The changes look good to me. -----Original Message----- From: James Simmons [mailto:jsimmons@xxxxxxxxxxxxx] Sent: Saturday, July 15, 2017 8:32 AM To: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>; devel@xxxxxxxxxxxxxxxxxxxx; Dilger, Andreas <andreas.dilger@xxxxxxxxx>; Drokin, Oleg <oleg.drokin@xxxxxxxxx>; Arnd Bergmann <arnd@xxxxxxxx>; Al Viro <viro@xxxxxxxxxxxxxxxxxx> Cc: Shehata, Amir <amir.shehata@xxxxxxxxx>; Olaf Weber <olaf.weber@xxxxxxx>; Linux Kernel Mailing List <linux-kernel@xxxxxxxxxxxxxxx>; Lustre Development List <lustre-devel@xxxxxxxxxxxxxxxx>; stable@xxxxxxxxxxxxxxx; James Simmons <jsimmons@xxxxxxxxxxxxx> Subject: [PATCH] staging: lustre: ko2iblnd: check copy_from_iter/copy_to_iter return code From: Arnd Bergmann <arnd@xxxxxxxx> 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. Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx> Signed-off-by: James Simmons <jsimmons@xxxxxxxxxxxxx> Signed-off-by: Amir Shehata <amir.shehata@xxxxxxxxx> --- .../staging/lustre/lnet/klnds/o2iblnd/o2iblnd_cb.c | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-) diff --git a/drivers/staging/lustre/lnet/klnds/o2iblnd/o2iblnd_cb.c b/drivers/staging/lustre/lnet/klnds/o2iblnd/o2iblnd_cb.c index 85b242e..8fc191d 100644 --- a/drivers/staging/lustre/lnet/klnds/o2iblnd/o2iblnd_cb.c +++ b/drivers/staging/lustre/lnet/klnds/o2iblnd/o2iblnd_cb.c @@ -1640,8 +1640,13 @@ static int kiblnd_resolve_addr(struct rdma_cm_id *cmid, 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); @@ -1741,8 +1746,14 @@ static int kiblnd_resolve_addr(struct rdma_cm_id *cmid, 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; -- 1.8.3.1