[ 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: bbbe775ec5b5 ("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-ph... Signed-off-by: Sasha Levin (Microsoft) sashal@kernel.org --- drivers/gpu/drm/meson/meson_drv.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/meson/meson_drv.c b/drivers/gpu/drm/meson/meson_drv.c index 1a1b0b9cf1fa..0608243c3387 100644 --- a/drivers/gpu/drm/meson/meson_drv.c +++ b/drivers/gpu/drm/meson/meson_drv.c @@ -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);