On 2020-06-22 19:32:25, Tyler Hicks wrote:
> Ask the LSM to free its audit rule rather than directly calling kfree().
> Both AppArmor and SELinux do additional work in their audit_rule_free()
> hooks. Fix memory leaks by allowing the LSMs to perform necessary work.
>
> Fixes: b16942455193 ("ima: use the lsm policy update notifier")
> Signed-off-by: Tyler Hicks <tyhicks@xxxxxxxxxxxxxxxxxxx>
> Cc: Janne Karhunen <janne.karhunen@xxxxxxxxx>
> ---
> security/integrity/ima/ima.h | 6 ++++++
> security/integrity/ima/ima_policy.c | 2 +-
> 2 files changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
> index df93ac258e01..de05d7f1d3ec 100644
> --- a/security/integrity/ima/ima.h
> +++ b/security/integrity/ima/ima.h
> @@ -404,6 +404,7 @@ static inline void ima_free_modsig(struct modsig *modsig)
> #ifdef CONFIG_IMA_LSM_RULES
>
> #define security_filter_rule_init security_audit_rule_init
> +#define security_filter_rule_free security_audit_rule_free
> #define security_filter_rule_match security_audit_rule_match
>
> #else
> @@ -414,6 +415,11 @@ static inline int security_filter_rule_init(u32 field, u32 op, char *rulestr,
> return -EINVAL;
> }
>
> +static inline void security_filter_rule_free(void *lsmrule)
> +{
> + return -EINVAL;
Bah, I introduced a build warning here when CONFIG_IMA_LSM_RULES is
disabled. This function should return nothing. I'll wait for additional
feedback before spinning a v2.
Tyler
> +}
> +
> static inline int security_filter_rule_match(u32 secid, u32 field, u32 op,
> void *lsmrule)
> {
> diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
> index e493063a3c34..236a731492d1 100644
> --- a/security/integrity/ima/ima_policy.c
> +++ b/security/integrity/ima/ima_policy.c
> @@ -258,7 +258,7 @@ static void ima_lsm_free_rule(struct ima_rule_entry *entry)
> int i;
>
> for (i = 0; i < MAX_LSM_RULES; i++) {
> - kfree(entry->lsm[i].rule);
> + security_filter_rule_free(entry->lsm[i].rule);
> kfree(entry->lsm[i].args_p);
> }
> kfree(entry);
> --
> 2.25.1
