From 6e7fb2024250405d737e56985d6a86282f1175c4 Mon Sep 17 00:00:00 2001
From: Himanshu Madhani <hmadhani@redhat.com>
Date: Thu, 1 Aug 2019 15:55:51 -0400
Subject: [PATCH 091/124] [scsi] scsi: qla2xxx: Fix use-after-free issues in
 qla2xxx_qpair_sp_free_dma()

Message-id: <20190801155618.12650-92-hmadhani@redhat.com>
Patchwork-id: 267868
O-Subject: [RHEL 7.8 e-stor PATCH 091/118] scsi: qla2xxx: Fix use-after-free issues in qla2xxx_qpair_sp_free_dma()
Bugzilla: 1729270
RH-Acked-by: Jarod Wilson <jarod@redhat.com>
RH-Acked-by: Tony Camuso <tcamuso@redhat.com>

From: Bart Van Assche <bvanassche@acm.org>

Bugzilla 1729270

The current order for freeing memory is as follows:
- struct crc_context itself.
- struct crc_context member pointers.

Change the freeing order into the following:
- struct crc_context member pointers.
- struct crc_context itself.

Detected by Coverity.

Cc: Himanshu Madhani <hmadhani@marvell.com>
Cc: Giridhar Malavali <gmalavali@marvell.com>
Fixes: 50b812755e97 ("scsi: qla2xxx: Fix DMA error when the DIF sg buffer crosses 4GB boundary") # v5.1-rc1.
Fixes: d74595278f4a ("scsi: qla2xxx: Add multiple queue pair functionality.") # v4.10.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: Himanshu Madhani <hmadhani@marvell.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
(cherry picked from commit d8f945bf8096375f458683b5718722a2d5dda2f0)
Signed-off-by: Himanshu Madhani <hmadhani@redhat.com>

Conflicts:
	drivers/scsi/qla2xxx/qla_os.c

[ HM: RHEL7.8 kernel does not have wait_event_lock_irq_timeout() ]
[ commit 711a08d79f71 ("scsi: qla2xxx: Change abort wait_loop ]
[ from msleep to wait_event_timeout") was not pulled into src ]
[ resulting into deviation from upstream ]

Signed-off-by: Himanshu Madhani <hmadhani@redhat.com>
Signed-off-by: Jan Stancek <jstancek@redhat.com>
---
 drivers/scsi/qla2xxx/qla_os.c | 38 ++++++++++++++++++++------------------
 1 file changed, 20 insertions(+), 18 deletions(-)

diff --git a/drivers/scsi/qla2xxx/qla_os.c b/drivers/scsi/qla2xxx/qla_os.c
index 83d06db7e9fa..bc72d4802844 100644
--- a/drivers/scsi/qla2xxx/qla_os.c
+++ b/drivers/scsi/qla2xxx/qla_os.c
@@ -811,25 +811,8 @@ qla2xxx_qpair_sp_free_dma(void *ptr)
 		sp->flags &= ~SRB_CRC_CTX_DSD_VALID;
 	}
 
-	if (sp->flags & SRB_CRC_CTX_DMA_VALID) {
-		struct crc_context *ctx0 = ctx;
-
-		dma_pool_free(ha->dl_dma_pool, ctx, ctx0->crc_ctx_dma);
-		sp->flags &= ~SRB_CRC_CTX_DMA_VALID;
-	}
-
-	if (sp->flags & SRB_FCP_CMND_DMA_VALID) {
-		struct ct6_dsd *ctx1 = ctx;
-		dma_pool_free(ha->fcp_cmnd_dma_pool, ctx1->fcp_cmnd,
-		    ctx1->fcp_cmnd_dma);
-		list_splice(&ctx1->dsd_list, &ha->gbl_dsd_list);
-		ha->gbl_dsd_inuse -= ctx1->dsd_use_cnt;
-		ha->gbl_dsd_avail += ctx1->dsd_use_cnt;
-		mempool_free(ctx1, ha->ctx_mempool);
-		sp->flags &= ~SRB_FCP_CMND_DMA_VALID;
-	}
 	if (sp->flags & SRB_DIF_BUNDL_DMA_VALID) {
-		struct crc_context *difctx = sp->u.scmd.ctx;
+		struct crc_context *difctx = ctx;
 		struct dsd_dma *dif_dsd, *nxt_dsd;
 
 		list_for_each_entry_safe(dif_dsd, nxt_dsd,
@@ -864,6 +847,25 @@ qla2xxx_qpair_sp_free_dma(void *ptr)
 		sp->flags &= ~SRB_DIF_BUNDL_DMA_VALID;
 	}
 
+	if (sp->flags & SRB_FCP_CMND_DMA_VALID) {
+		struct ct6_dsd *ctx1 = ctx;
+
+		dma_pool_free(ha->fcp_cmnd_dma_pool, ctx1->fcp_cmnd,
+		    ctx1->fcp_cmnd_dma);
+		list_splice(&ctx1->dsd_list, &ha->gbl_dsd_list);
+		ha->gbl_dsd_inuse -= ctx1->dsd_use_cnt;
+		ha->gbl_dsd_avail += ctx1->dsd_use_cnt;
+		mempool_free(ctx1, ha->ctx_mempool);
+		sp->flags &= ~SRB_FCP_CMND_DMA_VALID;
+	}
+
+	if (sp->flags & SRB_CRC_CTX_DMA_VALID) {
+		struct crc_context *ctx0 = ctx;
+
+		dma_pool_free(ha->dl_dma_pool, ctx, ctx0->crc_ctx_dma);
+		sp->flags &= ~SRB_CRC_CTX_DMA_VALID;
+	}
+
 end:
 	CMD_SP(cmd) = NULL;
 	qla2xxx_rel_qpair_sp(sp->qpair, sp);
-- 
2.13.6