From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ursula Braun Subject: [PATCH net V4 5/5] net/smc: use after free fix in smc_wr_tx_put_slot() Date: Tue, 20 Nov 2018 16:46:43 +0100 Message-ID: <20181120154643.24111-6-ubraun@linux.ibm.com> References: <20181120154643.24111-1-ubraun@linux.ibm.com> Cc: netdev@vger.kernel.org, linux-s390@vger.kernel.org, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, raspl@linux.ibm.com, ubraun@linux.ibm.com To: davem@davemloft.net Return-path: Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:47704 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727488AbeKUCQq (ORCPT ); Tue, 20 Nov 2018 21:16:46 -0500 Received: from pps.filterd (m0098416.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id wAKFjodg153052 for ; Tue, 20 Nov 2018 10:46:59 -0500 Received: from e06smtp01.uk.ibm.com (e06smtp01.uk.ibm.com [195.75.94.97]) by mx0b-001b2d01.pphosted.com with ESMTP id 2nvmht2470-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Tue, 20 Nov 2018 10:46:58 -0500 Received: from localhost by e06smtp01.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 20 Nov 2018 15:46:57 -0000 In-Reply-To: <20181120154643.24111-1-ubraun@linux.ibm.com> Sender: netdev-owner@vger.kernel.org List-ID: From: Ursula Braun In smc_wr_tx_put_slot() field pend->idx is used after being cleared. That means always idx 0 is cleared in the wr_tx_mask. This results in a broken administration of available WR send payload buffers. Signed-off-by: Ursula Braun --- net/smc/smc_wr.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/net/smc/smc_wr.c b/net/smc/smc_wr.c index 3c458d279855..c2694750a6a8 100644 --- a/net/smc/smc_wr.c +++ b/net/smc/smc_wr.c @@ -215,12 +215,14 @@ int smc_wr_tx_put_slot(struct smc_link *link, pend = container_of(wr_pend_priv, struct smc_wr_tx_pend, priv); if (pend->idx < link->wr_tx_cnt) { + u32 idx = pend->idx; + /* clear the full struct smc_wr_tx_pend including .priv */ memset(&link->wr_tx_pends[pend->idx], 0, sizeof(link->wr_tx_pends[pend->idx])); memset(&link->wr_tx_bufs[pend->idx], 0, sizeof(link->wr_tx_bufs[pend->idx])); - test_and_clear_bit(pend->idx, link->wr_tx_mask); + test_and_clear_bit(idx, link->wr_tx_mask); return 1; } -- 2.16.4