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authorJulia Lawall <julia@diku.dk>2011-07-09 21:23:26 +0200
committerGreg Kroah-Hartman <gregkh@suse.de>2011-08-02 16:12:49 -0700
commitfe3e593601752d547bd00d83f0bdedbce1d80f59 (patch)
tree153f35363ec1c74c545345398876ea7f3a75d233
parent55dc6ee7def173f0dd3b6d0d0257917112d542e9 (diff)
downloadblackbird-op-linux-fe3e593601752d547bd00d83f0bdedbce1d80f59.tar.gz
blackbird-op-linux-fe3e593601752d547bd00d83f0bdedbce1d80f59.zip
drivers/staging/hv/blkvsc_drv.c: eliminate NULL pointer dereference
In this code, blkvsc_req is allocated in the cache blkdev->request_pool, but freed in the first case to the cache blkvsc_req->dev->request_pool. blkvsc_req->dev is subsequently initialized to blkdev, making these the same at the second call to kmem_cache_free. But at the point of the first call, blkvsc_req->dev is NULL. The second call is changed too, for uniformity. The semantic patch that fixes this problem is as follows: (http://coccinelle.lip6.fr/) // <smpl> @@ expression x,e,e1,e2,e3; @@ x = \(kmem_cache_alloc\|kmem_cache_zalloc\)(e1,e2) ... when != x = e ( kmem_cache_free(e1,x); | ?-kmem_cache_free(e3,x); +kmem_cache_free(e1,x); ) // </smpl> Signed-off-by: Julia Lawall <julia@diku.dk> Cc: KY Srinivasan <kys@microsoft.com> Cc: Hank Janssen <hjanssen@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
-rw-r--r--drivers/staging/hv/blkvsc_drv.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/staging/hv/blkvsc_drv.c b/drivers/staging/hv/blkvsc_drv.c
index 3612574ca520..d286b2223181 100644
--- a/drivers/staging/hv/blkvsc_drv.c
+++ b/drivers/staging/hv/blkvsc_drv.c
@@ -325,7 +325,7 @@ static int blkvsc_do_operation(struct block_device_context *blkdev,
page_buf = alloc_page(GFP_KERNEL);
if (!page_buf) {
- kmem_cache_free(blkvsc_req->dev->request_pool, blkvsc_req);
+ kmem_cache_free(blkdev->request_pool, blkvsc_req);
return -ENOMEM;
}
@@ -422,7 +422,7 @@ cleanup:
__free_page(page_buf);
- kmem_cache_free(blkvsc_req->dev->request_pool, blkvsc_req);
+ kmem_cache_free(blkdev->request_pool, blkvsc_req);
return ret;
}
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