[PATCH 3.18 10/38] drm/sti: sti_vtg: Handle return NULL error from devm_ioremap_nocache

Greg Kroah-Hartman
2017-11-19T14:30:04Z

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
@@ -303,6 +303,10 @@ 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) {