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drm: fix a memleak on mutex failure path

PATCH Applied [email protected] 3 participants 3 messages Apr 27, 2015 – May 5, 2015

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#0 lore raw

PATCH v2 1/1 drm: fix a memleak on mutex failure path

From: Oleg Drokin <[email protected]>

Need to free just allocated ctx allocation if we cannot get our config mutex.

This one has been flagged by kbuild bot all the way back in August, but somehow nobody picked it up:
https://lists.01.org/pipermail/kbuild/2014-August/001691.html

In addition there is another failure path that leaks the same ctx reference that is fixed.

Found with smatch.

Signed-off-by Oleg Drokin <[email protected]>
CC Daniel Vetter <[email protected]>
---
 drivers/gpu/drm/drm_modeset_lock.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)
drivers/gpu/drm/drm_modeset_lock.c +6 -2
index 51cc47d..c0a5cd8 100644
@@ -80,8 +80,10 @@ int __drm_modeset_lock_all(struct drm_device *dev,
 		return -ENOMEM;
 
 	if (trylock) {
-		if (!mutex_trylock(&config->mutex))
-			return -EBUSY;
+		if (!mutex_trylock(&config->mutex)) {
+			ret = -EBUSY;
+			goto out;
+		}
 	} else {
 		mutex_lock(&config->mutex);
 	}

@@ -114,6 +116,8 @@ fail:
 		goto retry;
 	}
 
+out:
+	kfree(ctx);
 	return ret;
 }
 EXPORT_SYMBOL(__drm_modeset_lock_all);
Signature · 1 line
2.1.0
Reviewed-by on v2 1/1
#1 lore raw
Quoted 9 lines · On Mon, 27 Apr 2015, [email protected] wrote:

From: Oleg Drokin <[email protected]>

Need to free just allocated ctx allocation if we cannot get our config mutex.

This one has been flagged by kbuild bot all the way back in August, but somehow nobody picked it up:
https://lists.01.org/pipermail/kbuild/2014-August/001691.html

Quoted 7 lines

In addition there is another failure path that leaks the same ctx reference that is fixed.

Found with smatch.

Signed-off-by Oleg Drokin <[email protected]>
CC Daniel Vetter <[email protected]>
Reviewed-by Jani Nikula <[email protected]>
Quoted 33 lines
---
 drivers/gpu/drm/drm_modeset_lock.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)
drivers/gpu/drm/drm_modeset_lock.c +6 -2
index 51cc47d..c0a5cd8 100644
@@ -80,8 +80,10 @@ int __drm_modeset_lock_all(struct drm_device *dev,
 		return -ENOMEM;
 
 	if (trylock) {
-		if (!mutex_trylock(&config->mutex))
-			return -EBUSY;
+		if (!mutex_trylock(&config->mutex)) {
+			ret = -EBUSY;
+			goto out;
+		}
 	} else {
 		mutex_lock(&config->mutex);
 	}

@@ -114,6 +116,8 @@ fail:
 		goto retry;
 	}
 
+out:
+	kfree(ctx);
 	return ret;
 }
 EXPORT_SYMBOL(__drm_modeset_lock_all);
Signature · 1 line
2.1.0
Signature · 1 line
Jani Nikula, Intel Open Source Technology Center
Applied
#2 lore raw
Quoted 13 lines · Jani Nikula
Quoted 12 lines · On Mon, 27 Apr 2015, [email protected] wrote:

From: Oleg Drokin <[email protected]>

Need to free just allocated ctx allocation if we cannot get our config mutex.

This one has been flagged by kbuild bot all the way back in August, but somehow nobody picked it up:
https://lists.01.org/pipermail/kbuild/2014-August/001691.html

In addition there is another failure path that leaks the same ctx reference that is fixed.

Quoted 6 lines
Quoted 4 lines

Found with smatch.

Signed-off-by Oleg Drokin <[email protected]>
CC Daniel Vetter <[email protected]>
Reviewed-by Jani Nikula <[email protected]>

Applied to topic/drm-misc, thanks.
-Daniel

Signature · 7 lines
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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