Re: [PATCH 2/2] net/smc: Improve exception handling in smc_llc_cli_add_link_invite()

Tony Lu
2024-01-02T02:19:51Z

On Sun, Dec 31, 2023 at 04:00:22PM +0100, Markus Elfring wrote:
> From: Markus Elfring <elfring@users.sourceforge.net>
> Date: Sun, 31 Dec 2023 15:42:07 +0100
>
> The kfree() function was called in some cases by
> the smc_llc_cli_add_link_invite() function during error handling
> even if the passed variable contained a null pointer.
> This issue was detected by using the Coccinelle software.
>
> * Thus use another label.
>
> * Merge two if statements.
>
> * Omit an initialisation (for the variable "ini")
> which became unnecessary with this refactoring.
>
> Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>

Thank you, LGTM. Also net and Fixes tags are needed.

Reviewed-by: Tony Lu <tonylu@linux.alibaba.com>
> ---
> net/smc/smc_llc.c | 15 +++++++--------
> 1 file changed, 7 insertions(+), 8 deletions(-)
>
> diff --git a/net/smc/smc_llc.c b/net/smc/smc_llc.c
> index 018ce8133b02..2ff24a7feb26 100644
> --- a/net/smc/smc_llc.c
> +++ b/net/smc/smc_llc.c
> @@ -1163,23 +1163,21 @@ static void smc_llc_cli_add_link_invite(struct smc_link *link,
> struct smc_llc_qentry *qentry)
> {
> struct smc_link_group *lgr = smc_get_lgr(link);
> - struct smc_init_info *ini = NULL;
> + struct smc_init_info *ini;
>
> if (lgr->smc_version == SMC_V2) {
> smc_llc_send_request_add_link(link);
> - goto out;
> + goto free_qentry;
> }
>
> if (lgr->type == SMC_LGR_SYMMETRIC ||
> - lgr->type == SMC_LGR_ASYMMETRIC_PEER)
> - goto out;
> -
> - if (lgr->type == SMC_LGR_SINGLE && lgr->max_links <= 1)
> - goto out;
> + lgr->type == SMC_LGR_ASYMMETRIC_PEER ||
> + lgr->type == SMC_LGR_SINGLE && lgr->max_links <= 1)
> + goto free_qentry;
>
> ini = kzalloc(sizeof(*ini), GFP_KERNEL);
> if (!ini)
> - goto out;
> + goto free_qentry;
>
> ini->vlan_id = lgr->vlan_id;
> smc_pnet_find_alt_roce(lgr, ini, link->smcibdev);
> @@ -1190,6 +1188,7 @@ static void smc_llc_cli_add_link_invite(struct smc_link *link,
> ini->ib_gid, NULL, SMC_LLC_REQ);
> out:
> kfree(ini);
> +free_qentry:
> kfree(qentry);
> }
>
> --
> 2.43.0