On 28.11.18 г. 5:07 ч., Lu Fengqi wrote:
> The generic/513 tell that cloning into a file did not strip security
> privileges (suid, capabilities) like a regular write would.
>
> Signed-off-by: Lu Fengqi <lufq.fnst@xxxxxxxxxxxxxx>
> ---
> The xfs and ocfs2 call generic_remap_file_range_prep to drop file
> privileges, I'm not sure whether btrfs should do the same thing.
Why do you think btrfs shouldn't do the same thing. Looking at
remap_file_range_prep it seems that btrfs is missing a ton of checks
that are useful i.e immutable files/aligned offsets etc.
>
> Any suggestion?
>
> fs/btrfs/ioctl.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
> index 410c7e007ba8..bc33c480603b 100644
> --- a/fs/btrfs/ioctl.c
> +++ b/fs/btrfs/ioctl.c
> @@ -4312,6 +4312,10 @@ static noinline int btrfs_clone_files(struct file *file, struct file *file_src,
> goto out_unlock;
> }
>
> + ret = file_remove_privs(file);
> + if (ret)
> + goto out_unlock;
> +
> if (destoff > inode->i_size) {
> ret = btrfs_cont_expand(inode, inode->i_size, destoff);
> if (ret)
>
