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From: Anirudh Rayabharam <mail@anirudhrb.com>
To: Ferenc Bakonyi <fero@drama.obuda.kando.hu>,
	Igor Matheus Andrade Torrente <igormtorrente@gmail.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-kernel-mentees@lists.linuxfoundation.org,
	Anirudh Rayabharam <mail@anirudhrb.com>,
	kernel test robot <oliver.sang@intel.com>,
	stable <stable@vger.kernel.org>,
	linux-nvidia@lists.surfsouth.com,
	dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH] video: hgafb: correctly handle card detect failure during probe
Date: Mon, 17 May 2021 00:57:14 +0530	[thread overview]
Message-ID: <20210516192714.25823-1-mail@anirudhrb.com> (raw)

The return value of hga_card_detect() is not properly handled causing
the probe to succeed even though hga_card_detect() failed. Since probe
succeeds, hgafb_open() can be called which will end up operating on an
unmapped hga_vram. This results in an out-of-bounds access as reported
by kernel test robot [1].

To fix this, correctly detect failure of hga_card_detect() by checking
for a non-zero error code.

[1]: https://lore.kernel.org/lkml/20210516150019.GB25903@xsang-OptiPlex-9020/

Reported-by: kernel test robot <oliver.sang@intel.com>
Fixes: dc13cac4862c ("video: hgafb: fix potential NULL pointer dereference")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Anirudh Rayabharam <mail@anirudhrb.com>
---
 drivers/video/fbdev/hgafb.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/video/fbdev/hgafb.c b/drivers/video/fbdev/hgafb.c
index cc8e62ae93f6..bd3d07aa4f0e 100644
--- a/drivers/video/fbdev/hgafb.c
+++ b/drivers/video/fbdev/hgafb.c
@@ -558,7 +558,7 @@ static int hgafb_probe(struct platform_device *pdev)
 	int ret;
 
 	ret = hga_card_detect();
-	if (!ret)
+	if (ret)
 		return ret;
 
 	printk(KERN_INFO "hgafb: %s with %ldK of memory detected.\n",
-- 
2.26.2


WARNING: multiple messages have this Message-ID (diff)
From: Anirudh Rayabharam <mail@anirudhrb.com>
To: Ferenc Bakonyi <fero@drama.obuda.kando.hu>,
	Igor Matheus Andrade Torrente <igormtorrente@gmail.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org,
	dri-devel@lists.freedesktop.org,
	kernel test robot <oliver.sang@intel.com>,
	stable <stable@vger.kernel.org>,
	linux-nvidia@lists.surfsouth.com,
	linux-kernel-mentees@lists.linuxfoundation.org
Subject: [PATCH] video: hgafb: correctly handle card detect failure during probe
Date: Mon, 17 May 2021 00:57:14 +0530	[thread overview]
Message-ID: <20210516192714.25823-1-mail@anirudhrb.com> (raw)

The return value of hga_card_detect() is not properly handled causing
the probe to succeed even though hga_card_detect() failed. Since probe
succeeds, hgafb_open() can be called which will end up operating on an
unmapped hga_vram. This results in an out-of-bounds access as reported
by kernel test robot [1].

To fix this, correctly detect failure of hga_card_detect() by checking
for a non-zero error code.

[1]: https://lore.kernel.org/lkml/20210516150019.GB25903@xsang-OptiPlex-9020/

Reported-by: kernel test robot <oliver.sang@intel.com>
Fixes: dc13cac4862c ("video: hgafb: fix potential NULL pointer dereference")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Anirudh Rayabharam <mail@anirudhrb.com>
---
 drivers/video/fbdev/hgafb.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/video/fbdev/hgafb.c b/drivers/video/fbdev/hgafb.c
index cc8e62ae93f6..bd3d07aa4f0e 100644
--- a/drivers/video/fbdev/hgafb.c
+++ b/drivers/video/fbdev/hgafb.c
@@ -558,7 +558,7 @@ static int hgafb_probe(struct platform_device *pdev)
 	int ret;
 
 	ret = hga_card_detect();
-	if (!ret)
+	if (ret)
 		return ret;
 
 	printk(KERN_INFO "hgafb: %s with %ldK of memory detected.\n",
-- 
2.26.2

_______________________________________________
Linux-kernel-mentees mailing list
Linux-kernel-mentees@lists.linuxfoundation.org
https://lists.linuxfoundation.org/mailman/listinfo/linux-kernel-mentees

WARNING: multiple messages have this Message-ID (diff)
From: Anirudh Rayabharam <mail@anirudhrb.com>
To: Ferenc Bakonyi <fero@drama.obuda.kando.hu>,
	Igor Matheus Andrade Torrente <igormtorrente@gmail.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org,
	dri-devel@lists.freedesktop.org,
	Anirudh Rayabharam <mail@anirudhrb.com>,
	kernel test robot <oliver.sang@intel.com>,
	stable <stable@vger.kernel.org>,
	linux-nvidia@lists.surfsouth.com,
	linux-kernel-mentees@lists.linuxfoundation.org
Subject: [PATCH] video: hgafb: correctly handle card detect failure during probe
Date: Mon, 17 May 2021 00:57:14 +0530	[thread overview]
Message-ID: <20210516192714.25823-1-mail@anirudhrb.com> (raw)

The return value of hga_card_detect() is not properly handled causing
the probe to succeed even though hga_card_detect() failed. Since probe
succeeds, hgafb_open() can be called which will end up operating on an
unmapped hga_vram. This results in an out-of-bounds access as reported
by kernel test robot [1].

To fix this, correctly detect failure of hga_card_detect() by checking
for a non-zero error code.

[1]: https://lore.kernel.org/lkml/20210516150019.GB25903@xsang-OptiPlex-9020/

Reported-by: kernel test robot <oliver.sang@intel.com>
Fixes: dc13cac4862c ("video: hgafb: fix potential NULL pointer dereference")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Anirudh Rayabharam <mail@anirudhrb.com>
---
 drivers/video/fbdev/hgafb.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/video/fbdev/hgafb.c b/drivers/video/fbdev/hgafb.c
index cc8e62ae93f6..bd3d07aa4f0e 100644
--- a/drivers/video/fbdev/hgafb.c
+++ b/drivers/video/fbdev/hgafb.c
@@ -558,7 +558,7 @@ static int hgafb_probe(struct platform_device *pdev)
 	int ret;
 
 	ret = hga_card_detect();
-	if (!ret)
+	if (ret)
 		return ret;
 
 	printk(KERN_INFO "hgafb: %s with %ldK of memory detected.\n",
-- 
2.26.2


             reply	other threads:[~2021-05-16 19:27 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-16 19:27 Anirudh Rayabharam [this message]
2021-05-16 19:27 ` [PATCH] video: hgafb: correctly handle card detect failure during probe Anirudh Rayabharam
2021-05-16 19:27 ` Anirudh Rayabharam
2021-05-17 12:27 ` Igor Torrente
2021-05-17 12:27   ` Igor Torrente
2021-05-17 12:27   ` Igor Torrente
2021-05-20 13:40 ` Anirudh Rayabharam
2021-05-20 13:40   ` Anirudh Rayabharam
2021-05-20 13:40   ` Anirudh Rayabharam
2021-05-20 13:58   ` Greg Kroah-Hartman
2021-05-20 13:58     ` Greg Kroah-Hartman
2021-05-20 13:58     ` Greg Kroah-Hartman

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