* [PATCH 1/2] drm/meson: Fix invalid pointer in meson_drv_unbind()
@ 2019-03-22 15:26 Jean-Philippe Brucker
2019-03-22 15:26 ` [PATCH 2/2] drm/meson: Uninstall IRQ handler Jean-Philippe Brucker
` (2 more replies)
0 siblings, 3 replies; 5+ messages in thread
From: Jean-Philippe Brucker @ 2019-03-22 15:26 UTC (permalink / raw)
To: narmstrong
Cc: airlied, khilman, dri-devel, daniel, linux-amlogic, linux-arm-kernel
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>
---
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 2281ed3eb774..7e85802c5398 100644
--- a/drivers/gpu/drm/meson/meson_drv.c
+++ b/drivers/gpu/drm/meson/meson_drv.c
@@ -356,8 +356,8 @@ 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);
--
2.20.1
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^ permalink raw reply related [flat|nested] 5+ messages in thread* [PATCH 2/2] drm/meson: Uninstall IRQ handler
2019-03-22 15:26 [PATCH 1/2] drm/meson: Fix invalid pointer in meson_drv_unbind() Jean-Philippe Brucker
@ 2019-03-22 15:26 ` Jean-Philippe Brucker
2019-03-23 9:54 ` Neil Armstrong
2019-03-23 9:53 ` [PATCH 1/2] drm/meson: Fix invalid pointer in meson_drv_unbind() Neil Armstrong
2019-03-25 10:19 ` Neil Armstrong
2 siblings, 1 reply; 5+ messages in thread
From: Jean-Philippe Brucker @ 2019-03-22 15:26 UTC (permalink / raw)
To: narmstrong
Cc: airlied, khilman, dri-devel, daniel, linux-amlogic, linux-arm-kernel
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>
---
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 7e85802c5398..8a4ebcb6405c 100644
--- a/drivers/gpu/drm/meson/meson_drv.c
+++ b/drivers/gpu/drm/meson/meson_drv.c
@@ -337,12 +337,14 @@ 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);
@@ -367,6 +369,7 @@ 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);
--
2.20.1
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^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [PATCH 2/2] drm/meson: Uninstall IRQ handler
2019-03-22 15:26 ` [PATCH 2/2] drm/meson: Uninstall IRQ handler Jean-Philippe Brucker
@ 2019-03-23 9:54 ` Neil Armstrong
0 siblings, 0 replies; 5+ messages in thread
From: Neil Armstrong @ 2019-03-23 9:54 UTC (permalink / raw)
To: Jean-Philippe Brucker
Cc: airlied, khilman, dri-devel, daniel, linux-amlogic, linux-arm-kernel
Hi Jean-Philippe,
Le 22/03/2019 16:26, Jean-Philippe Brucker a écrit :
> 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>
> ---
> drivers/gpu/drm/meson/meson_drv.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
Thanks for working on this,
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
I'll push it on drm-misc-fixes
>
> diff --git a/drivers/gpu/drm/meson/meson_drv.c b/drivers/gpu/drm/meson/meson_drv.c
> index 7e85802c5398..8a4ebcb6405c 100644
> --- a/drivers/gpu/drm/meson/meson_drv.c
> +++ b/drivers/gpu/drm/meson/meson_drv.c
> @@ -337,12 +337,14 @@ 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);
>
> @@ -367,6 +369,7 @@ 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);
>
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^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH 1/2] drm/meson: Fix invalid pointer in meson_drv_unbind()
2019-03-22 15:26 [PATCH 1/2] drm/meson: Fix invalid pointer in meson_drv_unbind() Jean-Philippe Brucker
2019-03-22 15:26 ` [PATCH 2/2] drm/meson: Uninstall IRQ handler Jean-Philippe Brucker
@ 2019-03-23 9:53 ` Neil Armstrong
2019-03-25 10:19 ` Neil Armstrong
2 siblings, 0 replies; 5+ messages in thread
From: Neil Armstrong @ 2019-03-23 9:53 UTC (permalink / raw)
To: Jean-Philippe Brucker
Cc: airlied, khilman, dri-devel, daniel, linux-amlogic, linux-arm-kernel
Hi Jean-Philippe,
Le 22/03/2019 16:26, Jean-Philippe Brucker a écrit :
> 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>
Thanks for working on this,
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
I'll push it on drm-misc-fixes
> ---
> 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 2281ed3eb774..7e85802c5398 100644
> --- a/drivers/gpu/drm/meson/meson_drv.c
> +++ b/drivers/gpu/drm/meson/meson_drv.c
> @@ -356,8 +356,8 @@ 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);
>
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^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH 1/2] drm/meson: Fix invalid pointer in meson_drv_unbind()
2019-03-22 15:26 [PATCH 1/2] drm/meson: Fix invalid pointer in meson_drv_unbind() Jean-Philippe Brucker
2019-03-22 15:26 ` [PATCH 2/2] drm/meson: Uninstall IRQ handler Jean-Philippe Brucker
2019-03-23 9:53 ` [PATCH 1/2] drm/meson: Fix invalid pointer in meson_drv_unbind() Neil Armstrong
@ 2019-03-25 10:19 ` Neil Armstrong
2 siblings, 0 replies; 5+ messages in thread
From: Neil Armstrong @ 2019-03-25 10:19 UTC (permalink / raw)
To: Jean-Philippe Brucker
Cc: airlied, khilman, dri-devel, daniel, linux-amlogic, linux-arm-kernel
On 22/03/2019 16:26, Jean-Philippe Brucker wrote:
> 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>
> ---
> 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 2281ed3eb774..7e85802c5398 100644
> --- a/drivers/gpu/drm/meson/meson_drv.c
> +++ b/drivers/gpu/drm/meson/meson_drv.c
> @@ -356,8 +356,8 @@ 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);
>
Applied both to drm-misc-fixes, thanks !
Neil
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^ permalink raw reply [flat|nested] 5+ messages in thread
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2019-03-22 15:26 [PATCH 1/2] drm/meson: Fix invalid pointer in meson_drv_unbind() Jean-Philippe Brucker
2019-03-22 15:26 ` [PATCH 2/2] drm/meson: Uninstall IRQ handler Jean-Philippe Brucker
2019-03-23 9:54 ` Neil Armstrong
2019-03-23 9:53 ` [PATCH 1/2] drm/meson: Fix invalid pointer in meson_drv_unbind() Neil Armstrong
2019-03-25 10:19 ` Neil Armstrong
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