[4.2.y-ckt stable] Patch "libnvdimm: Fix security issue with DSM IOCTL." has been added to the 4.2.y-ckt tree

[Kamal Mostafa]

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

    libnvdimm: Fix security issue with DSM IOCTL.

to the linux-4.2.y-queue branch of the 4.2.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-4.2.y-queue

This patch is scheduled to be released in version 4.2.8-ckt7.

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

For more information about the 4.2.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

---8<------------------------------------------------------------

>From b614925d3397ba4d9f76964e8639a9b0fc37da84 Mon Sep 17 00:00:00 2001
From: Jerry Hoemann <jerry.hoemann at hpe.com>
Date: Wed, 6 Jan 2016 16:03:41 -0700
Subject: libnvdimm: Fix security issue with DSM IOCTL.

commit 07accfa9d1a8bac8262f6d24a94a54d2d1f35149 upstream.

Code attempts to prevent certain IOCTL DSM from being called
when device is opened read only.  This security feature can
be trivially overcome by changing the size portion of the
ioctl_command which isn't used.

Check only the _IOC_NR (i.e. the command).

Signed-off-by: Jerry Hoemann <jerry.hoemann at hpe.com>
Signed-off-by: Dan Williams <dan.j.williams at intel.com>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/nvdimm/bus.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/nvdimm/bus.c b/drivers/nvdimm/bus.c
index 7e2c43f..496b9b6 100644
--- a/drivers/nvdimm/bus.c
+++ b/drivers/nvdimm/bus.c
@@ -513,10 +513,10 @@ static int __nd_ioctl(struct nvdimm_bus *nvdimm_bus, struct nvdimm *nvdimm,

 	/* fail write commands (when read-only) */
 	if (read_only)
-		switch (ioctl_cmd) {
-		case ND_IOCTL_VENDOR:
-		case ND_IOCTL_SET_CONFIG_DATA:
-		case ND_IOCTL_ARS_START:
+		switch (cmd) {
+		case ND_CMD_VENDOR:
+		case ND_CMD_SET_CONFIG_DATA:
+		case ND_CMD_ARS_START:
 			dev_dbg(&nvdimm_bus->dev, "'%s' command while read-only.\n",
 					nvdimm ? nvdimm_cmd_name(cmd)
 					: nvdimm_bus_cmd_name(cmd));
--
2.7.4