On Tue, May 09, 2017 at 02:31:21PM +0100, Colin King wrote:
> diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
> index 1dbf62190bee..c453a1998e00 100644
> --- a/fs/nfsd/nfs4proc.c
> +++ b/fs/nfsd/nfs4proc.c
> @@ -1259,7 +1259,8 @@ nfsd4_layout_verify(struct svc_export *exp, unsigned
> int layout_type)
> return NULL;
> }
>
> - if (layout_type >= 32 || !(exp->ex_layout_types & (1 << layout_type))) {
> + if (layout_type >= LAYOUT_TYPE_MAX ||
> + !(exp->ex_layout_types & (1 << layout_type))) {
The 32 is there to prevent a shift wrapping bug. The bit test prevents
a buffer overflow so this can't actually overflow. But this change
doesn't hurt and is probably cleaner.
exp->ex_layout_types is set in nfsd4_setup_layout_type().
regards,
dan carpenter
