[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 --- 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
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
I use static analysis tool to find these funcs are similar to the commit<0fa375e6bc90>(drm/rockchip: Fix suspend crash when drm is not bound),so it's just defensive, I haven't actually hitted this.
At 2021-01-05 01:00:27, "Alex Deucher" alexdeucher@gmail.com wrote:
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
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dri-devel@lists.freedesktop.org
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Defang Bo