linux-kernel - [PATCH 1/2][next][V2] Fix dereference of pointer minor before null check

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250731081854.2120404-2-colin.i.king@gmail.com>
Date: Thu, 31 Jul 2025 09:18:53 +0100
From: Colin Ian King <colin.i.king@...il.com>
To: Rob Clark <robin.clark@....qualcomm.com>,
	Abhinav Kumar <abhinav.kumar@...ux.dev>,
	Jessica Zhang <jessica.zhang@....qualcomm.com>,
	Sean Paul <sean@...rly.run>,
	Marijn Suijten <marijn.suijten@...ainline.org>,
	David Airlie <airlied@...il.com>,
	Simona Vetter <simona@...ll.ch>,
	linux-arm-msm@...r.kernel.org,
	dri-devel@...ts.freedesktop.org,
	freedreno@...ts.freedesktop.org
Cc: kernel-janitors@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: [PATCH 1/2][next][V2] Fix dereference of pointer minor before null check

Currently the pointer minor is being dereferenced before it is null
checked, leading to a potential null pointer dereference issue. Fix this
by dereferencing the pointer only after it has been null checked.

Fixes: 4f89cf40d01e ("drm/msm: bail out late_init_minor() if it is not a GPU device")
Signed-off-by: Colin Ian King <colin.i.king@...il.com>
---
 drivers/gpu/drm/msm/msm_debugfs.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/msm/msm_debugfs.c b/drivers/gpu/drm/msm/msm_debugfs.c
index bbda865addae..da618720cf8a 100644
--- a/drivers/gpu/drm/msm/msm_debugfs.c
+++ b/drivers/gpu/drm/msm/msm_debugfs.c
@@ -325,13 +325,16 @@ static struct drm_info_list msm_debugfs_list[] = {
 
 static int late_init_minor(struct drm_minor *minor)
 {
-	struct drm_device *dev = minor->dev;
-	struct msm_drm_private *priv = dev->dev_private;
+	struct drm_device *dev;
+	struct msm_drm_private *priv;
 	int ret;
 
 	if (!minor)
 		return 0;
 
+	dev = minor->dev;
+	priv = dev->dev_private;
+
 	if (!priv->gpu_pdev)
 		return 0;
 
-- 

V2: remove changes of minor->dev->dev to dev->dev, put them in 2nd patch

--
2.50.0