Re: [Qemu-devel] [PATCH v1 3/6] pvrdma: check number of pages when creating rings

[Yuval Shaia]

On Wed, Dec 12, 2018 at 05:17:23PM +0530, P J P wrote:
> From: Prasad J Pandit <address@hidden>
> 
> When creating CQ/QP rings, an object can have up to
> PVRDMA_MAX_FAST_REG_PAGES=128 pages. Check 'npages' parameter
> to avoid excessive memory allocation or a null dereference.
> 
> Reported-by: Li Qiang <address@hidden>
> Signed-off-by: Prasad J Pandit <address@hidden>
> ---
>  hw/rdma/vmw/pvrdma_cmd.c | 11 +++++++++++
>  1 file changed, 11 insertions(+)
> 
> Update v1: move check before page dir/tbl map
>   -> https://lists.gnu.org/archive/html/qemu-devel/2018-12/msg02257.html
> 
> diff --git a/hw/rdma/vmw/pvrdma_cmd.c b/hw/rdma/vmw/pvrdma_cmd.c
> index 4f616d4177..e37fb18280 100644
> --- a/hw/rdma/vmw/pvrdma_cmd.c
> +++ b/hw/rdma/vmw/pvrdma_cmd.c
> @@ -259,6 +259,11 @@ static int create_cq_ring(PCIDevice *pci_dev , 
> PvrdmaRing **ring,
>      int rc = -EINVAL;
>      char ring_name[MAX_RING_NAME_SZ];
>  
> +    if (!nchunks || nchunks > PVRDMA_MAX_FAST_REG_PAGES) {
> +        pr_dbg("invalid nchunks: %d\n", nchunks);
> +        return rc;
> +    }
> +
>      pr_dbg("pdir_dma=0x%llx\n", (long long unsigned int)pdir_dma);
>      dir = rdma_pci_dma_map(pci_dev, pdir_dma, TARGET_PAGE_SIZE);
>      if (!dir) {
> @@ -371,6 +376,12 @@ static int create_qp_rings(PCIDevice *pci_dev, uint64_t 
> pdir_dma,
>      char ring_name[MAX_RING_NAME_SZ];
>      uint32_t wqe_sz;
>  
> +    if (!spages || spages > PVRDMA_MAX_FAST_REG_PAGES
> +        || !rpages || rpages > PVRDMA_MAX_FAST_REG_PAGES) {
> +        pr_dbg("invalid pages: %d, %d\n", spages, rpages);
> +        return rc;
> +    }
> +
>      pr_dbg("pdir_dma=0x%llx\n", (long long unsigned int)pdir_dma);
>      dir = rdma_pci_dma_map(pci_dev, pdir_dma, TARGET_PAGE_SIZE);
>      if (!dir) {

Thanks.

Reviewed-by: Yuval Shaia <address@hidden>

> -- 
> 2.19.2
>