Re: [PATCH 08/12] ima: Shallow copy the args_p member of ima_rule_entry.lsm elements

From: Mimi Zohar
Date: Thu Jun 25 2020 - 17:18:51 EST


On Mon, 2020-06-22 at 19:32 -0500, Tyler Hicks wrote:
> The args_p member is a simple string that is allocated by
> ima_rule_init(). Shallow copy it like other non-LSM references in
> ima_rule_entry structs.
>
> There are no longer any necessary error path cleanups to do in
> ima_lsm_copy_rule() so reference ownership from entry to nentry becomes
> easier.
>
> Signed-off-by: Tyler Hicks <tyhicks@xxxxxxxxxxxxxxxxxxx>
> ---
> security/integrity/ima/ima_policy.c | 13 ++-----------
> 1 file changed, 2 insertions(+), 11 deletions(-)
>
> diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
> index e33347148aa9..e9c7d318fdd4 100644
> --- a/security/integrity/ima/ima_policy.c
> +++ b/security/integrity/ima/ima_policy.c
> @@ -306,10 +306,8 @@ static struct ima_rule_entry *ima_lsm_copy_rule(struct ima_rule_entry *entry)
> continue;
>
> nentry->lsm[i].type = entry->lsm[i].type;
> - nentry->lsm[i].args_p = kstrdup(entry->lsm[i].args_p,
> - GFP_KERNEL);
> - if (!nentry->lsm[i].args_p)
> - goto out_err;
> + nentry->lsm[i].args_p = entry->lsm[i].args_p;
> + entry->lsm[i].args_p = NULL;

Nice.

>
> security_filter_rule_init(nentry->lsm[i].type,
> Audit_equal,
> @@ -325,13 +323,6 @@ static struct ima_rule_entry *ima_lsm_copy_rule(struct ima_rule_entry *entry)
> entry->keyrings = NULL;
> entry->template = NULL;
> return nentry;
> -
> -out_err:
> - nentry->fsname = NULL;
> - nentry->keyrings = NULL;
> - nentry->template = NULL;
> - ima_free_rule(nentry);
> - return NULL;
> }

Definitely moving ima_free_rule() to the subsequent patch makes sense.

Mimi

>
> static int ima_lsm_update_rule(struct ima_rule_entry *entry)