In preparation for making the kmalloc family of allocators type aware,
we need to make sure that the returned type from the allocation matches
the type of the variable being assigned. (Before, the allocator would
always return "void *", which can be implicitly cast to any pointer type.)

The assigned type is "unsigned long **", but the returned type will be
"long **". These are the same allocation size (pointer size), but the
types do not match. Adjust the allocation type to match the assignment.

Signed-off-by: Kees Cook <kees@kernel.org>
---
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: <linux-rdma@vger.kernel.org>
---
 drivers/infiniband/hw/mthca/mthca_mr.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/infiniband/hw/mthca/mthca_mr.c b/drivers/infiniband/hw/mthca/mthca_mr.c
index 192f83fd7c8a..dacb8ceeebe0 100644
--- a/drivers/infiniband/hw/mthca/mthca_mr.c
+++ b/drivers/infiniband/hw/mthca/mthca_mr.c
@@ -144,7 +144,7 @@ static int mthca_buddy_init(struct mthca_buddy *buddy, int max_order)
 	buddy->max_order = max_order;
 	spin_lock_init(&buddy->lock);
 
-	buddy->bits = kcalloc(buddy->max_order + 1, sizeof(long *),
+	buddy->bits = kcalloc(buddy->max_order + 1, sizeof(*buddy->bits),
 			      GFP_KERNEL);
 	buddy->num_free = kcalloc((buddy->max_order + 1), sizeof *buddy->num_free,
 				  GFP_KERNEL);
-- 
2.34.1

On Fri, 25 Apr 2025 23:12:09 -0700, Kees Cook wrote:
> In preparation for making the kmalloc family of allocators type aware,
> we need to make sure that the returned type from the allocation matches
> the type of the variable being assigned. (Before, the allocator would
> always return "void *", which can be implicitly cast to any pointer type.)
> 
> The assigned type is "unsigned long **", but the returned type will be
> "long **". These are the same allocation size (pointer size), but the
> types do not match. Adjust the allocation type to match the assignment.
> 
> [...]

Applied, thanks!

[1/1] IB/mthca: Adjust buddy->bits allocation type
      https://git.kernel.org/rdma/rdma/c/7c04bc97171780

Best regards,
-- 
Leon Romanovsky <leon@kernel.org>