From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Gustavo A. R. Silva" Subject: [PATCH] scsi: hisi_sas: Fix NULL pointer dereference Date: Thu, 18 Oct 2018 18:41:16 +0200 Message-ID: <20181018164116.GA24330@embeddedor.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org To: John Garry , "James E.J. Bottomley" , "Martin K. Petersen" , Xiang Chen Cc: linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" List-Id: linux-scsi@vger.kernel.org There is a NULL pointer dereference in case *slot* happens to be NULL at line 1878: struct hisi_sas_cq *cq = &hisi_hba->cq[slot->dlvry_queue]; Notice that *slot* is being NULL checked at line 1881: if (slot), which implies it may be NULL. Fix this by placing the declaration and definition of variable cq, which contains the pointer dereference slot->dlvry_queue, after *slot* has been properly NULL checked. Addresses-Coverity-ID: 1474515 ("Dereference before null check") Fixes: 584f53fe5f52 ("scsi: hisi_sas: Fix the race between IO completion and timeout for SMP/internal IO") Signed-off-by: Gustavo A. R. Silva --- drivers/scsi/hisi_sas/hisi_sas_main.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/scsi/hisi_sas/hisi_sas_main.c b/drivers/scsi/hisi_sas/hisi_sas_main.c index 2e5eaf1..e3f7c7b 100644 --- a/drivers/scsi/hisi_sas/hisi_sas_main.c +++ b/drivers/scsi/hisi_sas/hisi_sas_main.c @@ -1875,10 +1875,10 @@ hisi_sas_internal_task_abort(struct hisi_hba *hisi_hba, if ((task->task_state_flags & SAS_TASK_STATE_ABORTED)) { if (!(task->task_state_flags & SAS_TASK_STATE_DONE)) { struct hisi_sas_slot *slot = task->lldd_task; - struct hisi_sas_cq *cq = - &hisi_hba->cq[slot->dlvry_queue]; if (slot) { + struct hisi_sas_cq *cq = + &hisi_hba->cq[slot->dlvry_queue]; /* * flush tasklet to avoid free'ing task * before using task in IO completion -- 2.7.4