IB/mlx5: Fix integer overflows in mlx5_ib_create_srq

This patch validates user provided input to prevent integer overflow due
to integer manipulation in the mlx5_ib_create_srq function.

Cc: syzkaller <syzkaller@googlegroups.com>
Fixes: e126ba9 ("mlx5: Add driver for Mellanox Connect-IB adapters")
Signed-off-by: Boris Pismenny <borisp@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>

Author: Boris Pismenny

drivers/infiniband/hw/mlx5/srq.c

@@ -241,8 +241,8 @@ struct ib_srq *mlx5_ib_create_srq(struct ib_pd *pd,
 {
 	struct mlx5_ib_dev *dev = to_mdev(pd->device);
 	struct mlx5_ib_srq *srq;
-	int desc_size;
-	int buf_size;
+	size_t desc_size;
+	size_t buf_size;
 	int err;
 	struct mlx5_srq_attr in = {0};
 	__u32 max_srq_wqes = 1 << MLX5_CAP_GEN(dev->mdev, log_max_srq_sz);
@@ -266,15 +266,18 @@ struct ib_srq *mlx5_ib_create_srq(struct ib_pd *pd,
 
 	desc_size = sizeof(struct mlx5_wqe_srq_next_seg) +
 		    srq->msrq.max_gs * sizeof(struct mlx5_wqe_data_seg);
+	if (desc_size == 0 || srq->msrq.max_gs > desc_size)
+		return ERR_PTR(-EINVAL);
 	desc_size = roundup_pow_of_two(desc_size);
-	desc_size = max_t(int, 32, desc_size);
+	desc_size = max_t(size_t, 32, desc_size);
+	if (desc_size < sizeof(struct mlx5_wqe_srq_next_seg))
+		return ERR_PTR(-EINVAL);
 	srq->msrq.max_avail_gather = (desc_size - sizeof(struct mlx5_wqe_srq_next_seg)) /
 		sizeof(struct mlx5_wqe_data_seg);
 	srq->msrq.wqe_shift = ilog2(desc_size);
 	buf_size = srq->msrq.max * desc_size;
-	mlx5_ib_dbg(dev, "desc_size 0x%x, req wr 0x%x, srq size 0x%x, max_gs 0x%x, max_avail_gather 0x%x\n",
-		    desc_size, init_attr->attr.max_wr, srq->msrq.max, srq->msrq.max_gs,
-		    srq->msrq.max_avail_gather);
+	if (buf_size < desc_size)
+		return ERR_PTR(-EINVAL);
 	in.type = init_attr->srq_type;
 
 	if (pd->uobject)

include/linux/mlx5/driver.h

@@ -453,8 +453,8 @@ struct mlx5_core_srq {
 	struct mlx5_core_rsc_common	common; /* must be first */
 	u32		srqn;
 	int		max;
-	int		max_gs;
-	int		max_avail_gather;
+	size_t		max_gs;
+	size_t		max_avail_gather;
 	int		wqe_shift;
 	void (*event)	(struct mlx5_core_srq *, enum mlx5_event);