + int err;
> > > +
> > > + err = ovl_want_write(dentry);
> > > + if (err)
> > > + goto out;
> > > +
> > > + err = ovl_copy_up(dentry);
> > > + if (!err) {
> > > + upperdentry = ovl_dentry_upper(dentry);
> > > +
> > > + old_cred = ovl_override_creds(inode->i_sb);
> > > + /* err = security_file_ioctl(real.file, cmd, arg); */
> >
> > Is this an comment intended?
>
> I don't remember, but I guess not.  Will fix and test.

Sorry, yes, problem is that there's no file pointer available at this point.

Fix is probably to introduce security_inode_miscattr_perm() hook.

Thanks,
Miklos


Re: [PATCH 03/18] ovl: stack miscattr

2021-02-04 Thread Vivek Goyal
On Wed, Feb 03, 2021 at 01:40:57PM +0100, Miklos Szeredi wrote:
> Add stacking for the miscattr operations.
> 
> Signed-off-by: Miklos Szeredi 
> ---
>  fs/overlayfs/dir.c   |  2 ++
>  fs/overlayfs/inode.c | 43 
>  fs/overlayfs/overlayfs.h |  2 ++
>  3 files changed, 47 insertions(+)
> 
> diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c
> index 28a075b5f5b2..77c6b44f8d83 100644
> --- a/fs/overlayfs/dir.c
> +++ b/fs/overlayfs/dir.c
> @@ -1300,4 +1300,6 @@ const struct inode_operations ovl_dir_inode_operations 
> = {
>   .listxattr  = ovl_listxattr,
>   .get_acl= ovl_get_acl,
>   .update_time= ovl_update_time,
> + .miscattr_get   = ovl_miscattr_get,
> + .miscattr_set   = ovl_miscattr_set,
>  };
> diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
> index d739e14c6814..97d36d1f28c3 100644
> --- a/fs/overlayfs/inode.c
> +++ b/fs/overlayfs/inode.c
> @@ -11,6 +11,7 @@
>  #include 
>  #include 
>  #include 
> +#include 
>  #include "overlayfs.h"
>  
>  
> @@ -495,6 +496,46 @@ static int ovl_fiemap(struct inode *inode, struct 
> fiemap_extent_info *fieinfo,
>   return err;
>  }
>  
> +int ovl_miscattr_set(struct dentry *dentry, struct miscattr *ma)
> +{
> + struct inode *inode = d_inode(dentry);
> + struct dentry *upperdentry;
> + const struct cred *old_cred;
> + int err;
> +
> + err = ovl_want_write(dentry);
> + if (err)
> + goto out;
> +
> + err = ovl_copy_up(dentry);
> + if (!err) {
> + upperdentry = ovl_dentry_upper(dentry);
> +
> + old_cred = ovl_override_creds(inode->i_sb);
> + /* err = security_file_ioctl(real.file, cmd, arg); */

Is this an comment intended?

Vivek

> + err = vfs_miscattr_set(upperdentry, ma);
> + revert_creds(old_cred);
> + ovl_copyflags(ovl_inode_real(inode), inode);
> + }
> + ovl_drop_write(dentry);
> +out:
> + return err;
> +}
> +
> +int ovl_miscattr_get(struct dentry *dentry, struct miscattr *ma)
> +{
> + struct inode *inode = d_inode(dentry);
> + struct dentry *realdentry = ovl_dentry_real(dentry);
> + const struct cred *old_cred;
> + int err;
> +
> + old_cred = ovl_override_creds(inode->i_sb);
> + err = vfs_miscattr_get(realdentry, ma);
> + revert_creds(old_cred);
> +
> + return err;
> +}
> +
>  static const struct inode_operations ovl_file_inode_operations = {
>   .setattr= ovl_setattr,
>   .permission = ovl_permission,
> @@ -503,6 +544,8 @@ static const struct inode_operations 
> ovl_file_inode_operations = {
>   .get_acl= ovl_get_acl,
>   .update_time= ovl_update_time,
>   .fiemap = ovl_fiemap,
> + .miscattr_get   = ovl_miscattr_get,
> + .miscattr_set   = ovl_miscattr_set,
>  };
>  
>  static const struct inode_operations ovl_symlink_inode_operations = {
> diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
> index b487e48c7fd4..d3ad02c34cca 100644
> --- a/fs/overlayfs/overlayfs.h
> +++ b/fs/overlayfs/overlayfs.h
> @@ -509,6 +509,8 @@ int __init ovl_aio_request_cache_init(void);
>  void ovl_aio_request_cache_destroy(void);
>  long ovl_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
>  long ovl_compat_ioctl(struct file *file, unsigned int cmd, unsigned long 
> arg);
> +int ovl_miscattr_get(struct dentry *dentry, struct miscattr *ma);
> +int ovl_miscattr_set(struct dentry *dentry, struct miscattr *ma);
>  
>  /* copy_up.c */
>  int ovl_copy_up(struct dentry *dentry);
> -- 
> 2.26.2
>