staging: lustre: ko2iblnd: check copy_from_iter/copy_to_iter return code

commit 566e1ce22e04426fa52328b2adcdf1df49acd98e upstream.

We now get a helpful warning for code that calls copy_{from,to}_iter
without checking the return value, introduced by commit aa28de275a24
("iov_iter/hardening: move object size checks to inlined part").

drivers/staging/lustre/lnet/klnds/o2iblnd/o2iblnd_cb.c: In function 'kiblnd_send':
drivers/staging/lustre/lnet/klnds/o2iblnd/o2iblnd_cb.c:1643:2: error: ignoring return value of 'copy_from_iter', declared with attribute warn_unused_result [-Werror=unused-result]
drivers/staging/lustre/lnet/klnds/o2iblnd/o2iblnd_cb.c: In function 'kiblnd_recv':
drivers/staging/lustre/lnet/klnds/o2iblnd/o2iblnd_cb.c:1744:3: error: ignoring return value of 'copy_to_iter', declared with attribute warn_unused_result [-Werror=unused-result]

In case we get short copies here, we may get incorrect behavior.
I've added failure handling for both rx and tx now, returning
-EFAULT as expected.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/lustre/lnet/klnds/o2iblnd/o2iblnd_cb.c b/drivers/staging/lustre/lnet/klnds/o2iblnd/o2iblnd_cb.c
index b27de88..995f2da 100644 (file)
--- a/drivers/staging/lustre/lnet/klnds/o2iblnd/o2iblnd_cb.c
+++ b/drivers/staging/lustre/lnet/klnds/o2iblnd/o2iblnd_cb.c
@@ -1650,8 +1650,13 @@ kiblnd_send(lnet_ni_t *ni, void *private, lnet_msg_t *lntmsg)
        ibmsg = tx->tx_msg;
        ibmsg->ibm_u.immediate.ibim_hdr = *hdr;
 
-       copy_from_iter(&ibmsg->ibm_u.immediate.ibim_payload, IBLND_MSG_SIZE,
-                      &from);
+       rc = copy_from_iter(&ibmsg->ibm_u.immediate.ibim_payload, payload_nob,
+                           &from);
+       if (rc != payload_nob) {
+               kiblnd_pool_free_node(&tx->tx_pool->tpo_pool, &tx->tx_list);
+               return -EFAULT;
+       }
+
        nob = offsetof(struct kib_immediate_msg, ibim_payload[payload_nob]);
        kiblnd_init_tx_msg(ni, tx, IBLND_MSG_IMMEDIATE, nob);
 
@@ -1751,8 +1756,14 @@ kiblnd_recv(lnet_ni_t *ni, void *private, lnet_msg_t *lntmsg, int delayed,
                        break;
                }
 
-               copy_to_iter(&rxmsg->ibm_u.immediate.ibim_payload,
-                            IBLND_MSG_SIZE, to);
+               rc = copy_to_iter(&rxmsg->ibm_u.immediate.ibim_payload, rlen,
+                                 to);
+               if (rc != rlen) {
+                       rc = -EFAULT;
+                       break;
+               }
+
+               rc = 0;
                lnet_finalize(ni, lntmsg, 0);
                break;