Re: [PATCH] RDMA/uverbs: Reject WQ creation without a completion queue
From: Leon Romanovsky
Date: Tue Sep 15 2026 - 04:02:18 EST
On Mon, 07 Sep 2026 19:39:18 +0800, lirongqing wrote:
> UVERBS_ATTR_CREATE_WQ_CQ_HANDLE is declared UA_OPTIONAL in the ioctl
> method definition, so the mandatory attribute bitmap does not enforce
> its presence. When userspace omits it, uverbs_attr_get_obj() returns
> ERR_PTR(-ENOENT) and the handler stores that error pointer into
> wq_init_attr.cq without validation.
>
> The bogus cq pointer is then passed to the driver's create_wq callback.
> In the mlx5 case, create_rq() calls to_mcq(init_attr->cq) which applies
> container_of to the ERR_PTR value, producing a near-NULL pointer. The
> subsequent access in get_rq_ts_format() triggers a kernel NULL pointer
> dereference:
>
> [...]
Applied, thanks!
[1/1] RDMA/uverbs: Reject WQ creation without a completion queue
https://git.kernel.org/rdma/rdma/c/c55b7e155dd1f2
Best regards,
--
Leon Romanovsky <leon@xxxxxxxxxx>