Re: [PATCH v2 3/3] netlabel: Less function calls in netlbl_mgmt_add_common() after error detection

Paul Moore
2015-02-01T14:39:47Z

On Sun, Feb 1, 2015 at 5:15 AM, SF Markus Elfring
<elfring@users.sourceforge.net> wrote:
> From: Markus Elfring <elfring@users.sourceforge.net>
> Date: Sun, 1 Feb 2015 11:11:29 +0100
>
> The functions "cipso_v4_doi_putdef" and "kfree" could be called in some cases
> by the netlbl_mgmt_add_common() function during error handling even if the
> passed variables contained still a null pointer.
>
> * This implementation detail could be improved by adjustments for jump labels.
>
> * Let us return immediately after the first failed function call according to
> the current Linux coding style convention.
>
> * Let us delete also an unnecessary check for the variable "entry" there.
>
> Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
> ---
> net/netlabel/netlabel_mgmt.c | 49 ++++++++++++++++++++++----------------------
> 1 file changed, 24 insertions(+), 25 deletions(-)

Thanks for fixing the label names.

Acked-by: Paul Moore <paul@paul-moore.com>

> diff --git a/net/netlabel/netlabel_mgmt.c b/net/netlabel/netlabel_mgmt.c
> index f5807f5..7044074 100644
> --- a/net/netlabel/netlabel_mgmt.c
> +++ b/net/netlabel/netlabel_mgmt.c
> @@ -93,23 +93,20 @@ static int netlbl_mgmt_add_common(struct genl_info *info,
> struct netlbl_audit *audit_info)
> {
> int ret_val = -EINVAL;
> - struct netlbl_dom_map *entry = NULL;
> struct netlbl_domaddr_map *addrmap = NULL;
> struct cipso_v4_doi *cipsov4 = NULL;
> u32 tmp_val;
> + struct netlbl_dom_map *entry = kzalloc(sizeof(*entry), GFP_KERNEL);
>
> - entry = kzalloc(sizeof(*entry), GFP_KERNEL);
> - if (entry = NULL) {
> - ret_val = -ENOMEM;
> - goto add_failure;
> - }
> + if (!entry)
> + return -ENOMEM;
> entry->def.type = nla_get_u32(info->attrs[NLBL_MGMT_A_PROTOCOL]);
> if (info->attrs[NLBL_MGMT_A_DOMAIN]) {
> size_t tmp_size = nla_len(info->attrs[NLBL_MGMT_A_DOMAIN]);
> entry->domain = kmalloc(tmp_size, GFP_KERNEL);
> if (entry->domain = NULL) {
> ret_val = -ENOMEM;
> - goto add_failure;
> + goto add_free_entry;
> }
> nla_strlcpy(entry->domain,
> info->attrs[NLBL_MGMT_A_DOMAIN], tmp_size);
> @@ -125,16 +122,16 @@ static int netlbl_mgmt_add_common(struct genl_info *info,
> break;
> case NETLBL_NLTYPE_CIPSOV4:
> if (!info->attrs[NLBL_MGMT_A_CV4DOI])
> - goto add_failure;
> + goto add_free_domain;
>
> tmp_val = nla_get_u32(info->attrs[NLBL_MGMT_A_CV4DOI]);
> cipsov4 = cipso_v4_doi_getdef(tmp_val);
> if (cipsov4 = NULL)
> - goto add_failure;
> + goto add_free_domain;
> entry->def.cipso = cipsov4;
> break;
> default:
> - goto add_failure;
> + goto add_free_domain;
> }
>
> if (info->attrs[NLBL_MGMT_A_IPV4ADDR]) {
> @@ -145,7 +142,7 @@ static int netlbl_mgmt_add_common(struct genl_info *info,
> addrmap = kzalloc(sizeof(*addrmap), GFP_KERNEL);
> if (addrmap = NULL) {
> ret_val = -ENOMEM;
> - goto add_failure;
> + goto add_doi_put_def;
> }
> INIT_LIST_HEAD(&addrmap->list4);
