* [PATCH AUTOSEL 5.0 56/98] drm/meson: Fix invalid pointer in meson_drv_unbind()
[not found] <20190422194205.10404-1-sashal@kernel.org>
@ 2019-04-22 19:41 ` Sasha Levin
2019-04-22 19:41 ` [PATCH AUTOSEL 5.0 57/98] drm/meson: Uninstall IRQ handler Sasha Levin
1 sibling, 0 replies; 2+ messages in thread
From: Sasha Levin @ 2019-04-22 19:41 UTC (permalink / raw)
To: linux-kernel, stable
Cc: Jean-Philippe Brucker, Sasha Levin, linux-amlogic, dri-devel,
Neil Armstrong
From: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
[ Upstream commit 776e78677f514ecddd12dba48b9040958999bd5a ]
meson_drv_bind() registers a meson_drm struct as the device's privdata,
but meson_drv_unbind() tries to retrieve a drm_device. This may cause a
segfault on shutdown:
[ 5194.593429] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000197
...
[ 5194.788850] Call trace:
[ 5194.791349] drm_dev_unregister+0x1c/0x118 [drm]
[ 5194.795848] meson_drv_unbind+0x50/0x78 [meson_drm]
Retrieve the right pointer in meson_drv_unbind().
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/20190322152657.13752-1-jean-philippe.brucker@arm.com
Signed-off-by: Sasha Levin (Microsoft) <sashal@kernel.org>
---
drivers/gpu/drm/meson/meson_drv.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/meson/meson_drv.c b/drivers/gpu/drm/meson/meson_drv.c
index 12ff47b13668..c1115a96453f 100644
--- a/drivers/gpu/drm/meson/meson_drv.c
+++ b/drivers/gpu/drm/meson/meson_drv.c
@@ -336,8 +336,8 @@ static int meson_drv_bind(struct device *dev)
static void meson_drv_unbind(struct device *dev)
{
- struct drm_device *drm = dev_get_drvdata(dev);
- struct meson_drm *priv = drm->dev_private;
+ struct meson_drm *priv = dev_get_drvdata(dev);
+ struct drm_device *drm = priv->drm;
if (priv->canvas) {
meson_canvas_free(priv->canvas, priv->canvas_id_osd1);
--
2.19.1
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^ permalink raw reply related [flat|nested] 2+ messages in thread
* [PATCH AUTOSEL 5.0 57/98] drm/meson: Uninstall IRQ handler
[not found] <20190422194205.10404-1-sashal@kernel.org>
2019-04-22 19:41 ` [PATCH AUTOSEL 5.0 56/98] drm/meson: Fix invalid pointer in meson_drv_unbind() Sasha Levin
@ 2019-04-22 19:41 ` Sasha Levin
1 sibling, 0 replies; 2+ messages in thread
From: Sasha Levin @ 2019-04-22 19:41 UTC (permalink / raw)
To: linux-kernel, stable
Cc: Jean-Philippe Brucker, Sasha Levin, linux-amlogic, dri-devel,
Neil Armstrong
From: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
[ 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-philippe.brucker@arm.com
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 c1115a96453f..a13704ab5d11 100644
--- a/drivers/gpu/drm/meson/meson_drv.c
+++ b/drivers/gpu/drm/meson/meson_drv.c
@@ -317,12 +317,14 @@ 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;
drm_fbdev_generic_setup(drm, 32);
return 0;
+uninstall_irq:
+ drm_irq_uninstall(drm);
free_drm:
drm_dev_put(drm);
@@ -347,6 +349,7 @@ static void meson_drv_unbind(struct device *dev)
}
drm_dev_unregister(drm);
+ drm_irq_uninstall(drm);
drm_kms_helper_poll_fini(drm);
drm_mode_config_cleanup(drm);
drm_dev_put(drm);
--
2.19.1
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2019-04-22 19:41 ` [PATCH AUTOSEL 5.0 56/98] drm/meson: Fix invalid pointer in meson_drv_unbind() Sasha Levin
2019-04-22 19:41 ` [PATCH AUTOSEL 5.0 57/98] drm/meson: Uninstall IRQ handler Sasha Levin
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