On Fri, Jun 25, 2021 at 08:40:33AM -0400, Wang Shilong wrote:
> From: Wang Shilong <wshilong@xxxxxxx>
>
> U32_MAX is reserved for special purpose,
> qid_has_mapping() will return false if projid is
> 4294967295, dqget() will return NULL for it.
>
> So U32_MAX is unsupported Project ID, fix to forbid
> it.
Actually, it's INVALID_PROJID, not U32_MAX, and we already have a
check function for that:
static inline bool projid_valid(kprojid_t projid)
{
return !projid_eq(projid, INVALID_PROJID);
}
> Signed-off-by: Wang Shilong <wshilong@xxxxxxx>
> ---
> fs/ext4/ioctl.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
> index 31627f7dc5cd..f3a8d962c291 100644
> --- a/fs/ext4/ioctl.c
> +++ b/fs/ext4/ioctl.c
> @@ -744,6 +744,9 @@ int ext4_fileattr_set(struct user_namespace *mnt_userns,
> u32 flags = fa->flags;
> int err = -EOPNOTSUPP;
>
> + if (fa->fsx_projid >= U32_MAX)
> + return -EINVAL;
> +
This should actually be calling qid_valid() or projid_valid(),
and it should be in generic code because multiple filesystems
support project quotas. i.e this should be checked in
fileattr_set_prepare(), not in ext4 specific code.
Cheers,
Dave.
--
Dave Chinner
david@xxxxxxxxxxxxx
