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From: Defang Bo <bodefang@126.com>
To: airlied@linux.ie, daniel@ffwll.ch
Cc: alexander.deucher@amd.com, Defang Bo <bodefang@126.com>,
	dri-devel@lists.freedesktop.org, amd-gfx@lists.freedesktop.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH] drm/radeon:avoid null pointer dereference when dev is not bound
Date: Sun, 27 Dec 2020 16:24:29 +0800	[thread overview]
Message-ID: <1609057469-3844200-1-git-send-email-bodefang@126.com> (raw)

[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
-- 
2.7.4

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             reply	other threads:[~2020-12-27 20:56 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-12-27  8:24 Defang Bo [this message]
2021-01-04 17:00 ` [PATCH] drm/radeon:avoid null pointer dereference when dev is not bound Alex Deucher
2021-01-05  2:43   ` bodefang

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