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

commit a9666c1cae8dbcd1a9aacd08a778bf2a28eea300 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/infiniband/core/nldev.c b/drivers/infiniband/core/nldev.c
index 0385ab4383208b40a692f60cced8429d8486b528..f6fa9b115fdad9fe7e6430d1a0642edfd07049d1 100644 (file)
--- a/drivers/infiniband/core/nldev.c
+++ b/drivers/infiniband/core/nldev.c
@@ -579,10 +579,6 @@ 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;