RDMA/siw: Fix handling of zero-sized Read and Receive Queues.

During connection setup, the application may choose to zero-size inbound
and outbound READ queues, as well as the Receive queue.  This patch fixes
handling of zero-sized queues, but not prevents it.

Kamal Heib says in an initial error report:

 When running the blktests over siw the following shift-out-of-bounds is
 reported, this is happening because the passed IRD or ORD from the ulp
 could be zero which will lead to unexpected behavior when calling
 roundup_pow_of_two(), fix that by blocking zero values of ORD or IRD.

   UBSAN: shift-out-of-bounds in ./include/linux/log2.h:57:13
   shift exponent 64 is too large for 64-bit type 'long unsigned int'
   CPU: 20 PID: 3957 Comm: kworker/u64:13 Tainted: G S     5.10.0-rc6 #2
   Hardware name: Dell Inc. PowerEdge R630/02C2CP, BIOS 2.1.5 04/11/2016
   Workqueue: iw_cm_wq cm_work_handler [iw_cm]
   Call Trace:
    dump_stack+0x99/0xcb
    ubsan_epilogue+0x5/0x40
    __ubsan_handle_shift_out_of_bounds.cold.11+0xb4/0xf3
    ? down_write+0x183/0x3d0
    siw_qp_modify.cold.8+0x2d/0x32 [siw]
    ? __local_bh_enable_ip+0xa5/0xf0
    siw_accept+0x906/0x1b60 [siw]
    ? xa_load+0x147/0x1f0
    ? siw_connect+0x17a0/0x17a0 [siw]
    ? lock_downgrade+0x700/0x700
    ? siw_get_base_qp+0x1c2/0x340 [siw]
    ? _raw_spin_unlock_irqrestore+0x39/0x40
    iw_cm_accept+0x1f4/0x430 [iw_cm]
    rdma_accept+0x3fa/0xb10 [rdma_cm]
    ? check_flush_dependency+0x410/0x410
    ? cma_rep_recv+0x570/0x570 [rdma_cm]
    nvmet_rdma_queue_connect+0x1a62/0x2680 [nvmet_rdma]
    ? nvmet_rdma_alloc_cmds+0xce0/0xce0 [nvmet_rdma]
    ? lock_release+0x56e/0xcc0
    ? lock_downgrade+0x700/0x700
    ? lock_downgrade+0x700/0x700
    ? __xa_alloc_cyclic+0xef/0x350
    ? __xa_alloc+0x2d0/0x2d0
    ? rdma_restrack_add+0xbe/0x2c0 [ib_core]
    ? __ww_mutex_die+0x190/0x190
    cma_cm_event_handler+0xf2/0x500 [rdma_cm]
    iw_conn_req_handler+0x910/0xcb0 [rdma_cm]
    ? _raw_spin_unlock_irqrestore+0x39/0x40
    ? trace_hardirqs_on+0x1c/0x150
    ? cma_ib_handler+0x8a0/0x8a0 [rdma_cm]
    ? __kasan_kmalloc.constprop.7+0xc1/0xd0
    cm_work_handler+0x121c/0x17a0 [iw_cm]
    ? iw_cm_reject+0x190/0x190 [iw_cm]
    ? trace_hardirqs_on+0x1c/0x150
    process_one_work+0x8fb/0x16c0
    ? pwq_dec_nr_in_flight+0x320/0x320
    worker_thread+0x87/0xb40
    ? __kthread_parkme+0xd1/0x1a0
    ? process_one_work+0x16c0/0x16c0
    kthread+0x35f/0x430
    ? kthread_mod_delayed_work+0x180/0x180
    ret_from_fork+0x22/0x30

Fixes: a531975279f3 ("rdma/siw: main include file")
Fixes: f29dd55b0236 ("rdma/siw: queue pair methods")
Fixes: 8b6a361b8c48 ("rdma/siw: receive path")
Fixes: b9be6f18cf9e ("rdma/siw: transmit path")
Fixes: 303ae1cdfdf7 ("rdma/siw: application interface")
Link: https://lore.kernel.org/r/20210108125845.1803-1-bmt@zurich.ibm.com
Reported-by: Kamal Heib <kamalheib1@gmail.com>
Reported-by: Yi Zhang <yi.zhang@redhat.com>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Bernard Metzler <bmt@zurich.ibm.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

1 files changed, 18 insertions, 8 deletions

diff --git a/drivers/infiniband/sw/siw/siw_qp_rx.c b/drivers/infiniband/sw/siw/siw_qp_rx.c
index 4bd1f1f84057..60116f20653c 100644
--- a/drivers/infiniband/sw/siw/siw_qp_rx.c
+++ b/drivers/infiniband/sw/siw/siw_qp_rx.c
@@ -680,6 +680,10 @@ static int siw_init_rresp(struct siw_qp *qp, struct siw_rx_stream *srx)
 	}
 	spin_lock_irqsave(&qp->sq_lock, flags);
 
+	if (unlikely(!qp->attrs.irq_size)) {
+		run_sq = 0;
+		goto error_irq;
+	}
 	if (tx_work->wr_status == SIW_WR_IDLE) {
 		/*
 		 * immediately schedule READ response w/o
@@ -712,8 +716,9 @@ static int siw_init_rresp(struct siw_qp *qp, struct siw_rx_stream *srx)
 		/* RRESP now valid as current TX wqe or placed into IRQ */
 		smp_store_mb(resp->flags, SIW_WQE_VALID);
 	} else {
-		pr_warn("siw: [QP %u]: irq %d exceeded %d\n", qp_id(qp),
-			qp->irq_put % qp->attrs.irq_size, qp->attrs.irq_size);
+error_irq:
+		pr_warn("siw: [QP %u]: IRQ exceeded or null, size %d\n",
+			qp_id(qp), qp->attrs.irq_size);
 
 		siw_init_terminate(qp, TERM_ERROR_LAYER_RDMAP,
 				   RDMAP_ETYPE_REMOTE_OPERATION,
@@ -740,6 +745,9 @@ static int siw_orqe_start_rx(struct siw_qp *qp)
 	struct siw_sqe *orqe;
 	struct siw_wqe *wqe = NULL;
 
+	if (unlikely(!qp->attrs.orq_size))
+		return -EPROTO;
+
 	/* make sure ORQ indices are current */
 	smp_mb();
 
@@ -796,8 +804,8 @@ int siw_proc_rresp(struct siw_qp *qp)
 		 */
 		rv = siw_orqe_start_rx(qp);
 		if (rv) {
-			pr_warn("siw: [QP %u]: ORQ empty at idx %d\n",
-				qp_id(qp), qp->orq_get % qp->attrs.orq_size);
+			pr_warn("siw: [QP %u]: ORQ empty, size %d\n",
+				qp_id(qp), qp->attrs.orq_size);
 			goto error_term;
 		}
 		rv = siw_rresp_check_ntoh(srx, frx);
@@ -1290,11 +1298,13 @@ static int siw_rdmap_complete(struct siw_qp *qp, int error)
 					      wc_status);
 		siw_wqe_put_mem(wqe, SIW_OP_READ);
 
-		if (!error)
+		if (!error) {
 			rv = siw_check_tx_fence(qp);
-		else
-			/* Disable current ORQ eleement */
-			WRITE_ONCE(orq_get_current(qp)->flags, 0);
+		} else {
+			/* Disable current ORQ element */
+			if (qp->attrs.orq_size)
+				WRITE_ONCE(orq_get_current(qp)->flags, 0);
+		}
 		break;
 
 	case RDMAP_RDMA_READ_REQ: