From 2dc3a69de0d6e7f4dba7dbf8eadd5c3ac34098c7 Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Wed, 29 Jun 2016 13:53:11 -0400 Subject: [PATCH] xprtrdma: Remove ALLPHYSICAL memory registration mode No HCA or RNIC in the kernel tree requires the use of ALLPHYSICAL. ALLPHYSICAL advertises in the clear on the network fabric an R_key that is good for all of the client's memory. No known exploit exists, but theoretically any user on the server can use that R_key on the client's QP to read or update any part of the client's memory. ALLPHYSICAL exposes the client to server bugs, including: o base/bounds errors causing data outside the i/o buffer to be accessed o RDMA access after reply causing data corruption and/or integrity fail ALLPHYSICAL can't protect application memory regions from server update after a local signal or soft timeout has terminated an RPC. ALLPHYSICAL chunks are no larger than a page. Special cases to handle small chunks and long chunk lists have been a source of implementation complexity and bugs. Signed-off-by: Chuck Lever Tested-by: Steve Wise Signed-off-by: Anna Schumaker --- net/sunrpc/xprtrdma/Makefile | 2 +- net/sunrpc/xprtrdma/physical_ops.c | 122 ----------------------------- net/sunrpc/xprtrdma/verbs.c | 15 ---- net/sunrpc/xprtrdma/xprt_rdma.h | 5 +- 4 files changed, 2 insertions(+), 142 deletions(-) delete mode 100644 net/sunrpc/xprtrdma/physical_ops.c diff --git a/net/sunrpc/xprtrdma/Makefile b/net/sunrpc/xprtrdma/Makefile index dc9f3b513a05..ef19fa42c50f 100644 --- a/net/sunrpc/xprtrdma/Makefile +++ b/net/sunrpc/xprtrdma/Makefile @@ -1,7 +1,7 @@ obj-$(CONFIG_SUNRPC_XPRT_RDMA) += rpcrdma.o rpcrdma-y := transport.o rpc_rdma.o verbs.o \ - fmr_ops.o frwr_ops.o physical_ops.o \ + fmr_ops.o frwr_ops.o \ svc_rdma.o svc_rdma_backchannel.o svc_rdma_transport.o \ svc_rdma_marshal.o svc_rdma_sendto.o svc_rdma_recvfrom.o \ module.o diff --git a/net/sunrpc/xprtrdma/physical_ops.c b/net/sunrpc/xprtrdma/physical_ops.c deleted file mode 100644 index 3750596cc432..000000000000 --- a/net/sunrpc/xprtrdma/physical_ops.c +++ /dev/null @@ -1,122 +0,0 @@ -/* - * Copyright (c) 2015 Oracle. All rights reserved. - * Copyright (c) 2003-2007 Network Appliance, Inc. All rights reserved. - */ - -/* No-op chunk preparation. All client memory is pre-registered. - * Sometimes referred to as ALLPHYSICAL mode. - * - * Physical registration is simple because all client memory is - * pre-registered and never deregistered. This mode is good for - * adapter bring up, but is considered not safe: the server is - * trusted not to abuse its access to client memory not involved - * in RDMA I/O. - */ - -#include "xprt_rdma.h" - -#if IS_ENABLED(CONFIG_SUNRPC_DEBUG) -# define RPCDBG_FACILITY RPCDBG_TRANS -#endif - -static int -physical_op_open(struct rpcrdma_ia *ia, struct rpcrdma_ep *ep, - struct rpcrdma_create_data_internal *cdata) -{ - struct ib_mr *mr; - - /* Obtain an rkey to use for RPC data payloads. - */ - mr = ib_get_dma_mr(ia->ri_pd, - IB_ACCESS_LOCAL_WRITE | - IB_ACCESS_REMOTE_WRITE | - IB_ACCESS_REMOTE_READ); - if (IS_ERR(mr)) { - pr_err("%s: ib_get_dma_mr for failed with %lX\n", - __func__, PTR_ERR(mr)); - return -ENOMEM; - } - ia->ri_dma_mr = mr; - - rpcrdma_set_max_header_sizes(ia, cdata, min_t(unsigned int, - RPCRDMA_MAX_DATA_SEGS, - RPCRDMA_MAX_HDR_SEGS)); - return 0; -} - -/* PHYSICAL memory registration conveys one page per chunk segment. - */ -static size_t -physical_op_maxpages(struct rpcrdma_xprt *r_xprt) -{ - return min_t(unsigned int, RPCRDMA_MAX_DATA_SEGS, - RPCRDMA_MAX_HDR_SEGS); -} - -static int -physical_op_init(struct rpcrdma_xprt *r_xprt) -{ - return 0; -} - -/* The client's physical memory is already exposed for - * remote access via RDMA READ or RDMA WRITE. - */ -static int -physical_op_map(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg, - int nsegs, bool writing) -{ - struct rpcrdma_ia *ia = &r_xprt->rx_ia; - - rpcrdma_map_one(ia->ri_device, seg, rpcrdma_data_dir(writing)); - seg->mr_rkey = ia->ri_dma_mr->rkey; - seg->mr_base = seg->mr_dma; - return 