Re: [PATCH -next, v2 2/2] audit: return early if the rule has a lower priority

On Wed, Oct 13, 2021 at 5:10 AM Gaosheng Cui <cuigaosheng1(a)huawei.com&gt; wrote: > It is not necessary for audit_filter_rules() functions to check > audit fileds of the rule with a lower priority, and if we did, > there might be some unintended effects, such as the ctx->ppid > may be changed unexpectedly, so return early if the rule has > a lower priority. > > Signed-off-by: Gaosheng Cui <cuigaosheng1(a)huawei.com&gt; > --- > kernel/auditsc.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) Thanks for this patch, it looks reasonable to me but have you done any testing with this patch? If so, what have you done? As a FYI, the audit-testsuite project lives here: * https://github.com/linux-audit/audit-testsuite > diff --git a/kernel/auditsc.c b/kernel/auditsc.c > index 42d4a4320526..b517947bfa48 100644 > --- a/kernel/auditsc.c > +++ b/kernel/auditsc.c > @@ -470,6 +470,9 @@ static int audit_filter_rules(struct task_struct *tsk, > u32 sid; > unsigned int sessionid; > > + if (ctx && rule->prio <= ctx->prio) > + return 0; > + > cred = rcu_dereference_check(tsk->cred, tsk == current || task_creation); > > for (i = 0; i < rule->field_count; i++) { > @@ -737,8 +740,6 @@ static int audit_filter_rules(struct task_struct *tsk, > } > > if (ctx) { > - if (rule->prio <= ctx->prio) > - return 0; > if (rule->filterkey) { > kfree(ctx->filterkey); > ctx->filterkey = kstrdup(rule->filterkey, GFP_ATOMIC); > -- > 2.30.0