[PATCH] RDMA/ucma: fix a kernel-infoleak in ucma_init_qp_attr()

[Dan Carpenter <dan.carpenter@oracle.com>]

From: Haimin Zhang <tcs.kernel@gmail.com>

The ib_copy_ah_attr_to_user() function only initializes "resp.grh" if
the "resp.is_global" flag is set.  Unfortunately, this data is copied to
the user and copying uninitialized stack data to the user is an
information leak.  Zero out the whole struct to be safe.

Fixes: 4ba66093bdc6 ("IB/core: Check for global flag when using ah_attr")
Reported-by: TCS Robot <tcs_robot@tencent.com>
Signed-off-by: Haimin Zhang <tcs.kernel@gmail.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
Resending through the regular lists.

I added parentheses around the sizeof to make checkpatch happy.
s/sizeof resp/sizeof(resp)/.

 drivers/infiniband/core/ucma.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/infiniband/core/ucma.c b/drivers/infiniband/core/ucma.c
index 9d6ac9dff39a..91485f13d842 100644
--- a/drivers/infiniband/core/ucma.c
+++ b/drivers/infiniband/core/ucma.c
@@ -1232,7 +1232,7 @@ static ssize_t ucma_init_qp_attr(struct ucma_file *file,
 	if (IS_ERR(ctx))
 		return PTR_ERR(ctx);
 
-	resp.qp_attr_mask = 0;
+	memset(&resp, 0, sizeof(resp));
 	memset(&qp_attr, 0, sizeof qp_attr);
 	qp_attr.qp_state = cmd.qp_state;
 	mutex_lock(&ctx->mutex);
-- 
2.20.1