RDMA/nldev: Don't expose unsafe global rkey to regular user

Unsafe global rkey is considered dangerous because it exposes memory
registered for all memory in the system. Only users with a QP on the same
PD can use the rkey, and generally those QPs will already know the
value. However, out of caution, do not expose the value to unprivleged
users on the local system. Require CAP_NET_ADMIN instead.

Cc: <stable@vger.kernel.org> # 4.16
Fixes: 29cf1351d450 ("RDMA/nldev: provide detailed PD information")
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

diff --git a/drivers/infiniband/core/nldev.c b/drivers/infiniband/core/nldev.c
index e600fc23ae62fc2e09f85aa5f5dc3a504875473b..3c97a8b6bf1e0f881671cdc70895624050b265c1 100644 (file)
--- a/drivers/infiniband/core/nldev.c
+++ b/drivers/infiniband/core/nldev.c
@@ -584,10 +584,6 @@ static int fill_res_pd_entry(struct sk_buff *msg, struct netlink_callback *cb,
        if (nla_put_u64_64bit(msg, RDMA_NLDEV_ATTR_RES_USECNT,
                              atomic_read(&pd->usecnt), RDMA_NLDEV_ATTR_PAD))
                goto err;
-       if ((pd->flags & IB_PD_UNSAFE_GLOBAL_RKEY) &&
-           nla_put_u32(msg, RDMA_NLDEV_ATTR_RES_UNSAFE_GLOBAL_RKEY,
-                       pd->unsafe_global_rkey))
-               goto err;
 
        if (fill_res_name_pid(msg, res))
                goto err;