On 09/11, Wang Shilong wrote:
> From: Wang Shilong <wangshilong1991@xxxxxxxxx>
>
> Currently, project quota could be changed by fssetxattr
> ioctl, and existed permission check inode_owner_or_capable()
> is obviously not enough, just think that common users could
> change project id of file, that could make users to
> break project quota easily.
>
> This patch try to follow same regular of xfs project
> quota:
>
> "Project Quota ID state is only allowed to change from
> within the init namespace. Enforce that restriction only
> if we are trying to change the quota ID state.
> Everything else is allowed in user namespaces."
>
> Besides that, check and set project id'state should
> be an atomic operation, protect whole operation with
> inode lock.
>
> Signed-off-by: Wang Shilong <wshilong@xxxxxxx>
> ---
> v2->v3: remove inode_lock() and mnt_want_write_file()
> inside f2fs_ioc_setproject()
> v1->v2: rename f2fs_ioctl_setattr_check_projid()
> to f2fs_ioctl_check_project()
> fs/f2fs/file.c | 61 ++++++++++++++++++++++++++++++++++++----------------------
> 1 file changed, 38 insertions(+), 23 deletions(-)
>
> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
> index 5474aaa..f5170e6 100644
> --- a/fs/f2fs/file.c
> +++ b/fs/f2fs/file.c
> @@ -2617,34 +2617,26 @@ static int f2fs_ioc_setproject(struct file *filp, __u32 projid)
> if (projid_eq(kprojid, F2FS_I(inode)->i_projid))
> return 0;
>
> - err = mnt_want_write_file(filp);
> - if (err)
> - return err;
> -
> err = -EPERM;
> - inode_lock(inode);
> -
> /* Is it quota file? Do not allow user to mess with it */
> if (IS_NOQUOTA(inode))
> - goto out_unlock;
> + return err;
>
> ipage = f2fs_get_node_page(sbi, inode->i_ino);
> - if (IS_ERR(ipage)) {
> - err = PTR_ERR(ipage);
> - goto out_unlock;
> - }
> + if (IS_ERR(ipage))
> + return PTR_ERR(ipage);
>
> if (!F2FS_FITS_IN_INODE(F2FS_INODE(ipage), fi->i_extra_isize,
> i_projid)) {
> err = -EOVERFLOW;
> f2fs_put_page(ipage, 1);
> - goto out_unlock;
> + return err;
> }
> f2fs_put_page(ipage, 1);
>
> err = dquot_initialize(inode);
> if (err)
> - goto out_unlock;
> + return err;
>
> transfer_to[PRJQUOTA] = dqget(sb, make_kqid_projid(kprojid));
> if (!IS_ERR(transfer_to[PRJQUOTA])) {
> @@ -2658,9 +2650,6 @@ static int f2fs_ioc_setproject(struct file *filp, __u32 projid)
> inode->i_ctime = current_time(inode);
> out_dirty:
> f2fs_mark_inode_dirty_sync(inode, true);
> -out_unlock:
> - inode_unlock(inode);
> - mnt_drop_write_file(filp);
> return err;
> }
> #else
> @@ -2736,6 +2725,31 @@ static int f2fs_ioc_fsgetxattr(struct file *filp, unsigned long arg)
> return 0;
> }
>
> +static int
> +f2fs_ioctl_check_project(struct inode *inode, struct fsxattr *fa)
We're not following this coding style. Let me allow to declare like this.
static int f2fs_ioctl_...
Thanks,
> +{
> + /*
> + * Project Quota ID state is only allowed to change from within the init
> + * namespace. Enforce that restriction only if we are trying to change
> + * the quota ID state. Everything else is allowed in user namespaces.
> + */
> + if (current_user_ns() == &init_user_ns)
> + return 0;
> +
> + if (__kprojid_val(F2FS_I(inode)->i_projid) != fa->fsx_projid)
> + return -EINVAL;
> +
> + if (F2FS_I(inode)->i_flags & F2FS_PROJINHERIT_FL) {
> + if (!(fa->fsx_xflags & FS_XFLAG_PROJINHERIT))
> + return -EINVAL;
> + } else {
> + if (fa->fsx_xflags & FS_XFLAG_PROJINHERIT)
> + return -EINVAL;
> + }
> +
> + return 0;
> +}
> +
> static int f2fs_ioc_fssetxattr(struct file *filp, unsigned long arg)
> {
> struct inode *inode = file_inode(filp);
> @@ -2763,19 +2777,20 @@ static int f2fs_ioc_fssetxattr(struct file *filp, unsigned long arg)
> return err;
>
> inode_lock(inode);
> + err = f2fs_ioctl_check_project(inode, &fa);
> + if (err)
> + goto out;
> flags = (fi->i_flags & ~F2FS_FL_XFLAG_VISIBLE) |
> (flags & F2FS_FL_XFLAG_VISIBLE);
> err = __f2fs_ioc_setflags(inode, flags);
> - inode_unlock(inode);
> - mnt_drop_write_file(filp);
> if (err)
> - return err;
> + goto out;
>
> err = f2fs_ioc_setproject(filp, fa.fsx_projid);
> - if (err)
> - return err;
> -
> - return 0;
> +out:
> + inode_unlock(inode);
> + mnt_drop_write_file(filp);
> + return err;
> }
>
> int f2fs_pin_file_control(struct inode *inode, bool inc)
> --
> 1.8.3.1
>
>
>
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