Commit 12ec9f92 authored Mar 22, 2019 by Jean-Philippe Brucker Committed by Greg Kroah-Hartman May 04, 2019

drm/meson: Uninstall IRQ handler



[ Upstream commit 2d8f92897ad816f5dda54b2ed2fd9f2d7cb1abde ]

meson_drv_unbind() doesn't unregister the IRQ handler, which can lead to
use-after-free if the IRQ fires after unbind:

[   64.656876] Unable to handle kernel paging request at virtual address ffff000011706dbc
...
[   64.662001] pc : meson_irq+0x18/0x30 [meson_drm]

I'm assuming that a similar problem could happen on the error path of
bind(), so uninstall the IRQ handler there as well.

Fixes: bbbe775e ("drm: Add support for Amlogic Meson Graphic Controller")
Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190322152657.13752-2-jean-philippe.brucker@arm.com


Signed-off-by: Sasha Levin (Microsoft) <sashal@kernel.org>

parent afc0ca59

drivers/gpu/drm/meson/meson_drv.c

+4 −1

Original line number	Diff line number	Diff line
		@@ -277,10 +277,12 @@ static int meson_drv_bind_master(struct device *dev, bool has_components)

		ret = drm_dev_register(drm, 0);
		if (ret)
		goto free_drm;
		goto uninstall_irq;

		return 0;

		uninstall_irq:
		drm_irq_uninstall(drm);
		free_drm:
		drm_dev_unref(drm);

		@@ -298,6 +300,7 @@ static void meson_drv_unbind(struct device *dev)
		struct drm_device *drm = priv->drm;

		drm_dev_unregister(drm);
		drm_irq_uninstall(drm);
		drm_kms_helper_poll_fini(drm);
		drm_fbdev_cma_fini(priv->fbdev);
		drm_mode_config_cleanup(drm);