Message-Id: <20120823104725.830795272@openvz.org>
User-Agent: quilt/0.48-1
Date: Thu, 23 Aug 2012 14:43:27 +0400
From: Cyrill Gorcunov <gorcunov@openvz.org>
To: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org
Cc: Al Viro <viro@zeniv.linux.org.uk>, Alexey Dobriyan <adobriyan@gmail.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Pavel Emelyanov <xemul@parallels.com>,
        James Bottomley <jbottomley@parallels.com>,
        Matthew Helsley <matt.helsley@gmail.com>,
        aneesh.kumar@linux.vnet.ibm.com, bfields@fieldses.org,
        Cyrill Gorcunov <gorcunov@openvz.org>,
        Al Viro <viro@zeniv.linux.org.uk>
Subject: [patch 4/9] fs, exportfs: Fix nil dereference if no s_export_op present
References: <20120823104323.040550004@openvz.org>
Content-Disposition: inline; filename=fs-exportfs-add-null-check
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1449
Lines: 38

If there is no s_export_op present in a target superblock
we might have nil dereference. Fix it with eplicit test
if s_export_op is provided.

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
CC: Pavel Emelyanov <xemul@parallels.com>
CC: Al Viro <viro@ZenIV.linux.org.uk>
CC: Alexey Dobriyan <adobriyan@gmail.com>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: James Bottomley <jbottomley@parallels.com>
CC: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
CC: Alexey Dobriyan <adobriyan@gmail.com>
CC: Matthew Helsley <matt.helsley@gmail.com>
CC: "J. Bruce Fields" <bfields@fieldses.org>
CC: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
---
 fs/exportfs/expfs.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Index: linux-2.6.git/fs/exportfs/expfs.c
===================================================================
--- linux-2.6.git.orig/fs/exportfs/expfs.c
+++ linux-2.6.git/fs/exportfs/expfs.c
@@ -357,7 +357,7 @@ int exportfs_encode_fh(struct dentry *de
 		 */
 		parent = p->d_inode;
 	}
-	if (nop->encode_fh)
+	if (nop && nop->encode_fh)
 		error = nop->encode_fh(inode, fid->raw, max_len, parent);
 	else
 		error = export_encode_fh(inode, fid, max_len, parent);

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/