linux/net/sunrpc/bc_svc.c
Trond Myklebust c9acb42ef1 SUNRPC: Fix a use after free bug with the NFSv4.1 backchannel
The ->release_request() callback was designed to allow the transport layer
to do housekeeping after the RPC call is done. It cannot be used to free
the request itself, and doing so leads to a use-after-free bug in
xprt_release().

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-03-22 05:32:44 -04:00

67 lines
2.0 KiB
C

/******************************************************************************
(c) 2007 Network Appliance, Inc. All Rights Reserved.
(c) 2009 NetApp. All Rights Reserved.
NetApp provides this source code under the GPL v2 License.
The GPL v2 license is available at
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"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
******************************************************************************/
/*
* The NFSv4.1 callback service helper routines.
* They implement the transport level processing required to send the
* reply over an existing open connection previously established by the client.
*/
#if defined(CONFIG_NFS_V4_1)
#include <linux/module.h>
#include <linux/sunrpc/xprt.h>
#include <linux/sunrpc/sched.h>
#include <linux/sunrpc/bc_xprt.h>
#define RPCDBG_FACILITY RPCDBG_SVCDSP
/* Empty callback ops */
static const struct rpc_call_ops nfs41_callback_ops = {
};
/*
* Send the callback reply
*/
int bc_send(struct rpc_rqst *req)
{
struct rpc_task *task;
int ret;
dprintk("RPC: bc_send req= %p\n", req);
task = rpc_run_bc_task(req, &nfs41_callback_ops);
if (IS_ERR(task))
ret = PTR_ERR(task);
else {
BUG_ON(atomic_read(&task->tk_count) != 1);
ret = task->tk_status;
rpc_put_task(task);
}
return ret;
dprintk("RPC: bc_send ret= %d \n", ret);
}
#endif /* CONFIG_NFS_V4_1 */