Re: [PATCH 01/12] ima: Have the LSM free its audit rule
From: Casey Schaufler <casey@schaufler-ca.com>
Date: 2020-06-23 00:56:21
Also in:
linux-integrity, lkml
On 6/22/2020 5:32 PM, Tyler Hicks wrote:
quoted hunk ↗ jump to hunk
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 <redacted> Cc: Janne Karhunen <redacted> --- 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
In context this seems perfectly reasonable. If, however, you're
working with the LSM infrastructure this set of #defines is maddening.
The existing ones have been driving my nuts for the past few years,
so I'd like to discourage adding another. Since the security_filter_rule
functions are IMA specific they shouldn't be prefixed security_. I know
that it seems to be code churn/bikesheading, but we please change these:
static inline int ima_filter_rule_init(.....)
{
return security_audit_rule_init(.....);
}
and so forth. I understand if you don't want to make the change.
I have plenty of other things driving me crazy just now, so this
doesn't seem likely to push me over the edge.
quoted hunk ↗ jump to hunk
#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; +} + 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);