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>

diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index a371f857a0a908a40a960511bf047d81ade471a9..77c705c302f7a70b093d6e252cdca1e98113272d 100644 (file)
--- 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);