lkml.org 
[lkml]   [2021]   [Jan]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [PATCH] drm/radeon:avoid null pointer dereference when dev is not bound
On Sun, Dec 27, 2020 at 3:56 PM Defang Bo <bodefang@126.com> wrote:
>
> [Why]
> Similar to commit<0fa375e6>. If the set_state/can_switch code access the drm_device when dev is not bound,
> a null pointer dereference can happen.
>
> [How]
> Add sanity checks to prevent it.
>
> Signed-off-by: Defang Bo <bodefang@126.com>

Are you actually hitting this or is this just defensive? I don't
think we can actually get into a state where this would be a problem.

Alex

> ---
> drivers/gpu/drm/radeon/radeon_device.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/drivers/gpu/drm/radeon/radeon_device.c b/drivers/gpu/drm/radeon/radeon_device.c
> index 266e3cb..50a1a60 100644
> --- a/drivers/gpu/drm/radeon/radeon_device.c
> +++ b/drivers/gpu/drm/radeon/radeon_device.c
> @@ -1224,6 +1224,9 @@ static void radeon_switcheroo_set_state(struct pci_dev *pdev, enum vga_switchero
> {
> struct drm_device *dev = pci_get_drvdata(pdev);
>
> + if (!dev)
> + return;
> +
> if (radeon_is_px(dev) && state == VGA_SWITCHEROO_OFF)
> return;
>
> @@ -1257,6 +1260,9 @@ static void radeon_switcheroo_set_state(struct pci_dev *pdev, enum vga_switchero
> static bool radeon_switcheroo_can_switch(struct pci_dev *pdev)
> {
> struct drm_device *dev = pci_get_drvdata(pdev);
> +
> + if (!dev)
> + return false;
>
> /*
> * FIXME: open_count is protected by drm_global_mutex but that would lead to
> --
> 2.7.4
>
> _______________________________________________
> amd-gfx mailing list
> amd-gfx@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/amd-gfx

\
 
 \ /
  Last update: 2021-01-04 18:03    [W:0.040 / U:0.944 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site