From: Chuck Lever Date: Wed, 31 Mar 2021 17:22:14 +0000 (-0400) Subject: SUNRPC: Move fault injection call sites X-Git-Tag: v5.10.38~167 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=7b906077fd990b1888a5bd49ffb1782077ca6509;p=thirdparty%2Fkernel%2Fstable.git SUNRPC: Move fault injection call sites [ Upstream commit 7638e0bfaed1b653d3ca663e560e9ffb44bb1030 ] I've hit some crashes that occur in the xprt_rdma_inject_disconnect path. It appears that, for some provides, rdma_disconnect() can take so long that the transport can disconnect and release its hardware resources while rdma_disconnect() is still running, resulting in a UAF in the provider. The transport's fault injection method may depend on the stability of transport data structures. That means it needs to be invoked only from contexts that hold the transport write lock. Fixes: 4a0682583988 ("SUNRPC: Transport fault injection") Signed-off-by: Chuck Lever Signed-off-by: Trond Myklebust Signed-off-by: Sasha Levin --- diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c index 3259120462ed7..69d8843a26e07 100644 --- a/net/sunrpc/clnt.c +++ b/net/sunrpc/clnt.c @@ -1802,7 +1802,6 @@ call_allocate(struct rpc_task *task) status = xprt->ops->buf_alloc(task); trace_rpc_buf_alloc(task, status); - xprt_inject_disconnect(xprt); if (status == 0) return; if (status != -ENOMEM) { diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c index 57f09ea3ef2af..99d07513237e0 100644 --- a/net/sunrpc/xprt.c +++ b/net/sunrpc/xprt.c @@ -1455,7 +1455,10 @@ bool xprt_prepare_transmit(struct rpc_task *task) void xprt_end_transmit(struct rpc_task *task) { - xprt_release_write(task->tk_rqstp->rq_xprt, task); + struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt; + + xprt_inject_disconnect(xprt); + xprt_release_write(xprt, task); } /** @@ -1857,7 +1860,6 @@ void xprt_release(struct rpc_task *task) spin_unlock(&xprt->transport_lock); if (req->rq_buffer) xprt->ops->buf_free(task); - xprt_inject_disconnect(xprt); xdr_free_bvec(&req->rq_rcv_buf); xdr_free_bvec(&req->rq_snd_buf); if (req->rq_cred != NULL) diff --git a/net/sunrpc/xprtrdma/transport.c b/net/sunrpc/xprtrdma/transport.c index 035060c05fd5a..f93ff4282bf4f 100644 --- a/net/sunrpc/xprtrdma/transport.c +++ b/net/sunrpc/xprtrdma/transport.c @@ -262,8 +262,10 @@ xprt_rdma_connect_worker(struct work_struct *work) * xprt_rdma_inject_disconnect - inject a connection fault * @xprt: transport context * - * If @xprt is connected, disconnect it to simulate spurious connection - * loss. + * If @xprt is connected, disconnect it to simulate spurious + * connection loss. Caller must hold @xprt's send lock to + * ensure that data structures and hardware resources are + * stable during the rdma_disconnect() call. */ static void xprt_rdma_inject_disconnect(struct rpc_xprt *xprt)