On Sun, Nov 21, 2021 at 03:54:55PM +0200, Leon Romanovsky wrote:
> On Thu, Nov 18, 2021 at 12:31:38PM -0800, Kees Cook wrote:
> > In preparation for FORTIFY_SOURCE performing compile-time and run-time
> > field bounds checking for memset(), avoid intentionally writing across
> > neighboring fields.
> >
> > Use memset_after() to zero the end of struct mlx5_ib_mr that should
> > be initialized.
> >
> > Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
> > drivers/infiniband/hw/mlx5/mlx5_ib.h | 5 ++---
> > 1 file changed, 2 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/infiniband/hw/mlx5/mlx5_ib.h b/drivers/infiniband/hw/mlx5/mlx5_ib.h
> > index e636e954f6bf..af94c9fe8753 100644
> > +++ b/drivers/infiniband/hw/mlx5/mlx5_ib.h
> > @@ -665,8 +665,7 @@ struct mlx5_ib_mr {
> > /* User MR data */
> > struct mlx5_cache_ent *cache_ent;
> > struct ib_umem *umem;
> > -
> > - /* This is zero'd when the MR is allocated */
> > + /* Everything after umem is zero'd when the MR is allocated */
> > union {
> > /* Used only while the MR is in the cache */
> > struct {
> > @@ -718,7 +717,7 @@ struct mlx5_ib_mr {
> > /* Zero the fields in the mr that are variant depending on usage */
> > static inline void mlx5_clear_mr(struct mlx5_ib_mr *mr)
> > {
> > - memset(mr->out, 0, sizeof(*mr) - offsetof(struct mlx5_ib_mr, out));
> > + memset_after(mr, 0, umem);
>
> I think that it is not equivalent change and you need "memset_after(mr, 0, cache_ent);"
> to clear umem pointer too.
Kees?
Jason
