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* [PATCH] RDMA/mlx5: Use memset_after() to zero struct mlx5_ib_mr
@ 2021-11-18 20:31 Kees Cook
  2021-11-21 13:54 ` Leon Romanovsky
  0 siblings, 1 reply; 7+ messages in thread
From: Kees Cook @ 2021-11-18 20:31 UTC (permalink / raw)
  To: Leon Romanovsky
  Cc: Kees Cook, Doug Ledford, Jason Gunthorpe, linux-kernel,
	linux-rdma, linux-hardening

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@chromium.org>
---
 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
--- a/drivers/infiniband/hw/mlx5/mlx5_ib.h
+++ 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);
 }
 
 static inline bool is_odp_mr(struct mlx5_ib_mr *mr)
-- 
2.30.2


^ permalink raw reply related	[flat|nested] 7+ messages in thread

end of thread, other threads:[~2022-01-13  0:32 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2021-11-18 20:31 [PATCH] RDMA/mlx5: Use memset_after() to zero struct mlx5_ib_mr Kees Cook
2021-11-21 13:54 ` Leon Romanovsky
2021-12-07 18:47   ` Jason Gunthorpe
2021-12-07 19:41     ` Kees Cook
2021-12-07 19:45       ` Jason Gunthorpe
2022-01-12 20:49         ` Kees Cook
2022-01-13  0:32           ` Jason Gunthorpe

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