Patch "drm/sti: sti_vtg: Handle return NULL error from devm_ioremap_nocache" has been added to the 4.4-stable tree

Patch "drm/sti: sti_vtg: Handle return NULL error from devm_ioremap_nocache" has been added to the 4.4-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    drm/sti: sti_vtg: Handle return NULL error from devm_ioremap_nocache

to the 4.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     drm-sti-sti_vtg-handle-return-null-error-from-devm_ioremap_nocache.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From foo@baz Sun Nov 19 12:02:55 CET 2017
From: Arvind Yadav <arvind.yadav.cs@gmail.com>
Date: Wed, 21 Dec 2016 11:00:12 +0530
Subject: drm/sti: sti_vtg: Handle return NULL error from devm_ioremap_nocache

From: Arvind Yadav <arvind.yadav.cs@gmail.com>


[ Upstream commit 1ae0d5af347df224a6e76334683f13a96d915a44 ]

Here, If devm_ioremap_nocache will fail. It will return NULL.
Kernel can run into a NULL-pointer dereference. This error check
will avoid NULL pointer dereference.

Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Acked-by: Vincent Abriou <vincent.abriou@st.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/gpu/drm/sti/sti_vtg.c |    4 ++++
 1 file changed, 4 insertions(+)

--- a/drivers/gpu/drm/sti/sti_vtg.c
+++ b/drivers/gpu/drm/sti/sti_vtg.c
@@ -346,6 +346,10 @@ static int vtg_probe(struct platform_dev
 		return -ENOMEM;
 	}
 	vtg->regs = devm_ioremap_nocache(dev, res->start, resource_size(res));
+	if (!vtg->regs) {
+		DRM_ERROR("failed to remap I/O memory\n");
+		return -ENOMEM;
+	}
 
 	np = of_parse_phandle(pdev->dev.of_node, "st,slave", 0);
 	if (np) {


Patches currently in stable-queue which might be from arvind.yadav.cs@gmail.com are

queue-4.4/gpu-drm-mgag200-mgag200_main-handle-error-from-pci_iomap.patch
queue-4.4/media-imon-fix-null-ptr-deref-in-imon_probe.patch
queue-4.4/drm-sti-sti_vtg-handle-return-null-error-from-devm_ioremap_nocache.patch