sanitize audit_mq_notify()

* don't copy_from_user() twice
* don't bother with allocations
* don't duplicate parts of audit_dummy_context()
* make it return void

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/include/linux/audit.h b/include/linux/audit.h
index b7707e5..8101d2c 100644 (file)
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -453,7 +453,7 @@ extern int audit_set_macxattr(const char *name);
 extern int __audit_mq_open(int oflag, mode_t mode, struct mq_attr __user *u_attr);
 extern int __audit_mq_timedsend(mqd_t mqdes, size_t msg_len, unsigned int msg_prio, const struct timespec __user *u_abs_timeout);
 extern int __audit_mq_timedreceive(mqd_t mqdes, size_t msg_len, unsigned int __user *u_msg_prio, const struct timespec __user *u_abs_timeout);
-extern int __audit_mq_notify(mqd_t mqdes, const struct sigevent __user *u_notification);
+extern void __audit_mq_notify(mqd_t mqdes, const struct sigevent *notification);
 extern void __audit_mq_getsetattr(mqd_t mqdes, struct mq_attr *mqstat);
 extern int __audit_log_bprm_fcaps(struct linux_binprm *bprm,
                                  const struct cred *new,
@@ -494,11 +494,10 @@ static inline int audit_mq_timedreceive(mqd_t mqdes, size_t msg_len, unsigned in
                return __audit_mq_timedreceive(mqdes, msg_len, u_msg_prio, u_abs_timeout);
        return 0;
 }
-static inline int audit_mq_notify(mqd_t mqdes, const struct sigevent __user *u_notification)
+static inline void audit_mq_notify(mqd_t mqdes, const struct sigevent *notification)
 {
        if (unlikely(!audit_dummy_context()))
-               return __audit_mq_notify(mqdes, u_notification);
-       return 0;
+               __audit_mq_notify(mqdes, notification);
 }
 static inline void audit_mq_getsetattr(mqd_t mqdes, struct mq_attr *mqstat)
 {
@@ -553,7 +552,7 @@ extern int audit_signals;
 #define audit_mq_open(o,m,a) ({ 0; })
 #define audit_mq_timedsend(d,l,p,t) ({ 0; })
 #define audit_mq_timedreceive(d,l,p,t) ({ 0; })
-#define audit_mq_notify(d,n) ({ 0; })
+#define audit_mq_notify(d,n) ((void)0)
 #define audit_mq_getsetattr(d,s) ((void)0)
 #define audit_log_bprm_fcaps(b, ncr, ocr) ({ 0; })
 #define audit_log_capset(pid, ncr, ocr) ({ 0; })

diff --git a/ipc/mqueue.c b/ipc/mqueue.c
index 7563611..e7b2f68 100644 (file)
--- a/ipc/mqueue.c
+++ b/ipc/mqueue.c
@@ -1003,17 +1003,17 @@ asmlinkage long sys_mq_notify(mqd_t mqdes,
        struct mqueue_inode_info *info;
        struct sk_buff *nc;
 
-       ret = audit_mq_notify(mqdes, u_notification);
-       if (ret != 0)
-               return ret;
-
-       nc = NULL;
-       sock = NULL;
-       if (u_notification != NULL) {
+       if (u_notification) {
                if (copy_from_user(&notification, u_notification,
                                        sizeof(struct sigevent)))
                        return -EFAULT;
+       }
+
+       audit_mq_notify(mqdes, u_notification ? &notification : NULL);
 
+       nc = NULL;
+       sock = NULL;
+       if (u_notification != NULL) {
                if (unlikely(notification.sigev_notify != SIGEV_NONE &&
                             notification.sigev_notify != SIGEV_SIGNAL &&
                             notification.sigev_notify != SIGEV_THREAD))

diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index c50178c..3ece960 100644 (file)
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -139,12 +139,6 @@ struct audit_aux_data_mq_sendrecv {
        struct timespec         abs_timeout;
 };
 
-struct audit_aux_data_mq_notify {
-       struct audit_aux_data   d;
-       mqd_t                   mqdes;
-       struct sigevent         notification;
-};
-
 struct audit_aux_data_execve {
        struct audit_aux_data   d;
        int argc;
@@ -246,6 +240,10 @@ struct audit_context {
                        mqd_t                   mqdes;
                        struct mq_attr          mqstat;
                } mq_getsetattr;
+               struct {
+                       mqd_t                   mqdes;
+                       int                     sigev_signo;
+               } mq_notify;
        };
 
 #if AUDIT_DEBUG
@@ -1267,6 +1265,11 @@ static void show_special(struct audit_context *context, int *call_panic)
                                return;
                }
                break; }
+       case AUDIT_MQ_NOTIFY: {
+               audit_log_format(ab, "mqdes=%d sigev_signo=%d",
+                               context->mq_notify.mqdes,
+                               context->mq_notify.sigev_signo);
+               break; }
        case AUDIT_MQ_GETSETATTR: {
                struct mq_attr *attr = &context->mq_getsetattr.mqstat;
                audit_log_format(ab,
@@ -1376,14 +1379,6 @@ static void audit_log_exit(struct audit_context *context, struct task_struct *ts
                                axi->abs_timeout.tv_sec, axi->abs_timeout.tv_nsec);
                        break; }
 
-               case AUDIT_MQ_NOTIFY: {
-                       struct audit_aux_data_mq_notify *axi = (void *)aux;
-                       audit_log_format(ab,
-                               "mqdes=%d sigev_signo=%d",
-                               axi->mqdes,
-                               axi->notification.sigev_signo);
-                       break; }
-
                case AUDIT_EXECVE: {
                        struct audit_aux_data_execve *axi = (void *)aux;
                        audit_log_execve_info(context, &ab, axi);
@@ -2274,38 +2269,19 @@ int __audit_mq_timedreceive(mqd_t mqdes, size_t msg_len,
  * @mqdes: MQ descriptor
  * @u_notification: Notification event
  *
- * Returns 0 for success or NULL context or < 0 on error.
  */
 
-int __audit_mq_notify(mqd_t mqdes, const struct sigevent __user *u_notification)
+void __audit_mq_notify(mqd_t mqdes, const struct sigevent *notification)
 {
-       struct audit_aux_data_mq_notify *ax;
        struct audit_context *context = current->audit_context;
 
-       if (!audit_enabled)
-               return 0;
-
-       if (likely(!context))
-               return 0;
-
-       ax = kmalloc(sizeof(*ax), GFP_ATOMIC);
-       if (!ax)
-               return -ENOMEM;
-
-       if (u_notification != NULL) {
-               if (copy_from_user(&ax->notification, u_notification, sizeof(ax->notification))) {
-                       kfree(ax);
-                       return -EFAULT;
-               }
-       } else
-               memset(&ax->notification, 0, sizeof(ax->notification));
-
-       ax->mqdes = mqdes;
+       if (notification)
+               context->mq_notify.sigev_signo = notification->sigev_signo;
+       else
+               context->mq_notify.sigev_signo = 0;
 
-       ax->d.type = AUDIT_MQ_NOTIFY;
-       ax->d.next = context->aux;
-       context->aux = (void *)ax;
-       return 0;
+       context->mq_notify.mqdes = mqdes;
+       context->type = AUDIT_MQ_NOTIFY;
 }
 
 /**