[PATCH 4.11 019/115] smc: switch to usage of IB_PD_UNSAFE_GLOBAL_RKEY

Greg Kroah-Hartman
2017-06-05T16:29:21Z

From: Ursula Braun <ubraun@linux.vnet.ibm.com>

[ Upstream commit 263eec9b2a82e8697d064709414914b5b10ac538 ]

Currently, SMC enables remote access to physical memory when a user
has successfully configured and established an SMC-connection until ten
minutes after the last SMC connection is closed. Because this is considered
a security risk, drivers are supposed to use IB_PD_UNSAFE_GLOBAL_RKEY in
such a case.

This patch changes the current SMC code to use IB_PD_UNSAFE_GLOBAL_RKEY.
This improves user awareness, but does not remove the security risk itself.

Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/smc/smc_clc.c | 4 ++--
net/smc/smc_core.c | 16 +++-------------
net/smc/smc_core.h | 2 +-
net/smc/smc_ib.c | 21 ++-------------------
net/smc/smc_ib.h | 2 --
5 files changed, 8 insertions(+), 37 deletions(-)

--- a/net/smc/smc_clc.c
+++ b/net/smc/smc_clc.c
@@ -204,7 +204,7 @@ int smc_clc_send_confirm(struct smc_sock
memcpy(&cclc.lcl.mac, &link->smcibdev->mac[link->ibport - 1], ETH_ALEN);
hton24(cclc.qpn, link->roce_qp->qp_num);
cclc.rmb_rkey =
- htonl(conn->rmb_desc->mr_rx[SMC_SINGLE_LINK]->rkey);
+ htonl(conn->rmb_desc->rkey[SMC_SINGLE_LINK]);
cclc.conn_idx = 1; /* for now: 1 RMB = 1 RMBE */
cclc.rmbe_alert_token = htonl(conn->alert_token_local);
cclc.qp_mtu = min(link->path_mtu, link->peer_mtu);
@@ -256,7 +256,7 @@ int smc_clc_send_accept(struct smc_sock
memcpy(&aclc.lcl.mac, link->smcibdev->mac[link->ibport - 1], ETH_ALEN);
hton24(aclc.qpn, link->roce_qp->qp_num);
aclc.rmb_rkey =
- htonl(conn->rmb_desc->mr_rx[SMC_SINGLE_LINK]->rkey);
+ htonl(conn->rmb_desc->rkey[SMC_SINGLE_LINK]);
aclc.conn_idx = 1; /* as long as 1 RMB = 1 RMBE */
aclc.rmbe_alert_token = htonl(conn->alert_token_local);
aclc.qp_mtu = link->path_mtu;
--- a/net/smc/smc_core.c
+++ b/net/smc/smc_core.c
@@ -613,19 +613,8 @@ int smc_rmb_create(struct smc_sock *smc)
rmb_desc = NULL;
continue; /* if mapping failed, try smaller one */
}
- rc = smc_ib_get_memory_region(lgr->lnk[SMC_SINGLE_LINK].roce_pd,
- IB_ACCESS_REMOTE_WRITE |
- IB_ACCESS_LOCAL_WRITE,
- &rmb_desc->mr_rx[SMC_SINGLE_LINK]);
- if (rc) {
- smc_ib_buf_unmap(lgr->lnk[SMC_SINGLE_LINK].smcibdev,
- tmp_bufsize, rmb_desc,
- DMA_FROM_DEVICE);
- kfree(rmb_desc->cpu_addr);
- kfree(rmb_desc);
- rmb_desc = NULL;
- continue;
- }
+ rmb_desc->rkey[SMC_SINGLE_LINK] =
+ lgr->lnk[SMC_SINGLE_LINK].roce_pd->unsafe_global_rkey;
rmb_desc->used = 1;
write_lock_bh(&lgr->rmbs_lock);
list_add(&rmb_desc->list,
@@ -668,6 +657,7 @@ int smc_rmb_rtoken_handling(struct smc_c

for (i = 0; i < SMC_RMBS_PER_LGR_MAX; i++) {
if ((lgr->rtokens[i][SMC_SINGLE_LINK].rkey == rkey) &&
+ (lgr->rtokens[i][SMC_SINGLE_LINK].dma_addr == dma_addr) &&
test_bit(i, lgr->rtokens_used_mask)) {
conn->rtoken_idx = i;
return 0;
--- a/net/smc/smc_core.h
+++ b/net/smc/smc_core.h
@@ -93,7 +93,7 @@ struct smc_buf_desc {
u64 dma_addr[SMC_LINKS_PER_LGR_MAX];
/* mapped address of buffer */
void *cpu_addr; /* virtual address of buffer */
- struct ib_mr *mr_rx[SMC_LINKS_PER_LGR_MAX];
+ u32 rkey[SMC_LINKS_PER_LGR_MAX];
/* for rmb only:
* rkey provided to peer
*/
--- a/net/smc/smc_ib.c
+++ b/net/smc/smc_ib.c
@@ -37,24 +37,6 @@ u8 local_systemid[SMC_SYSTEMID_LEN] = SM
* identifier
*/

-int smc_ib_get_memory_region(struct ib_pd *pd, int access_flags,
- struct ib_mr **mr)
-{
- int rc;
-
- if (*mr)
- return 0; /* already done */
-
- /* obtain unique key -
- * next invocation of get_dma_mr returns a different key!
- */
- *mr = pd->device->get_dma_mr(pd, access_flags);
- rc = PTR_ERR_OR_ZERO(*mr);
- if (IS_ERR(*mr))
- *mr = NULL;
- return rc;
-}
-
static int smc_ib_modify_qp_init(struct smc_link *lnk)
{
struct ib_qp_attr qp_attr;
@@ -213,7 +195,8 @@ int smc_ib_create_protection_domain(stru
{
int rc;

- lnk->roce_pd = ib_alloc_pd(lnk->smcibdev->ibdev, 0);
+ lnk->roce_pd = ib_alloc_pd(lnk->smcibdev->ibdev,
+ IB_PD_UNSAFE_GLOBAL_RKEY);
rc = PTR_ERR_OR_ZERO(lnk->roce_pd);
if (IS_ERR(lnk->roce_pd))
lnk->roce_pd = NULL;
--- a/net/smc/smc_ib.h
+++ b/net/smc/smc_ib.h
@@ -60,8 +60,6 @@ void smc_ib_dealloc_protection_domain(st
int smc_ib_create_protection_domain(struct smc_link *lnk);
void smc_ib_destroy_queue_pair(struct smc_link *lnk);
int smc_ib_create_queue_pair(struct smc_link *lnk);
-int smc_ib_get_memory_region(struct ib_pd *pd, int access_flags,
- struct ib_mr **mr);
int smc_ib_ready_link(struct smc_link *lnk);
int smc_ib_modify_qp_rts(struct smc_link *lnk);
int smc_ib_modify_qp_reset(struct smc_link *lnk);