audit: improve GID/EGID comparation logic

It is useful to extend GID/EGID comparation logic to be able to
match not only the exact EID/EGID values but the group/egroup also.

Signed-off-by: Matvejchikov Ilya <matvejchikov@gmail.com>
Signed-off-by: Eric Paris <eparis@redhat.com>

1 files changed, 14 insertions, 0 deletions

diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index a371f857a0a9..77c705c302f7 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -633,9 +633,23 @@ static int audit_filter_rules(struct task_struct *tsk,
                         break;
                 case AUDIT_GID:
                         result = audit_gid_comparator(cred->gid, f->op, f->gid);
+                        if (f->op == Audit_equal) {
+                                if (!result)
+                                        result = in_group_p(f->gid);
+                        } else if (f->op == Audit_not_equal) {
+                                if (result)
+                                        result = !in_group_p(f->gid);
+                        }
                         break;
                 case AUDIT_EGID:
                         result = audit_gid_comparator(cred->egid, f->op, f->gid);
+                        if (f->op == Audit_equal) {
+                                if (!result)
+                                        result = in_egroup_p(f->gid);
+                        } else if (f->op == Audit_not_equal) {
+                                if (result)
+                                        result = !in_egroup_p(f->gid);
+                        }
                         break;
                 case AUDIT_SGID:
                         result = audit_gid_comparator(cred->sgid, f->op, f->gid);