AMD-GFX Archive on lore.kernel.org
 help / color / mirror / Atom feed
From: Defang Bo <bodefang@126.com>
To: airlied@linux.ie, daniel@ffwll.ch
Cc: Defang Bo <bodefang@126.com>,
	dri-devel@lists.freedesktop.org, amd-gfx@lists.freedesktop.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH] drm/amd/display: avoid null pointer dereference in dm_set_vblank
Date: Fri, 25 Dec 2020 14:24:27 +0800	[thread overview]
Message-ID: <1608877467-2270263-1-git-send-email-bodefang@126.com> (raw)

[Why]
Similar to commit<dddc0557e>("drm/amd/display: Guard against null crtc in CRC IRQ"),
a null pointer deference can occur if crtc is null in
dm_set_vblank.

[How]

Check that CRTC is non-null before accessing its fields.

Signed-off-by: Defang Bo <bodefang@126.com>
---
 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index e2b23486..df23d28 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -4875,10 +4875,17 @@ static inline int dm_set_vupdate_irq(struct drm_crtc *crtc, bool enable)
 static inline int dm_set_vblank(struct drm_crtc *crtc, bool enable)
 {
 	enum dc_irq_source irq_source;
-	struct amdgpu_crtc *acrtc = to_amdgpu_crtc(crtc);
-	struct amdgpu_device *adev = drm_to_adev(crtc->dev);
-	struct dm_crtc_state *acrtc_state = to_dm_crtc_state(crtc->state);
+	struct amdgpu_crtc *acrtc;
+	struct amdgpu_device *adev;
+	struct dm_crtc_state *acrtc_state;
 	int rc = 0;
+
+	if (crtc == NULL)
+		return rc;
+
+	acrtc = to_amdgpu_crtc(crtc);
+	adev = drm_to_adev(crtc->dev);
+	acrtc_state = to_dm_crtc_state(crtc->state);
 
 	if (enable) {
 		/* vblank irq on -> Only need vupdate irq in vrr mode */
-- 
2.7.4

_______________________________________________
amd-gfx mailing list
amd-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/amd-gfx

             reply	other threads:[~2020-12-25  9:43 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-12-25  6:24 Defang Bo [this message]
  -- strict thread matches above, loose matches on Subject: below --
2020-12-28  3:57 [PATCH] drm/amd/display: avoid null pointer dereference in dm_set_vblank Defang Bo

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1608877467-2270263-1-git-send-email-bodefang@126.com \
    --to=bodefang@126.com \
    --cc=airlied@linux.ie \
    --cc=amd-gfx@lists.freedesktop.org \
    --cc=daniel@ffwll.ch \
    --cc=dri-devel@lists.freedesktop.org \
    --cc=linux-kernel@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox