RDMA/mthca: Use correct sizing on buffers holding page DMA addresses

The buffer that holds the page DMA addresses is sized off umem->nmap.
This can potentially cause out of bound accesses on the PBL array when
iterating the umem DMA-mapped SGL. This is because if umem pages are
combined, umem->nmap can be much lower than the number of system pages
in umem.

Use ib_umem_num_pages() to size this buffer.

Signed-off-by: Shiraz Saleem <shiraz.saleem@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

diff --git a/drivers/infiniband/hw/mthca/mthca_provider.c b/drivers/infiniband/hw/mthca/mthca_provider.c
index d063d7a..35c3119 100644 (file)
--- a/drivers/infiniband/hw/mthca/mthca_provider.c
+++ b/drivers/infiniband/hw/mthca/mthca_provider.c
@@ -914,7 +914,7 @@ static struct ib_mr *mthca_reg_user_mr(struct ib_pd *pd, u64 start, u64 length,
                goto err;
        }
 
-       n = mr->umem->nmap;
+       n = ib_umem_num_pages(mr->umem);
 
        mr->mtt = mthca_alloc_mtt(dev, n);
        if (IS_ERR(mr->mtt)) {