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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Quinn Tran <qutran@marvell.com>,
        Mike Christie <michael.christie@oracle.com>,
        Daniel Wagner <dwagner@suse.de>,
        Himanshu Madhani <himanshu.madhani@oracle.com>,
        Bart Van Assche <bvanassche@acm.org>,
        "Martin K. Petersen" <martin.petersen@oracle.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.4 101/111] scsi: Revert "qla2xxx: Make sure that aborted commands are freed"
Date:   Mon, 29 Mar 2021 09:58:49 +0200
Message-Id: <20210329075618.581757788@linuxfoundation.org>
In-Reply-To: <20210329075615.186199980@linuxfoundation.org>
References: <20210329075615.186199980@linuxfoundation.org>
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From: Bart Van Assche <bvanassche@acm.org>

[ Upstream commit 39c0c8553bfb5a3d108aa47f1256076d507605e3 ]

Calling vha->hw->tgt.tgt_ops->free_cmd() from qlt_xmit_response() is wrong
since the command for which a response is sent must remain valid until the
SCSI target core calls .release_cmd(). It has been observed that the
following scenario triggers a kernel crash:

 - qlt_xmit_response() calls qlt_check_reserve_free_req()

 - qlt_check_reserve_free_req() returns -EAGAIN

 - qlt_xmit_response() calls vha->hw->tgt.tgt_ops->free_cmd(cmd)

 - transport_handle_queue_full() tries to retransmit the response

Fix this crash by reverting the patch that introduced it.

Link: https://lore.kernel.org/r/20210320232359.941-2-bvanassche@acm.org
Fixes: 0dcec41acb85 ("scsi: qla2xxx: Make sure that aborted commands are freed")
Cc: Quinn Tran <qutran@marvell.com>
Cc: Mike Christie <michael.christie@oracle.com>
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/scsi/qla2xxx/qla_target.c  | 13 +++++--------
 drivers/scsi/qla2xxx/tcm_qla2xxx.c |  4 ----
 2 files changed, 5 insertions(+), 12 deletions(-)

diff --git a/drivers/scsi/qla2xxx/qla_target.c b/drivers/scsi/qla2xxx/qla_target.c
index 412009e2b948..8fd0a568303b 100644
--- a/drivers/scsi/qla2xxx/qla_target.c
+++ b/drivers/scsi/qla2xxx/qla_target.c
@@ -3216,8 +3216,7 @@ int qlt_xmit_response(struct qla_tgt_cmd *cmd, int xmit_type,
 	if (!qpair->fw_started || (cmd->reset_count != qpair->chip_reset) ||
 	    (cmd->sess && cmd->sess->deleted)) {
 		cmd->state = QLA_TGT_STATE_PROCESSED;
-		res = 0;
-		goto free;
+		return 0;
 	}
 
 	ql_dbg_qp(ql_dbg_tgt, qpair, 0xe018,
@@ -3228,8 +3227,9 @@ int qlt_xmit_response(struct qla_tgt_cmd *cmd, int xmit_type,
 
 	res = qlt_pre_xmit_response(cmd, &prm, xmit_type, scsi_status,
 	    &full_req_cnt);
-	if (unlikely(res != 0))
-		goto free;
+	if (unlikely(res != 0)) {
+		return res;
+	}
 
 	spin_lock_irqsave(qpair->qp_lock_ptr, flags);
 
@@ -3249,8 +3249,7 @@ int qlt_xmit_response(struct qla_tgt_cmd *cmd, int xmit_type,
 			vha->flags.online, qla2x00_reset_active(vha),
 			cmd->reset_count, qpair->chip_reset);
 		spin_unlock_irqrestore(qpair->qp_lock_ptr, flags);
-		res = 0;
-		goto free;
+		return 0;
 	}
 
 	/* Does F/W have an IOCBs for this request */
@@ -3353,8 +3352,6 @@ int qlt_xmit_response(struct qla_tgt_cmd *cmd, int xmit_type,
 	qlt_unmap_sg(vha, cmd);
 	spin_unlock_irqrestore(qpair->qp_lock_ptr, flags);
 
-free:
-	vha->hw->tgt.tgt_ops->free_cmd(cmd);
 	return res;
 }
 EXPORT_SYMBOL(qlt_xmit_response);
diff --git a/drivers/scsi/qla2xxx/tcm_qla2xxx.c b/drivers/scsi/qla2xxx/tcm_qla2xxx.c
index 744cd93189da..df8644da2c32 100644
--- a/drivers/scsi/qla2xxx/tcm_qla2xxx.c
+++ b/drivers/scsi/qla2xxx/tcm_qla2xxx.c
@@ -623,7 +623,6 @@ static int tcm_qla2xxx_queue_data_in(struct se_cmd *se_cmd)
 {
 	struct qla_tgt_cmd *cmd = container_of(se_cmd,
 				struct qla_tgt_cmd, se_cmd);
-	struct scsi_qla_host *vha = cmd->vha;
 
 	if (cmd->aborted) {
 		/* Cmd can loop during Q-full.  tcm_qla2xxx_aborted_task
@@ -636,7 +635,6 @@ static int tcm_qla2xxx_queue_data_in(struct se_cmd *se_cmd)
 			cmd->se_cmd.transport_state,
 			cmd->se_cmd.t_state,
 			cmd->se_cmd.se_cmd_flags);
-		vha->hw->tgt.tgt_ops->free_cmd(cmd);
 		return 0;
 	}
 
@@ -664,7 +662,6 @@ static int tcm_qla2xxx_queue_status(struct se_cmd *se_cmd)
 {
 	struct qla_tgt_cmd *cmd = container_of(se_cmd,
 				struct qla_tgt_cmd, se_cmd);
-	struct scsi_qla_host *vha = cmd->vha;
 	int xmit_type = QLA_TGT_XMIT_STATUS;
 
 	if (cmd->aborted) {
@@ -678,7 +675,6 @@ static int tcm_qla2xxx_queue_status(struct se_cmd *se_cmd)
 		    cmd, kref_read(&cmd->se_cmd.cmd_kref),
 		    cmd->se_cmd.transport_state, cmd->se_cmd.t_state,
 		    cmd->se_cmd.se_cmd_flags);
-		vha->hw->tgt.tgt_ops->free_cmd(cmd);
 		return 0;
 	}
 	cmd->bufflen = se_cmd->data_length;
-- 
2.30.1