[PATCH 4.9 041/207] RDMA/qedr: Fix NULL deref for query_qp on the GSI QP

[Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>]

From: Alok Prasad <palok@xxxxxxxxxxx>

commit 4f960393a0ee9a39469ceb7c8077ae8db665cc12 upstream.

This patch fixes a crash caused by querying the QP via netlink, and
corrects the state of GSI qp. GSI qp's have a NULL qed_qp.

The call trace is generated by:
 $ rdma res show

 BUG: kernel NULL pointer dereference, address: 0000000000000034
 Hardware name: Dell Inc. PowerEdge R720/0M1GCR, BIOS 1.2.6 05/10/2012
 RIP: 0010:qed_rdma_query_qp+0x33/0x1a0 [qed]
 RSP: 0018:ffffba560a08f580 EFLAGS: 00010206
 RAX: 0000000200000000 RBX: ffffba560a08f5b8 RCX: 0000000000000000
 RDX: ffffba560a08f5b8 RSI: 0000000000000000 RDI: ffff9807ee458090
 RBP: ffffba560a08f5a0 R08: 0000000000000000 R09: ffff9807890e7048
 R10: ffffba560a08f658 R11: 0000000000000000 R12: 0000000000000000
 R13: ffff9807ee458090 R14: ffff9807f0afb000 R15: ffffba560a08f7ec
 FS:  00007fbbf8bfe740(0000) GS:ffff980aafa00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000034 CR3: 00000001720ba001 CR4: 00000000000606f0
 Call Trace:
  qedr_query_qp+0x82/0x360 [qedr]
  ib_query_qp+0x34/0x40 [ib_core]
  ? ib_query_qp+0x34/0x40 [ib_core]
  fill_res_qp_entry_query.isra.26+0x47/0x1d0 [ib_core]
  ? __nla_put+0x20/0x30
  ? nla_put+0x33/0x40
  fill_res_qp_entry+0xe3/0x120 [ib_core]
  res_get_common_dumpit+0x3f8/0x5d0 [ib_core]
  ? fill_res_cm_id_entry+0x1f0/0x1f0 [ib_core]
  nldev_res_get_qp_dumpit+0x1a/0x20 [ib_core]
  netlink_dump+0x156/0x2f0
  __netlink_dump_start+0x1ab/0x260
  rdma_nl_rcv+0x1de/0x330 [ib_core]
  ? nldev_res_get_cm_id_dumpit+0x20/0x20 [ib_core]
  netlink_unicast+0x1b8/0x270
  netlink_sendmsg+0x33e/0x470
  sock_sendmsg+0x63/0x70
  __sys_sendto+0x13f/0x180
  ? setup_sgl.isra.12+0x70/0xc0
  __x64_sys_sendto+0x28/0x30
  do_syscall_64+0x3a/0xb0
  entry_SYSCALL_64_after_hwframe+0x44/0xae

Cc: stable@xxxxxxxxxxxxxxx
Fixes: cecbcddf6461 ("qedr: Add support for QP verbs")
Link: https://lore.kernel.org/r/20211027184329.18454-1-palok@xxxxxxxxxxx
Signed-off-by: Ariel Elior <aelior@xxxxxxxxxxx>
Signed-off-by: Shai Malin <smalin@xxxxxxxxxxx>
Signed-off-by: Prabhakar Kushwaha <pkushwaha@xxxxxxxxxxx>
Signed-off-by: Alok Prasad <palok@xxxxxxxxxxx>
Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/infiniband/hw/qedr/verbs.c |   15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

--- a/drivers/infiniband/hw/qedr/verbs.c
+++ b/drivers/infiniband/hw/qedr/verbs.c
@@ -2015,15 +2015,18 @@ int qedr_query_qp(struct ib_qp *ibqp,
 	int rc = 0;
 
 	memset(&params, 0, sizeof(params));
-
-	rc = dev->ops->rdma_query_qp(dev->rdma_ctx, qp->qed_qp, &params);
-	if (rc)
-		goto err;
-
 	memset(qp_attr, 0, sizeof(*qp_attr));
 	memset(qp_init_attr, 0, sizeof(*qp_init_attr));
 
-	qp_attr->qp_state = qedr_get_ibqp_state(params.state);
+	if (qp->qp_type != IB_QPT_GSI) {
+		rc = dev->ops->rdma_query_qp(dev->rdma_ctx, qp->qed_qp, &params);
+		if (rc)
+			goto err;
+		qp_attr->qp_state = qedr_get_ibqp_state(params.state);
+	} else {
+		qp_attr->qp_state = qedr_get_ibqp_state(QED_ROCE_QP_STATE_RTS);
+	}
+
 	qp_attr->cur_qp_state = qedr_get_ibqp_state(params.state);
 	qp_attr->path_mtu = iboe_get_mtu(params.mtu);
 	qp_attr->path_mig_state = IB_MIG_MIGRATED;