linux-kernel - [PATCH next] drm/fsl-dcu: prevent error pointer dereference in fsl_dcu

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-next>] [day] [month] [year] [list]

Message-ID: <e4e078ed-9342-48f4-80c5-28f0f7b711b0@stanley.mountain>
Date: Wed, 23 Oct 2024 11:35:42 +0300
From: Dan Carpenter <dan.carpenter@...aro.org>
To: Matthias Schiffer <matthias.schiffer@...group.com>
Cc: Stefan Agner <stefan@...er.ch>, Alison Wang <alison.wang@....com>,
	Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
	Maxime Ripard <mripard@...nel.org>,
	Thomas Zimmermann <tzimmermann@...e.de>,
	David Airlie <airlied@...il.com>, Simona Vetter <simona@...ll.ch>,
	Dmitry Baryshkov <dmitry.baryshkov@...aro.org>,
	Alexander Stein <alexander.stein@...tq-group.com>,
	dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org,
	kernel-janitors@...r.kernel.org
Subject: [PATCH next] drm/fsl-dcu: prevent error pointer dereference in
 fsl_dcu_load()

The syscon_regmap_lookup_by_compatible() function returns -ENODEV if
there isn't a compatible for it or other error pointers on error.  This
code only checks for -ENODEV instead of checking for other errors so it
could lead to an error pointer dereference inside the regmap_update_bits()
function.

Fixes: ffcde9e44d3e ("drm: fsl-dcu: enable PIXCLK on LS1021A")
Signed-off-by: Dan Carpenter <dan.carpenter@...aro.org>
---
 drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c
index 91a48d774cf7..5997d9b4a431 100644
--- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c
+++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c
@@ -109,7 +109,9 @@ static int fsl_dcu_load(struct drm_device *dev, unsigned long flags)
 		return dev_err_probe(dev->dev, ret, "failed to initialize mode setting\n");
 
 	scfg = syscon_regmap_lookup_by_compatible("fsl,ls1021a-scfg");
-	if (PTR_ERR(scfg) != -ENODEV) {
+	if (IS_ERR(scfg) && PTR_ERR(scfg) != -ENODEV)
+		return dev_err_probe(dev->dev, PTR_ERR(scfg), "failed to find regmap\n");
+	if (!IS_ERR(scfg)) {
 		/*
 		 * For simplicity, enable the PIXCLK unconditionally,
 		 * resulting in increased power consumption. Disabling
-- 
2.45.2