3.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Arvind Yadav <arvind.yadav.cs@xxxxxxxxx> [ 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@xxxxxxxxx> Acked-by: Vincent Abriou <vincent.abriou@xxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- 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) {