* [PATCH] intel, gma500, lvds: Fix use after free on psb_intel_lvds_init()
@ 2012-01-14 19:59 Jesper Juhl
2012-01-14 20:58 ` Jesper Juhl
0 siblings, 1 reply; 5+ messages in thread
From: Jesper Juhl @ 2012-01-14 19:59 UTC (permalink / raw)
To: linux-kernel
Cc: dri-devel, Octavian Purdila, Dave Airlie, Greg Kroah-Hartman,
Alan Cox, David Airlie, Eric Anholt, Jesse Barnes
In psb_intel_lvds_init(), if we fail to allocate memory for
'psb_intel_connector' we free the memory we previously allocated for
'psb_intel_encoder', but we then proceed to use that free'd pointer
when we do 'psb_intel_encoder->dev_priv = lvds_priv;'.
I believe the proper way to handle this is to simply return after the
allocation for 'psb_intel_connector' has failed. That is what this
patch does.
While I was there anyway, I also removed the pointless 'if
(psb_intel_connector)' before freeing it at the 'failed_connector:'
label - kfree() deals gracefully with NULL pointers, so it is not
needed.
Signed-off-by: Jesper Juhl <jj@chaosbits.net>
---
drivers/gpu/drm/gma500/psb_intel_lvds.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)
I considered adding a new label at the end and use a goto instead, but
settled on this minimal solution. If consolidating all exits from the
function is prefered then I can rework the patch to do that
instead. Just let me know.
Patch is compile tested only since I don't have the hardware to
actually test it properly.
diff --git a/drivers/gpu/drm/gma500/psb_intel_lvds.c b/drivers/gpu/drm/gma500/psb_intel_lvds.c
index a25e4ca..7d23ef9 100644
--- a/drivers/gpu/drm/gma500/psb_intel_lvds.c
+++ b/drivers/gpu/drm/gma500/psb_intel_lvds.c
@@ -725,6 +725,7 @@ void psb_intel_lvds_init(struct drm_device *dev,
if (!psb_intel_connector) {
kfree(psb_intel_encoder);
dev_err(dev->dev, "psb_intel_connector allocation error\n");
+ return;
}
lvds_priv = kzalloc(sizeof(struct psb_intel_lvds_priv), GFP_KERNEL);
@@ -862,7 +863,6 @@ failed_blc_i2c:
drm_encoder_cleanup(encoder);
drm_connector_cleanup(connector);
failed_connector:
- if (psb_intel_connector)
- kfree(psb_intel_connector);
+ kfree(psb_intel_connector);
}
--
1.7.8.3
--
Jesper Juhl <jj@chaosbits.net> http://www.chaosbits.net/
Don't top-post http://www.catb.org/jargon/html/T/top-post.html
Plain text mails only, please.
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [PATCH] intel, gma500, lvds: Fix use after free on psb_intel_lvds_init()
2012-01-14 19:59 [PATCH] intel, gma500, lvds: Fix use after free on psb_intel_lvds_init() Jesper Juhl
@ 2012-01-14 20:58 ` Jesper Juhl
2012-01-14 21:15 ` [PATCH] intel, gma500, lvds: Fix use after free and mem leak in psb_intel_lvds_init() Jesper Juhl
0 siblings, 1 reply; 5+ messages in thread
From: Jesper Juhl @ 2012-01-14 20:58 UTC (permalink / raw)
To: linux-kernel
Cc: dri-devel, Octavian Purdila, Dave Airlie, Greg Kroah-Hartman,
Alan Cox, David Airlie, Eric Anholt, Jesse Barnes
On Sat, 14 Jan 2012, Jesper Juhl wrote:
> In psb_intel_lvds_init(), if we fail to allocate memory for
> 'psb_intel_connector' we free the memory we previously allocated for
> 'psb_intel_encoder', but we then proceed to use that free'd pointer
> when we do 'psb_intel_encoder->dev_priv = lvds_priv;'.
>
> I believe the proper way to handle this is to simply return after the
> allocation for 'psb_intel_connector' has failed. That is what this
> patch does.
>
Ok, so I just noticed that we may also leak 'psb_intel_encoder' if we
'goto failed_connector;'. Might as well fix that as well in the same
patch.
So please just ignore this one. I'll submit a new one in a little
while that handles both leaks.
--
Jesper Juhl <jj@chaosbits.net> http://www.chaosbits.net/
Don't top-post http://www.catb.org/jargon/html/T/top-post.html
Plain text mails only, please.
^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH] intel, gma500, lvds: Fix use after free and mem leak in psb_intel_lvds_init()
2012-01-14 20:58 ` Jesper Juhl
@ 2012-01-14 21:15 ` Jesper Juhl
2012-01-17 10:15 ` Patrik Jakobsson
0 siblings, 1 reply; 5+ messages in thread
From: Jesper Juhl @ 2012-01-14 21:15 UTC (permalink / raw)
To: linux-kernel
Cc: dri-devel, Octavian Purdila, Dave Airlie, Greg Kroah-Hartman,
Alan Cox, David Airlie, Eric Anholt, Jesse Barnes
In psb_intel_lvds_init(), if we fail to allocate memory for
'psb_intel_connector' we free the memory we previously allocated for
'psb_intel_encoder', but we then proceed to use that free'd pointer
when we do 'psb_intel_encoder->dev_priv = lvds_priv;'.
We may also leak the memory we allocated for 'psb_intel_encoder' if we
'goto failed_connector;' and the variable goes out of scope.
While I was there anyway, I also removed the pointless 'if
(psb_intel_connector)' before freeing it at the 'failed_connector:'
label - kfree() deals gracefully with NULL pointers, so it is not
needed.
Signed-off-by: Jesper Juhl <jj@chaosbits.net>
---
drivers/gpu/drm/gma500/psb_intel_lvds.c | 9 ++++-----
1 files changed, 4 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/gma500/psb_intel_lvds.c b/drivers/gpu/drm/gma500/psb_intel_lvds.c
index a25e4ca..0a43758 100644
--- a/drivers/gpu/drm/gma500/psb_intel_lvds.c
+++ b/drivers/gpu/drm/gma500/psb_intel_lvds.c
@@ -713,7 +713,6 @@ void psb_intel_lvds_init(struct drm_device *dev,
psb_intel_encoder =
kzalloc(sizeof(struct psb_intel_encoder), GFP_KERNEL);
-
if (!psb_intel_encoder) {
dev_err(dev->dev, "psb_intel_encoder allocation error\n");
return;
@@ -721,10 +720,9 @@ void psb_intel_lvds_init(struct drm_device *dev,
psb_intel_connector =
kzalloc(sizeof(struct psb_intel_connector), GFP_KERNEL);
-
if (!psb_intel_connector) {
- kfree(psb_intel_encoder);
dev_err(dev->dev, "psb_intel_connector allocation error\n");
+ goto failed_encoder;
}
lvds_priv = kzalloc(sizeof(struct psb_intel_lvds_priv), GFP_KERNEL);
@@ -862,7 +860,8 @@ failed_blc_i2c:
drm_encoder_cleanup(encoder);
drm_connector_cleanup(connector);
failed_connector:
- if (psb_intel_connector)
- kfree(psb_intel_connector);
+ kfree(psb_intel_connector);
+failed_encoder:
+ kfree(psb_intel_encoder);
}
--
1.7.8.3
--
Jesper Juhl <jj@chaosbits.net> http://www.chaosbits.net/
Don't top-post http://www.catb.org/jargon/html/T/top-post.html
Plain text mails only, please.
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [PATCH] intel, gma500, lvds: Fix use after free and mem leak in psb_intel_lvds_init()
2012-01-14 21:15 ` [PATCH] intel, gma500, lvds: Fix use after free and mem leak in psb_intel_lvds_init() Jesper Juhl
@ 2012-01-17 10:15 ` Patrik Jakobsson
2012-01-17 23:20 ` Jesper Juhl
0 siblings, 1 reply; 5+ messages in thread
From: Patrik Jakobsson @ 2012-01-17 10:15 UTC (permalink / raw)
To: Jesper Juhl; +Cc: linux-kernel, dri-devel, Alan Cox
On Sat, Jan 14, 2012 at 10:15 PM, Jesper Juhl wrote:
> In psb_intel_lvds_init(), if we fail to allocate memory for
> 'psb_intel_connector' we free the memory we previously allocated for
> 'psb_intel_encoder', but we then proceed to use that free'd pointer
> when we do 'psb_intel_encoder->dev_priv = lvds_priv;'.
>
> We may also leak the memory we allocated for 'psb_intel_encoder' if we
> 'goto failed_connector;' and the variable goes out of scope.
>
> While I was there anyway, I also removed the pointless 'if
> (psb_intel_connector)' before freeing it at the 'failed_connector:'
> label - kfree() deals gracefully with NULL pointers, so it is not
> needed.
My bad, thanks for fixing
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] intel, gma500, lvds: Fix use after free and mem leak in psb_intel_lvds_init()
2012-01-17 10:15 ` Patrik Jakobsson
@ 2012-01-17 23:20 ` Jesper Juhl
0 siblings, 0 replies; 5+ messages in thread
From: Jesper Juhl @ 2012-01-17 23:20 UTC (permalink / raw)
To: Patrik Jakobsson; +Cc: linux-kernel, dri-devel, Alan Cox
On Tue, 17 Jan 2012, Patrik Jakobsson wrote:
> On Sat, Jan 14, 2012 at 10:15 PM, Jesper Juhl wrote:
> > In psb_intel_lvds_init(), if we fail to allocate memory for
> > 'psb_intel_connector' we free the memory we previously allocated for
> > 'psb_intel_encoder', but we then proceed to use that free'd pointer
> > when we do 'psb_intel_encoder->dev_priv = lvds_priv;'.
> >
> > We may also leak the memory we allocated for 'psb_intel_encoder' if we
> > 'goto failed_connector;' and the variable goes out of scope.
> >
> > While I was there anyway, I also removed the pointless 'if
> > (psb_intel_connector)' before freeing it at the 'failed_connector:'
> > label - kfree() deals gracefully with NULL pointers, so it is not
> > needed.
>
> My bad, thanks for fixing
No problem :-) Now I just hope that it will get merged :-)
--
Jesper Juhl <jj@chaosbits.net> http://www.chaosbits.net/
Don't top-post http://www.catb.org/jargon/html/T/top-post.html
Plain text mails only, please.
^ permalink raw reply [flat|nested] 5+ messages in thread
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2012-01-14 19:59 [PATCH] intel, gma500, lvds: Fix use after free on psb_intel_lvds_init() Jesper Juhl
2012-01-14 20:58 ` Jesper Juhl
2012-01-14 21:15 ` [PATCH] intel, gma500, lvds: Fix use after free and mem leak in psb_intel_lvds_init() Jesper Juhl
2012-01-17 10:15 ` Patrik Jakobsson
2012-01-17 23:20 ` Jesper Juhl
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