Commit 236bfd8e authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs 

Pull overlayfs fixes from Miklos Szeredi:
 "This contains fixes for a dentry leak, a regression in 4.6 noticed by
  Docker users and missing write access checking in truncate"

* 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
  ovl: warn instead of error if d_type is not supported
  ovl: get_write_access() in truncate
  ovl: fix dentry leak for default_permissions
parents 4f302921 e7c0b599

fs/overlayfs/inode.c

+26 −3
Original line number Diff line number Diff line
@@ -59,16 +59,37 @@ int ovl_setattr(struct dentry *dentry, struct iattr *attr) 
	if (err)

		goto out;



	if (attr->ia_valid & ATTR_SIZE) {

		struct inode *realinode = d_inode(ovl_dentry_real(dentry));



		err = -ETXTBSY;

		if (atomic_read(&realinode->i_writecount) < 0)

			goto out_drop_write;

	}



	err = ovl_copy_up(dentry);

	if (!err) {

		struct inode *winode = NULL;



		upperdentry = ovl_dentry_upper(dentry);



		if (attr->ia_valid & ATTR_SIZE) {

			winode = d_inode(upperdentry);

			err = get_write_access(winode);

			if (err)

				goto out_drop_write;

		}



		inode_lock(upperdentry->d_inode);

		err = notify_change(upperdentry, attr, NULL);

		if (!err)

			ovl_copyattr(upperdentry->d_inode, dentry->d_inode);

		inode_unlock(upperdentry->d_inode);



		if (winode)

			put_write_access(winode);

	}

out_drop_write:

	ovl_drop_write(dentry);

out:

	return err;
@@ -121,16 +142,18 @@ int ovl_permission(struct inode *inode, int mask) 


		err = vfs_getattr(&realpath, &stat);

		if (err)

			return err;

			goto out_dput;



		err = -ESTALE;

		if ((stat.mode ^ inode->i_mode) & S_IFMT)

			return -ESTALE;

			goto out_dput;



		inode->i_mode = stat.mode;

		inode->i_uid = stat.uid;

		inode->i_gid = stat.gid;



		return generic_permission(inode, mask);

		err = generic_permission(inode, mask);

		goto out_dput;

	}



	/* Careful in RCU walk mode */

fs/overlayfs/super.c

+7 −5
Original line number Diff line number Diff line
@@ -1082,11 +1082,13 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) 
			if (err < 0)

				goto out_put_workdir;



			if (!err) {

				pr_err("overlayfs: upper fs needs to support d_type.\n");

				err = -EINVAL;

				goto out_put_workdir;

			}

			/*

			 * We allowed this configuration and don't want to

			 * break users over kernel upgrade. So warn instead

			 * of erroring out.

			 */

			if (!err)

				pr_warn("overlayfs: upper fs needs to support d_type.\n");

		}

	}

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