From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753837AbdJaKSd (ORCPT ); Tue, 31 Oct 2017 06:18:33 -0400 Received: from mx2.suse.de ([195.135.220.15]:42324 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753608AbdJaKSa (ORCPT ); Tue, 31 Oct 2017 06:18:30 -0400 From: Thomas Bogendoerfer To: Moni Shoua , Doug Ledford , linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2] IB/rxe: don't crash, if allocation of crc algorithm failed Date: Tue, 31 Oct 2017 11:16:46 +0100 Message-Id: <20171031101647.45111-1-tbogendoerfer@suse.de> X-Mailer: git-send-email 2.12.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Following crash happens, if crc algorithm couldn't be allocated: [ 1087.989072] rdma_rxe: loaded [ 1097.855397] PCLMULQDQ-NI instructions are not detected. [ 1097.901220] rdma_rxe: failed to allocate crc algorithmi err:-2 [ 1097.901248] BUG: unable to handle kernel [ 1097.901249] NULL pointer dereference [ 1097.901250] at 0000000000000046 [...] Reason is that rxe->tfm is assigned the error return, which will then be used for crypto_free_shash() in rxe_cleanup. Fix by using a temporary variable and assigning it rxe->tfm after allocation succeeded. Fixes: cee2688e3cd6 ("IB/rxe: Offload CRC calculation when possible") Signed-off-by: Thomas Bogendoerfer --- drivers/infiniband/sw/rxe/rxe_verbs.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.c b/drivers/infiniband/sw/rxe/rxe_verbs.c index ff77f4f66970..d03002b9d84d 100644 --- a/drivers/infiniband/sw/rxe/rxe_verbs.c +++ b/drivers/infiniband/sw/rxe/rxe_verbs.c @@ -1192,6 +1192,7 @@ int rxe_register_device(struct rxe_dev *rxe) int err; int i; struct ib_device *dev = &rxe->ib_dev; + struct crypto_shash *tfm; strlcpy(dev->name, "rxe%d", IB_DEVICE_NAME_MAX); strlcpy(dev->node_desc, "rxe", sizeof(dev->node_desc)); @@ -1289,12 +1290,13 @@ int rxe_register_device(struct rxe_dev *rxe) dev->get_hw_stats = rxe_ib_get_hw_stats; dev->alloc_hw_stats = rxe_ib_alloc_hw_stats; - rxe->tfm = crypto_alloc_shash("crc32", 0, 0); - if (IS_ERR(rxe->tfm)) { + tfm = crypto_alloc_shash("crc32", 0, 0); + if (IS_ERR(tfm)) { pr_err("failed to allocate crc algorithm err:%ld\n", - PTR_ERR(rxe->tfm)); - return PTR_ERR(rxe->tfm); + PTR_ERR(tfm)); + return PTR_ERR(tfm); } + rxe->tfm = tfm; err = ib_register_device(dev, NULL); if (err) { -- 2.12.3