Messages in this thread | | | From | Alex Deucher <> | Date | Mon, 4 Jan 2021 12:00:27 -0500 | Subject | Re: [PATCH] drm/radeon:avoid null pointer dereference when dev is not bound |
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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
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