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

[Leon Romanovsky <leon@kernel.org>]

On Tue, Oct 25, 2022 at 10:41:46AM +0800, Chen Zhongjin wrote:
> 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@huawei.com>
> ---
>  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);

I fixed release flow and applied to -rc.

diff --git a/drivers/infiniband/core/device.c b/drivers/infiniband/core/device.c
index b45431e6817b..b69e2c4e4d2a 100644
--- a/drivers/infiniband/core/device.c
+++ b/drivers/infiniband/core/device.c
@@ -2824,8 +2824,8 @@ static int __init ib_core_init(void)
        return 0;

 err_parent:
-       nldev_exit();
        rdma_nl_unregister(RDMA_NL_LS);
+       nldev_exit();
        unregister_pernet_device(&rdma_dev_net_ops);
 err_compat:
        unregister_blocking_lsm_notifier(&ibdev_lsm_nb);

Thanks


>  err_compat:
>  	unregister_blocking_lsm_notifier(&ibdev_lsm_nb);
>  err_sa:
> -- 
> 2.17.1
>