[PATCH 3.4 24/43] IB/ehca: Returns an error on ib_copy_to_udata() failure

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

3.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Yann Droneaud <ydroneaud@opteya.com>

commit 5bdb0f02add5994b0bc17494f4726925ca5d6ba1 upstream.

In case of error when writing to userspace, function ehca_create_cq()
does not set an error code before following its error path.

This patch sets the error code to -EFAULT when ib_copy_to_udata()
fails.

This was caught when using spatch (aka. coccinelle)
to rewrite call to ib_copy_{from,to}_udata().

Link: https://www.gitorious.org/opteya/coccib/source/75ebf2c1033c64c1d81df13e4ae44ee99c989eba:ib_copy_udata.cocci
Link: http://marc.info/?i=cover.1394485254.git.ydroneaud@opteya.com
Signed-off-by: Yann Droneaud <ydroneaud@opteya.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/infiniband/hw/ehca/ehca_cq.c |    1 +
 1 file changed, 1 insertion(+)

--- a/drivers/infiniband/hw/ehca/ehca_cq.c
+++ b/drivers/infiniband/hw/ehca/ehca_cq.c
@@ -296,6 +296,7 @@ struct ib_cq *ehca_create_cq(struct ib_d
 			(my_cq->galpas.user.fw_handle & (PAGE_SIZE - 1));
 		if (ib_copy_to_udata(udata, &resp, sizeof(resp))) {
 			ehca_err(device, "Copy to udata failed.");
+			cq = ERR_PTR(-EFAULT);
 			goto create_cq_exit4;
 		}
 	}