[PATCH 5.10 202/221] scsi: Revert "qla2xxx: Make sure that aborted commands are freed"

From: Greg Kroah-Hartman
Date: Mon Mar 29 2021 - 04:48:05 EST


From: Bart Van Assche <bvanassche@xxxxxxx>

[ 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@xxxxxxx
Fixes: 0dcec41acb85 ("scsi: qla2xxx: Make sure that aborted commands are freed")
Cc: Quinn Tran <qutran@xxxxxxxxxxx>
Cc: Mike Christie <michael.christie@xxxxxxxxxx>
Reviewed-by: Daniel Wagner <dwagner@xxxxxxx>
Reviewed-by: Himanshu Madhani <himanshu.madhani@xxxxxxxxxx>
Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
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 a27a625839e6..dcae8f071c35 100644
--- a/drivers/scsi/qla2xxx/qla_target.c
+++ b/drivers/scsi/qla2xxx/qla_target.c
@@ -3222,8 +3222,7 @@ 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,
@@ -3234,8 +3233,9 @@ 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);

@@ -3255,8 +3255,7 @@ 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 */
@@ -3359,8 +3358,6 @@ 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 61017acd3458..7405fab324c8 100644
--- a/drivers/scsi/qla2xxx/tcm_qla2xxx.c
+++ b/drivers/scsi/qla2xxx/tcm_qla2xxx.c
@@ -646,7 +646,6 @@ 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
@@ -659,7 +658,6 @@ 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;
}

@@ -687,7 +685,6 @@ 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) {
@@ -701,7 +698,6 @@ 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