RDMA/siw: Fix failure handling during device creation

BugLink: https://bugs.launchpad.net/bugs/1867178
commit 12e5eef0f4d8087ea7b559f6630be08ffea2d851 upstream.

A failing call to ib_device_set_netdev() during device creation caused
system crash due to xa_destroy of uninitialized xarray hit by device
deallocation. Fixed by moving xarray initialization before potential
device deallocation.

Fixes: bdcf26bf9b3a ("rdma/siw: network and RDMA core interface")
Link: https://lore.kernel.org/r/20200302155814.9896-1-bmt@zurich.ibm.com
Reported-by: syzbot+2e80962bedd9559fe0b3@syzkaller.appspotmail.com
Signed-off-by: Bernard Metzler <bmt@zurich.ibm.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com>

diff --git a/drivers/infiniband/sw/siw/siw_main.c b/drivers/infiniband/sw/siw/siw_main.c
index fb01407a310fadbb725bf6a6303759d21072c7df..130b1e31b97804be92e4053a441596dcaa5d6469 100644 (file)
--- a/drivers/infiniband/sw/siw/siw_main.c
+++ b/drivers/infiniband/sw/siw/siw_main.c
@@ -379,6 +379,9 @@ static struct siw_device *siw_device_create(struct net_device *netdev)
        base_dev->dev.dma_ops = &dma_virt_ops;
        base_dev->num_comp_vectors = num_possible_cpus();
 
+       xa_init_flags(&sdev->qp_xa, XA_FLAGS_ALLOC1);
+       xa_init_flags(&sdev->mem_xa, XA_FLAGS_ALLOC1);
+
        ib_set_device_ops(base_dev, &siw_device_ops);
        rv = ib_device_set_netdev(base_dev, netdev, 1);
        if (rv)
@@ -406,9 +409,6 @@ static struct siw_device *siw_device_create(struct net_device *netdev)
        sdev->attrs.max_srq_wr = SIW_MAX_SRQ_WR;
        sdev->attrs.max_srq_sge = SIW_MAX_SGE;
 
-       xa_init_flags(&sdev->qp_xa, XA_FLAGS_ALLOC1);
-       xa_init_flags(&sdev->mem_xa, XA_FLAGS_ALLOC1);
-
        INIT_LIST_HEAD(&sdev->cep_list);
        INIT_LIST_HEAD(&sdev->qp_list);