1; -} - -/* DMA unmap all memory regions that were mapped for "req". - */ -static void -physical_op_unmap_sync(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req) -{ - struct ib_device *device = r_xprt->rx_ia.ri_device; - unsigned int i; - - for (i = 0; req->rl_nchunks; --req->rl_nchunks) - rpcrdma_unmap_one(device, &req->rl_segments[i++]); -} - -/* Use a slow, safe mechanism to invalidate all memory regions - * that were registered for "req". - * - * For physical memory registration, there is no good way to - * fence a single MR that has been advertised to the server. The - * client has already handed the server an R_key that cannot be - * invalidated and is shared by all MRs on this connection. - * Tearing down the PD might be the only safe choice, but it's - * not clear that a freshly acquired DMA R_key would be different - * than the one used by the PD that was just destroyed. - * FIXME. - */ -static void -physical_op_unmap_safe(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req, - bool sync) -{ - physical_op_unmap_sync(r_xprt, req); -} - -static void -physical_op_destroy(struct rpcrdma_buffer *buf) -{ -} - -const struct rpcrdma_memreg_ops rpcrdma_physical_memreg_ops = { - .ro_map = physical_op_map, - .ro_unmap_sync = physical_op_unmap_sync, - .ro_unmap_safe = physical_op_unmap_safe, - .ro_open = physical_op_open, - .ro_maxpages = physical_op_maxpages, - .ro_init = physical_op_init, - .ro_destroy = physical_op_destroy, - .ro_displayname = "physical", -}; diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c index 77a371d3cde8..5ee98e9d0fe9 100644 --- a/net/sunrpc/xprtrdma/verbs.c +++ b/net/sunrpc/xprtrdma/verbs.c @@ -379,8 +379,6 @@ rpcrdma_ia_open(struct rpcrdma_xprt *xprt, struct sockaddr *addr, int memreg) struct rpcrdma_ia *ia = &xprt->rx_ia; int rc; - ia->ri_dma_mr = NULL; - ia->ri_id = rpcrdma_create_id(xprt, ia, addr); if (IS_ERR(ia->ri_id)) { rc = PTR_ERR(ia->ri_id); @@ -418,9 +416,6 @@ rpcrdma_ia_open(struct rpcrdma_xprt *xprt, struct sockaddr *addr, int memreg) case RPCRDMA_FRMR: ia->ri_ops = &rpcrdma_frwr_memreg_ops; break; - case RPCRDMA_ALLPHYSICAL: - ia->ri_ops = &rpcrdma_physical_memreg_ops; - break; case RPCRDMA_MTHCAFMR: ia->ri_ops = &rpcrdma_fmr_memreg_ops; break; @@ -585,8 +580,6 @@ rpcrdma_ep_create(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia, out2: ib_free_cq(sendcq); out1: - if (ia->ri_dma_mr) - ib_dereg_mr(ia->ri_dma_mr); return rc; } @@ -600,8 +593,6 @@ out1: void rpcrdma_ep_destroy(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia) { - int rc; - dprintk("RPC: %s: entering, connected is %d\n", __func__, ep->rep_connected); @@ -615,12 +606,6 @@ rpcrdma_ep_destroy(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia) ib_free_cq(ep->rep_attr.recv_cq); ib_free_cq(ep->rep_attr.send_cq); - - if (ia->ri_dma_mr) { - rc = ib_dereg_mr(ia->ri_dma_mr); - dprintk("RPC: %s: ib_dereg_mr returned %i\n", - __func__, rc); - } } /* diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h index 4e03037d042c..bcb168e3fe15 100644 --- a/net/sunrpc/xprtrdma/xprt_rdma.h +++ b/net/sunrpc/xprtrdma/xprt_rdma.h @@ -68,7 +68,6 @@ struct rpcrdma_ia { struct ib_device *ri_device; struct rdma_cm_id *ri_id; struct ib_pd *ri_pd; - struct ib_mr *ri_dma_mr; struct completion ri_done; int ri_async_rc; unsigned int ri_max_frmr_depth; @@ -269,8 +268,7 @@ struct rpcrdma_mw { * NOTES: * o RPCRDMA_MAX_SEGS is the max number of addressible chunk elements we * marshal. The number needed varies depending on the iov lists that - * are passed to us, the memory registration mode we are in, and if - * physical addressing is used, the layout. + * are passed to us and the memory registration mode we are in. */ struct rpcrdma_mr_seg { /* chunk descriptors */ @@ -417,7 +415,6 @@ struct rpcrdma_memreg_ops { extern const struct rpcrdma_memreg_ops rpcrdma_fmr_memreg_ops; extern const struct rpcrdma_memreg_ops rpcrdma_frwr_memreg_ops; -extern const struct rpcrdma_memreg_ops rpcrdma_physical_memreg_ops; /* * RPCRDMA transport -- encapsulates the structures above for -- 2.20.1