From: Julia Lawall <julia@diku.dk>
Date: Sat, 9 Jul 2011 19:23:26 +0000 (+0200)
Subject: drivers/staging/hv/blkvsc_drv.c: eliminate NULL pointer dereference
X-Git-Tag: v3.1-rc2~15^2~5
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=fe3e593601752d547bd00d83f0bdedbce1d80f59;p=pandora-kernel.git

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>
---

Reading git-diff-tree failed