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>
---
v2: rebased, umem moved into the union and is expected to be wiped
https://lore.kernel.org/lkml/20211207194525.GL6385@xxxxxxxxxx
---
drivers/infiniband/hw/mlx5/mlx5_ib.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/infiniband/hw/mlx5/mlx5_ib.h b/drivers/infiniband/hw/mlx5/mlx5_ib.h
index 4a7a56ed740b..ded10719b643 100644
--- a/drivers/infiniband/hw/mlx5/mlx5_ib.h
+++ b/drivers/infiniband/hw/mlx5/mlx5_ib.h
@@ -664,8 +664,8 @@ struct mlx5_ib_mr {
/* User MR data */
struct mlx5_cache_ent *cache_ent;
+ /* Everything after cache_ent is zero'd when MR allocated */
- /* This is zero'd when the MR is allocated */
union {
/* Used only while the MR is in the cache */
struct {
@@ -718,7 +718,7 @@ 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, cache_ent);
}
static inline bool is_odp_mr(struct mlx5_ib_mr *mr)
--
2.30.2
