From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:59886 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730401AbeIXSsJ (ORCPT ); Mon, 24 Sep 2018 14:48:09 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dick Kennedy , James Smart , "Martin K. Petersen" , Sasha Levin Subject: [PATCH 4.18 215/235] scsi: lpfc: Fix NVME Target crash in defer rcv logic Date: Mon, 24 Sep 2018 13:53:21 +0200 Message-Id: <20180924113125.096745368@linuxfoundation.org> In-Reply-To: <20180924113103.999624566@linuxfoundation.org> References: <20180924113103.999624566@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: 4.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: James Smart [ Upstream commit 6871e8144f935a1f08e7fc6269c894861ce494aa ] Kernel occasionally crashed with the following ops on NVME Target: BUG: unable to handle kernel NULL pointer dereference at 0000000000000058 IP: [] lpfc_nvmet_defer_rcv+0x50/0x70 [lpfc] Callback routine was called for deferred rcv when it should be treated as a normal rcv. Added code in callback routine to detect this condition and log a message, then bail. Signed-off-by: Dick Kennedy Signed-off-by: James Smart Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/scsi/lpfc/lpfc_nvmet.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) --- a/drivers/scsi/lpfc/lpfc_nvmet.c +++ b/drivers/scsi/lpfc/lpfc_nvmet.c @@ -402,6 +402,7 @@ lpfc_nvmet_ctxbuf_post(struct lpfc_hba * /* Process FCP command */ if (rc == 0) { + ctxp->rqb_buffer = NULL; atomic_inc(&tgtp->rcv_fcp_cmd_out); nvmebuf->hrq->rqbp->rqb_free_buffer(phba, nvmebuf); return; @@ -1116,8 +1117,17 @@ lpfc_nvmet_defer_rcv(struct nvmet_fc_tar lpfc_nvmeio_data(phba, "NVMET DEFERRCV: xri x%x sz %d CPU %02x\n", ctxp->oxid, ctxp->size, smp_processor_id()); + if (!nvmebuf) { + lpfc_printf_log(phba, KERN_INFO, LOG_NVME_IOERR, + "6425 Defer rcv: no buffer xri x%x: " + "flg %x ste %x\n", + ctxp->oxid, ctxp->flag, ctxp->state); + return; + } + tgtp = phba->targetport->private; - atomic_inc(&tgtp->rcv_fcp_cmd_defer); + if (tgtp) + atomic_inc(&tgtp->rcv_fcp_cmd_defer); /* Free the nvmebuf since a new buffer already replaced it */ nvmebuf->hrq->rqbp->rqb_free_buffer(phba, nvmebuf);