Re: [PATCH] btrfs-progs: common: make sure that qgroup id is in range

[Sidong Yang <realwakka@gmail.com>]

On Tue, Mar 16, 2021 at 01:44:33PM +0800, Qu Wenruo wrote:
> 
> 
> On 2021/3/15 下午11:56, Sidong Yang wrote:
> > When user assign qgroup with qgroup id that is too big to exceeds
> > range and invade level value, and it works without any error. but
> > this action would be make undefined error. this code make sure that
> > qgroup id doesn't exceed range(0 ~ 2^48-1).
> > 
> > Signed-off-by: Sidong Yang <realwakka@gmail.com>
> 
> Shouldn't the check also happen inside the ioctl?

Yes, I checked the ioctl code in kernel. but there is only the code that
check if it is zero like !sa->qgroupid. and it just assign to
key.offset. Also it should be checked in ioctl?

> 
> Thanks,
> Qu
> > ---
> >   common/utils.c | 5 +++++
> >   1 file changed, 5 insertions(+)
> > 
> > diff --git a/common/utils.c b/common/utils.c
> > index 57e41432..a2f72550 100644
> > --- a/common/utils.c
> > +++ b/common/utils.c
> > @@ -727,6 +727,8 @@ u64 parse_qgroupid(const char *p)
> >   		id = strtoull(p, &ptr_parse_end, 10);
> >   		if (ptr_parse_end != ptr_src_end)
> >   			goto path;
> > +		if (id >> BTRFS_QGROUP_LEVEL_SHIFT)
> > +			goto err;
> >   		return id;
> >   	}
> >   	level = strtoull(p, &ptr_parse_end, 10);
> > @@ -734,6 +736,9 @@ u64 parse_qgroupid(const char *p)
> >   		goto path;
> > 
> >   	id = strtoull(s + 1, &ptr_parse_end, 10);
> > +	if (id >> BTRFS_QGROUP_LEVEL_SHIFT)
> > +		goto err;
> > +
> >   	if (ptr_parse_end != ptr_src_end)
> >   		goto  path;
> > 
> >