> INIT_LIST_HEAD(&addrmap->list6);
> @@ -153,12 +150,12 @@ static int netlbl_mgmt_add_common(struct genl_info *info,
> if (nla_len(info->attrs[NLBL_MGMT_A_IPV4ADDR]) !> sizeof(struct in_addr)) {
> ret_val = -EINVAL;
> - goto add_failure;
> + goto add_free_addrmap;
> }
> if (nla_len(info->attrs[NLBL_MGMT_A_IPV4MASK]) !> sizeof(struct in_addr)) {
> ret_val = -EINVAL;
> - goto add_failure;
> + goto add_free_addrmap;
> }
> addr = nla_data(info->attrs[NLBL_MGMT_A_IPV4ADDR]);
> mask = nla_data(info->attrs[NLBL_MGMT_A_IPV4MASK]);
> @@ -166,7 +163,7 @@ static int netlbl_mgmt_add_common(struct genl_info *info,
> map = kzalloc(sizeof(*map), GFP_KERNEL);
> if (map = NULL) {
> ret_val = -ENOMEM;
> - goto add_failure;
> + goto add_free_addrmap;
> }
> map->list.addr = addr->s_addr & mask->s_addr;
> map->list.mask = mask->s_addr;
> @@ -178,7 +175,7 @@ static int netlbl_mgmt_add_common(struct genl_info *info,
> ret_val = netlbl_af4list_add(&map->list, &addrmap->list4);
> if (ret_val != 0) {
> kfree(map);
> - goto add_failure;
> + goto add_free_addrmap;
> }
>
> entry->def.type = NETLBL_NLTYPE_ADDRSELECT;
> @@ -192,7 +189,7 @@ static int netlbl_mgmt_add_common(struct genl_info *info,
> addrmap = kzalloc(sizeof(*addrmap), GFP_KERNEL);
> if (addrmap = NULL) {
> ret_val = -ENOMEM;
> - goto add_failure;
> + goto add_doi_put_def;
> }
> INIT_LIST_HEAD(&addrmap->list4);
> INIT_LIST_HEAD(&addrmap->list6);
> @@ -200,12 +197,12 @@ static int netlbl_mgmt_add_common(struct genl_info *info,
> if (nla_len(info->attrs[NLBL_MGMT_A_IPV6ADDR]) !> sizeof(struct in6_addr)) {
> ret_val = -EINVAL;
> - goto add_failure;
> + goto add_free_addrmap;
> }
> if (nla_len(info->attrs[NLBL_MGMT_A_IPV6MASK]) !> sizeof(struct in6_addr)) {
> ret_val = -EINVAL;
> - goto add_failure;
> + goto add_free_addrmap;
> }
> addr = nla_data(info->attrs[NLBL_MGMT_A_IPV6ADDR]);
> mask = nla_data(info->attrs[NLBL_MGMT_A_IPV6MASK]);
> @@ -213,7 +210,7 @@ static int netlbl_mgmt_add_common(struct genl_info *info,
> map = kzalloc(sizeof(*map), GFP_KERNEL);
> if (map = NULL) {
> ret_val = -ENOMEM;
> - goto add_failure;
> + goto add_free_addrmap;
> }
> map->list.addr = *addr;
> map->list.addr.s6_addr32[0] &= mask->s6_addr32[0];
> @@ -227,7 +224,7 @@ static int netlbl_mgmt_add_common(struct genl_info *info,
> ret_val = netlbl_af6list_add(&map->list, &addrmap->list6);
> if (ret_val != 0) {
> kfree(map);
> - goto add_failure;
> + goto add_free_addrmap;
> }
>
> entry->def.type = NETLBL_NLTYPE_ADDRSELECT;
> @@ -237,15 +234,17 @@ static int netlbl_mgmt_add_common(struct genl_info *info,
>
> ret_val = netlbl_domhsh_add(entry, audit_info);
> if (ret_val != 0)
> - goto add_failure;
> + goto add_free_addrmap;
>
> return 0;
>
> -add_failure:
> - cipso_v4_doi_putdef(cipsov4);
> - if (entry)
> - kfree(entry->domain);
> +add_free_addrmap:
> kfree(addrmap);
> +add_doi_put_def:
> + cipso_v4_doi_putdef(cipsov4);
> +add_free_domain:
> + kfree(entry->domain);
> +add_free_entry:
> kfree(entry);
> return ret_val;
> }
> --
> 2.2.2
>

--
paul moore