[PATCH 4.19 075/125] scsi: qla2xxx: Fix null pointer access during disconnect from subsystem

Greg Kroah-Hartman
2020-09-01T16:43:53Z

From: Quinn Tran <qutran@marvell.com>

[ Upstream commit 83949613fac61e8e37eadf8275bf072342302f4e ]

NVMEAsync command is being submitted to QLA while the same NVMe controller
is in the middle of reset. The reset path has deleted the association and
freed aen_op->fcp_req.private. Add a check for this private pointer before
issuing the command.

...
6 [ffffb656ca11fce0] page_fault at ffffffff8c00114e
[exception RIP: qla_nvme_post_cmd+394]
RIP: ffffffffc0d012ba RSP: ffffb656ca11fd98 RFLAGS: 00010206
RAX: ffff8fb039eda228 RBX: ffff8fb039eda200 RCX: 00000000000da161
RDX: ffffffffc0d4d0f0 RSI: ffffffffc0d26c9b RDI: ffff8fb039eda220
RBP: 0000000000000013 R8: ffff8fb47ff6aa80 R9: 0000000000000002
R10: 0000000000000000 R11: ffffb656ca11fdc8 R12: ffff8fb27d04a3b0
R13: ffff8fc46dd98a58 R14: 0000000000000000 R15: ffff8fc4540f0000
ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018
7 [ffffb656ca11fe08] nvme_fc_start_fcp_op at ffffffffc0241568 [nvme_fc]
8 [ffffb656ca11fe50] nvme_fc_submit_async_event at ffffffffc0241901 [nvme_fc]
9 [ffffb656ca11fe68] nvme_async_event_work at ffffffffc014543d [nvme_core]
10 [ffffb656ca11fe98] process_one_work at ffffffff8b6cd437
11 [ffffb656ca11fed8] worker_thread at ffffffff8b6cdcef
12 [ffffb656ca11ff10] kthread at ffffffff8b6d3402
13 [ffffb656ca11ff50] ret_from_fork at ffffffff8c000255

--
PID: 37824 TASK: ffff8fb033063d80 CPU: 20 COMMAND: "kworker/u97:451"
0 [ffffb656ce1abc28] __schedule at ffffffff8be629e3
1 [ffffb656ce1abcc8] schedule at ffffffff8be62fe8
2 [ffffb656ce1abcd0] schedule_timeout at ffffffff8be671ed
3 [ffffb656ce1abd70] wait_for_completion at ffffffff8be639cf
4 [ffffb656ce1abdd0] flush_work at ffffffff8b6ce2d5
5 [ffffb656ce1abe70] nvme_stop_ctrl at ffffffffc0144900 [nvme_core]
6 [ffffb656ce1abe80] nvme_fc_reset_ctrl_work at ffffffffc0243445 [nvme_fc]
7 [ffffb656ce1abe98] process_one_work at ffffffff8b6cd437
8 [ffffb656ce1abed8] worker_thread at ffffffff8b6cdb50
9 [ffffb656ce1abf10] kthread at ffffffff8b6d3402
10 [ffffb656ce1abf50] ret_from_fork at ffffffff8c000255

Link: https://lore.kernel.org/r/20200806111014.28434-10-njavali@marvell.com
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Quinn Tran <qutran@marvell.com>
Signed-off-by: Nilesh Javali <njavali@marvell.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/scsi/qla2xxx/qla_nvme.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/drivers/scsi/qla2xxx/qla_nvme.c b/drivers/scsi/qla2xxx/qla_nvme.c
index 5590d6e8b5762..3e2f8ce1d9a97 100644
--- a/drivers/scsi/qla2xxx/qla_nvme.c
+++ b/drivers/scsi/qla2xxx/qla_nvme.c
@@ -477,6 +477,11 @@ static int qla_nvme_post_cmd(struct nvme_fc_local_port *lport,
struct nvme_private *priv = fd->private;
struct qla_nvme_rport *qla_rport = rport->private;

+ if (!priv) {
+ /* nvme association has been torn down */
+ return rval;
+ }
+
fcport = qla_rport->fcport;

vha = fcport->vha;
--
2.25.1