[3.8.y.z extended stable] Patch "IB/mthca: Return an error on ib_copy_to_udata() failure" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    IB/mthca: Return an error on ib_copy_to_udata() failure

to the linux-3.8.y-queue branch of the 3.8.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.8.y-queue

This patch is scheduled to be released in version 3.8.13.22.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.8.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From b292f3030d8092ddd8da1164783049cf28d1305e Mon Sep 17 00:00:00 2001
From: Yann Droneaud <ydroneaud at opteya.com>
Date: Mon, 10 Mar 2014 23:06:26 +0100
Subject: IB/mthca: Return an error on ib_copy_to_udata() failure

commit 08e74c4b00c30c232d535ff368554959403d0432 upstream.

In case of error when writing to userspace, the function mthca_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 at opteya.com>
Signed-off-by: Roland Dreier <roland at purestorage.com>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/infiniband/hw/mthca/mthca_provider.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/infiniband/hw/mthca/mthca_provider.c b/drivers/infiniband/hw/mthca/mthca_provider.c
index 5b71d43..42dde06 100644
--- a/drivers/infiniband/hw/mthca/mthca_provider.c
+++ b/drivers/infiniband/hw/mthca/mthca_provider.c
@@ -695,6 +695,7 @@ static struct ib_cq *mthca_create_cq(struct ib_device *ibdev, int entries,

 	if (context && ib_copy_to_udata(udata, &cq->cqn, sizeof (__u32))) {
 		mthca_free_cq(to_mdev(ibdev), cq);
+		err = -EFAULT;
 		goto err_free;
 	}

--
1.9.1