From: Quinn Tran <qutran@xxxxxxxxxxx> System crash due to command failed to flush back to scsi layer. BUG: unable to handle kernel NULL pointer dereference at 0000000000000000 PGD 0 P4D 0 Oops: 0000 [#1] SMP NOPTI CPU: 27 PID: 793455 Comm: kworker/u130:6 Kdump: loaded Tainted: G OE --------- - - 4.18.0-372.9.1.el8.x86_64 #1 Hardware name: HPE ProLiant DL360 Gen10/ProLiant DL360 Gen10, BIOS U32 09/03/2021 Workqueue: nvme-wq nvme_fc_connect_ctrl_work [nvme_fc] RIP: 0010:__wake_up_common+0x4c/0x190 Code: 24 10 4d 85 c9 74 0a 41 f6 01 04 0f 85 9d 00 00 00 48 8b 43 08 48 83 c3 08 4c 8d 48 e8 49 8d 41 18 48 39 c3 0f 84 f0 00 00 00 <49> 8b 41 18 89 54 24 08 31 ed 4c 8d 70 e8 45 8b 29 41 f6 c5 04 75 RSP: 0018:ffff95f3e0cb7cd0 EFLAGS: 00010086 RAX: 0000000000000000 RBX: ffff8b08d3b26328 RCX: 0000000000000000 RDX: 0000000000000001 RSI: 0000000000000003 RDI: ffff8b08d3b26320 RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffffffffffe8 R10: 0000000000000000 R11: ffff95f3e0cb7a60 R12: ffff95f3e0cb7d20 R13: 0000000000000003 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8b2fdf6c0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000002f1e410002 CR4: 00000000007706e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: __wake_up_common_lock+0x7c/0xc0 qla_nvme_ls_req+0x355/0x4c0 [qla2xxx] qla2xxx [0000:12:00.1]-f084:3: qlt_free_session_done: se_sess 0000000000000000 / sess ffff8ae1407ca000 from port 21:32:00:02:ac:07:ee:b8 loop_id 0x02 s_id 01:02:00 logout 1 keep 0 els_logo 0 ? __nvme_fc_send_ls_req+0x260/0x380 [nvme_fc] qla2xxx [0000:12:00.1]-207d:3: FCPort 21:32:00:02:ac:07:ee:b8 state transitioned from ONLINE to LOST - portid=010200. ? nvme_fc_send_ls_req.constprop.42+0x1a/0x45 [nvme_fc] qla2xxx [0000:12:00.1]-2109:3: qla2x00_schedule_rport_del 21320002ac07eeb8. rport ffff8ae598122000 roles 1 ? nvme_fc_connect_ctrl_work.cold.63+0x1e3/0xa7d [nvme_fc] qla2xxx [0000:12:00.1]-f084:3: qlt_free_session_done: se_sess 0000000000000000 / sess ffff8ae14801e000 from port 21:32:01:02:ad:f7:ee:b8 loop_id 0x04 s_id 01:02:01 logout 1 keep 0 els_logo 0 ? __switch_to+0x10c/0x450 ? process_one_work+0x1a7/0x360 qla2xxx [0000:12:00.1]-207d:3: FCPort 21:32:01:02:ad:f7:ee:b8 state transitioned from ONLINE to LOST - portid=010201. ? worker_thread+0x1ce/0x390 ? create_worker+0x1a0/0x1a0 qla2xxx [0000:12:00.1]-2109:3: qla2x00_schedule_rport_del 21320102adf7eeb8. rport ffff8ae3b2312800 roles 70 ? kthread+0x10a/0x120 qla2xxx [0000:12:00.1]-2112:3: qla_nvme_unregister_remote_port: unregister remoteport on ffff8ae14801e000 21320102adf7eeb8 ? set_kthread_struct+0x40/0x40 qla2xxx [0000:12:00.1]-2110:3: remoteport_delete of ffff8ae14801e000 21320102adf7eeb8 completed. ? ret_from_fork+0x1f/0x40 qla2xxx [0000:12:00.1]-f086:3: qlt_free_session_done: waiting for sess ffff8ae14801e000 logout The system was under memory stress where driver was not able to allocate a srb to carry out error recovery of cable pull. The failure to flush cause upper layer to start modifying scsi_cmnd. When the system free up some memory, the subsequent cable pull trigger another command flush. At this point the driver access a null pointer when attempting to dma unmap the SGL. Add a check to make sure commands are flush back on session tear down to prevent the null pointer access. Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Quinn Tran <qutran@xxxxxxxxxxx> Signed-off-by: Nilesh Javali <njavali@xxxxxxxxxxx> Reviewed-by: Himanshu Madhani <himanshu.madhani@xxxxxxxxxx> --- drivers/scsi/qla2xxx/qla_target.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/scsi/qla2xxx/qla_target.c b/drivers/scsi/qla2xxx/qla_target.c index 2ef2dbac0db2..d7551b1443e4 100644 --- a/drivers/scsi/qla2xxx/qla_target.c +++ b/drivers/scsi/qla2xxx/qla_target.c @@ -1062,6 +1062,16 @@ void qlt_free_session_done(struct work_struct *work) "%s: sess %p logout completed\n", __func__, sess); } + /* check for any straggling io left behind */ + if (!(sess->flags & FCF_FCP2_DEVICE) && + qla2x00_eh_wait_for_pending_commands(sess->vha, sess->d_id.b24, 0, WAIT_TARGET)) { + ql_log(ql_log_warn, vha, 0x3027, + "IO not return. Resetting.\n"); + set_bit(ISP_ABORT_NEEDED, &vha->dpc_flags); + qla2xxx_wake_dpc(vha); + qla2x00_wait_for_chip_reset(vha); + } + if (sess->logo_ack_needed) { sess->logo_ack_needed = 0; qla24xx_async_notify_ack(vha, sess, -- 2.23.1