[PATCH] RDMA/core: Fix null-ptr-deref in ib_core_cleanup()

[Chen Zhongjin]

KASAN reported a null-ptr-deref error:

KASAN: null-ptr-deref in range [0x0000000000000118-0x000000000000011f]
CPU: 1 PID: 379
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)
RIP: 0010:destroy_workqueue+0x2f/0x740
RSP: 0018:ffff888016137df8 EFLAGS: 00000202
...
Call Trace:
 <TASK>
 ib_core_cleanup+0xa/0xa1 [ib_core]
 __do_sys_delete_module.constprop.0+0x34f/0x5b0
 do_syscall_64+0x3a/0x90
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fa1a0d221b7
...
 </TASK>

It is because the fail of roce_gid_mgmt_init() is ignored:

ib_core_init()
  roce_gid_mgmt_init()
    gid_cache_wq = alloc_ordered_workqueue # fail
...
ib_core_cleanup()
  roce_gid_mgmt_cleanup()
    destroy_workqueue(gid_cache_wq)
    # destroy an unallocated wq

Fix this by catching the fail of roce_gid_mgmt_init() in ib_core_init().

Fixes: 03db3a2d81e6 ("IB/core: Add RoCE GID table management")
Signed-off-by: Chen Zhongjin <chenzhongjin@xxxxxxxxxx>
---
 drivers/infiniband/core/device.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/infiniband/core/device.c b/drivers/infiniband/core/device.c
index ae60c73babcc..b45431e6817b 100644
--- a/drivers/infiniband/core/device.c
+++ b/drivers/infiniband/core/device.c
@@ -2815,10 +2815,18 @@ static int __init ib_core_init(void)
 
 	nldev_init();
 	rdma_nl_register(RDMA_NL_LS, ibnl_ls_cb_table);
-	roce_gid_mgmt_init();
+	ret = roce_gid_mgmt_init();
+	if (ret) {
+		pr_warn("Couldn't init RoCE GID management\n");
+		goto err_parent;
+	}
 
 	return 0;
 
+err_parent:
+	nldev_exit();
+	rdma_nl_unregister(RDMA_NL_LS);
+	unregister_pernet_device(&rdma_dev_net_ops);
 err_compat:
 	unregister_blocking_lsm_notifier(&ibdev_lsm_nb);
 err_sa:
-- 
2.17.1