Re: [PATCH] tipc: stop tipc crypto on failure in tipc_node_create

[Xin Long]

On Tue, Jul 25, 2023 at 2:37 PM Fedor Pchelkin <pchelkin@xxxxxxxxx> wrote:
>
> If tipc_link_bc_create() fails inside tipc_node_create() for a newly
> allocated tipc node then we should stop its tipc crypto and free the
> resources allocated with a call to tipc_crypto_start().
>
> Call tipc_crypto_stop() in that case. Also extract the similar error exit
> paths into a goto statement.
>
> Found by Linux Verification Center (linuxtesting.org).
>
> Fixes: cb8092d70a6f ("tipc: move bc link creation back to tipc_node_create")
> Signed-off-by: Fedor Pchelkin <pchelkin@xxxxxxxxx>
> ---
>  net/tipc/node.c | 17 +++++++++++------
>  1 file changed, 11 insertions(+), 6 deletions(-)
>
> diff --git a/net/tipc/node.c b/net/tipc/node.c
> index 5e000fde8067..0d64005a803b 100644
> --- a/net/tipc/node.c
> +++ b/net/tipc/node.c
> @@ -546,9 +546,7 @@ struct tipc_node *tipc_node_create(struct net *net, u32 addr, u8 *peer_id,
>  #ifdef CONFIG_TIPC_CRYPTO
>         if (unlikely(tipc_crypto_start(&n->crypto_rx, net, n))) {
>                 pr_warn("Failed to start crypto RX(%s)!\n", n->peer_id_string);
> -               kfree(n);
> -               n = NULL;
> -               goto exit;
> +               goto free_node;
>         }
>  #endif
>         n->addr = addr;
> @@ -583,9 +581,7 @@ struct tipc_node *tipc_node_create(struct net *net, u32 addr, u8 *peer_id,
>                                  n->capabilities, &n->bc_entry.inputq1,
>                                  &n->bc_entry.namedq, snd_l, &n->bc_entry.link)) {
>                 pr_warn("Broadcast rcv link creation failed, no memory\n");
> -               kfree(n);
> -               n = NULL;
> -               goto exit;
> +               goto stop_crypto;
>         }
>         tipc_node_get(n);
Can you please try moving up tipc_node_get(n) ahead tipc_link_bc_create()
and use tipc_node_put(n) to replace kfree(n) to avoid the extra
tipc_crypto_stop() call below?

Thanks.

>         timer_setup(&n->timer, tipc_node_timeout, 0);
> @@ -610,6 +606,15 @@ struct tipc_node *tipc_node_create(struct net *net, u32 addr, u8 *peer_id,
>  exit:
>         spin_unlock_bh(&tn->node_list_lock);
>         return n;
> +stop_crypto:
> +
> +#ifdef CONFIG_TIPC_CRYPTO
> +       tipc_crypto_stop(&n->crypto_rx);
> +free_node:
> +#endif
> +       kfree(n);
> +       spin_unlock_bh(&tn->node_list_lock);
> +       return NULL;
>  }
>
>  static void tipc_node_calculate_timer(struct tipc_node *n, struct tipc_link *l)
> --
> 2.41.0
>