[ 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@xxxxxxx>
Acked-by: Neil Armstrong <narmstrong@xxxxxxxxxxxx>
Signed-off-by: Neil Armstrong <narmstrong@xxxxxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20190322152657.13752-2-jean-philippe.brucker@xxxxxxx
Signed-off-by: Sasha Levin (Microsoft) <sashal@xxxxxxxxxx>
---
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 4a72fa53a1d5..588b3b0c8315 100644
--- a/drivers/gpu/drm/meson/meson_drv.c
+++ b/drivers/gpu/drm/meson/meson_drv.c
@@ -300,10 +300,12 @@ 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_put(drm);
@@ -321,6 +323,7 @@ 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);
--
2.19.1
