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From: Xi Wang <xi.wang@gmail.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: [PATCH v2] mm: fix null dev in dma_pool_create()
Date: Tue, 13 Nov 2012 16:39:37 -0500	[thread overview]
Message-ID: <50A2BE19.7000604@gmail.com> (raw)
In-Reply-To: <1352097996-25808-1-git-send-email-xi.wang@gmail.com>

A few drivers invoke dma_pool_create() with a null dev.  Note that dev
is dereferenced in dev_to_node(dev), causing a null pointer dereference.

A long term solution is to disallow null dev.  Once the drivers are
fixed, we can simplify the core code here.  For now we add WARN_ON(!dev)
to notify the driver maintainers and avoid the null pointer dereference.

Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Xi Wang <xi.wang@gmail.com>
---
 mm/dmapool.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/mm/dmapool.c b/mm/dmapool.c
index c5ab33b..bf7f8f0 100644
--- a/mm/dmapool.c
+++ b/mm/dmapool.c
@@ -135,6 +135,7 @@ struct dma_pool *dma_pool_create(const char *name, struct device *dev,
 {
 	struct dma_pool *retval;
 	size_t allocation;
+	int node;
 
 	if (align == 0) {
 		align = 1;
@@ -159,7 +160,9 @@ struct dma_pool *dma_pool_create(const char *name, struct device *dev,
 		return NULL;
 	}
 
-	retval = kmalloc_node(sizeof(*retval), GFP_KERNEL, dev_to_node(dev));
+	node = WARN_ON(!dev) ? -1 : dev_to_node(dev);
+
+	retval = kmalloc_node(sizeof(*retval), GFP_KERNEL, node);
 	if (!retval)
 		return retval;
 
-- 
1.7.10.4


WARNING: multiple messages have this Message-ID (diff)
From: Xi Wang <xi.wang@gmail.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: [PATCH v2] mm: fix null dev in dma_pool_create()
Date: Tue, 13 Nov 2012 16:39:37 -0500	[thread overview]
Message-ID: <50A2BE19.7000604@gmail.com> (raw)
In-Reply-To: <1352097996-25808-1-git-send-email-xi.wang@gmail.com>

A few drivers invoke dma_pool_create() with a null dev.  Note that dev
is dereferenced in dev_to_node(dev), causing a null pointer dereference.

A long term solution is to disallow null dev.  Once the drivers are
fixed, we can simplify the core code here.  For now we add WARN_ON(!dev)
to notify the driver maintainers and avoid the null pointer dereference.

Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Xi Wang <xi.wang@gmail.com>
---
 mm/dmapool.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/mm/dmapool.c b/mm/dmapool.c
index c5ab33b..bf7f8f0 100644
--- a/mm/dmapool.c
+++ b/mm/dmapool.c
@@ -135,6 +135,7 @@ struct dma_pool *dma_pool_create(const char *name, struct device *dev,
 {
 	struct dma_pool *retval;
 	size_t allocation;
+	int node;
 
 	if (align == 0) {
 		align = 1;
@@ -159,7 +160,9 @@ struct dma_pool *dma_pool_create(const char *name, struct device *dev,
 		return NULL;
 	}
 
-	retval = kmalloc_node(sizeof(*retval), GFP_KERNEL, dev_to_node(dev));
+	node = WARN_ON(!dev) ? -1 : dev_to_node(dev);
+
+	retval = kmalloc_node(sizeof(*retval), GFP_KERNEL, node);
 	if (!retval)
 		return retval;
 
-- 
1.7.10.4

--
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  parent reply	other threads:[~2012-11-13 21:39 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-11-05  6:46 [PATCH] mm: fix NULL checking in dma_pool_create() Xi Wang
2012-11-05  6:46 ` Xi Wang
2012-11-05 20:37 ` Andrew Morton
2012-11-05 20:37   ` Andrew Morton
2012-11-05 20:50   ` Xi Wang
2012-11-05 20:50     ` Xi Wang
2012-11-05 21:26     ` Andrew Morton
2012-11-05 21:26       ` Andrew Morton
2012-11-06 20:48       ` Xi Wang
2012-11-06 20:48         ` Xi Wang
2012-11-13 21:39 ` Xi Wang [this message]
2012-11-13 21:39   ` [PATCH v2] mm: fix null dev " Xi Wang
2012-11-13 23:01   ` David Rientjes
2012-11-13 23:01     ` David Rientjes
2012-11-14  0:47     ` Andrew Morton
2012-11-14  0:47       ` Andrew Morton
2012-11-14  0:58   ` Andrew Morton
2012-11-14  0:58     ` Andrew Morton
2012-11-14  5:50     ` Xi Wang
2012-11-14  5:50       ` Xi Wang
2012-11-14 14:17       ` Felipe Balbi
2012-11-14 14:17         ` Felipe Balbi

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