sanitize AUDIT_MQ_SENDRECV

* logging the original value of *msg_prio in mq_timedreceive(2)
  is insane - the argument is write-only (i.e. syscall always
  ignores the original value and only overwrites it).
* merge __audit_mq_timed{send,receive}
* don't do copy_from_user() twice
* don't mess with allocations in auditsc part
* ... and don't bother checking !audit_enabled and !context in there -
  we'd already checked for audit_dummy_context().

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

diff --git a/include/linux/audit.h b/include/linux/audit.h
index 8101d2c..67f0cdd 100644 (file)
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -451,8 +451,7 @@ extern int audit_sockaddr(int len, void *addr);
 extern int __audit_fd_pair(int fd1, int fd2);
 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 void __audit_mq_sendrecv(mqd_t mqdes, size_t msg_len, unsigned int msg_prio, const struct timespec *abs_timeout);
 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,
@@ -482,17 +481,10 @@ static inline int audit_mq_open(int oflag, mode_t mode, struct mq_attr __user *u
                return __audit_mq_open(oflag, mode, u_attr);
        return 0;
 }
-static inline int audit_mq_timedsend(mqd_t mqdes, size_t msg_len, unsigned int msg_prio, const struct timespec __user *u_abs_timeout)
+static inline void audit_mq_sendrecv(mqd_t mqdes, size_t msg_len, unsigned int msg_prio, const struct timespec *abs_timeout)
 {
        if (unlikely(!audit_dummy_context()))
-               return __audit_mq_timedsend(mqdes, msg_len, msg_prio, u_abs_timeout);
-       return 0;
-}
-static inline int audit_mq_timedreceive(mqd_t mqdes, size_t msg_len, unsigned int __user *u_msg_prio, const struct timespec __user *u_abs_timeout)
-{
-       if (unlikely(!audit_dummy_context()))
-               return __audit_mq_timedreceive(mqdes, msg_len, u_msg_prio, u_abs_timeout);
-       return 0;
+               __audit_mq_sendrecv(mqdes, msg_len, msg_prio, abs_timeout);
 }
 static inline void audit_mq_notify(mqd_t mqdes, const struct sigevent *notification)
 {
@@ -550,8 +542,7 @@ extern int audit_signals;
 #define audit_sockaddr(len, addr) ({ 0; })
 #define audit_set_macxattr(n) do { ; } while (0)
 #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_sendrecv(d,l,p,t) ((void)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; })

diff --git a/ipc/mqueue.c b/ipc/mqueue.c
index e7b2f68..192da80 100644 (file)
--- a/ipc/mqueue.c
+++ b/ipc/mqueue.c
@@ -524,31 +524,27 @@ static void __do_notify(struct mqueue_inode_info *info)
        wake_up(&info->wait_q);
 }
 
-static long prepare_timeout(const struct timespec __user *u_arg)
+static long prepare_timeout(struct timespec *p)
 {
-       struct timespec ts, nowts;
+       struct timespec nowts;
        long timeout;
 
-       if (u_arg) {
-               if (unlikely(copy_from_user(&ts, u_arg,
-                                       sizeof(struct timespec))))
-                       return -EFAULT;
-
-               if (unlikely(ts.tv_nsec < 0 || ts.tv_sec < 0
-                       || ts.tv_nsec >= NSEC_PER_SEC))
+       if (p) {
+               if (unlikely(p->tv_nsec < 0 || p->tv_sec < 0
+                       || p->tv_nsec >= NSEC_PER_SEC))
                        return -EINVAL;
                nowts = CURRENT_TIME;
                /* first subtract as jiffies can't be too big */
-               ts.tv_sec -= nowts.tv_sec;
-               if (ts.tv_nsec < nowts.tv_nsec) {
-                       ts.tv_nsec += NSEC_PER_SEC;
-                       ts.tv_sec--;
+               p->tv_sec -= nowts.tv_sec;
+               if (p->tv_nsec < nowts.tv_nsec) {
+                       p->tv_nsec += NSEC_PER_SEC;
+                       p->tv_sec--;
                }
-               ts.tv_nsec -= nowts.tv_nsec;
-               if (ts.tv_sec < 0)
+               p->tv_nsec -= nowts.tv_nsec;
+               if (p->tv_sec < 0)
                        return 0;
 
-               timeout = timespec_to_jiffies(&ts) + 1;
+               timeout = timespec_to_jiffies(p) + 1;
        } else
                return MAX_SCHEDULE_TIMEOUT;
 
@@ -829,17 +825,22 @@ asmlinkage long sys_mq_timedsend(mqd_t mqdes, const char __user *u_msg_ptr,
        struct ext_wait_queue *receiver;
        struct msg_msg *msg_ptr;
        struct mqueue_inode_info *info;
+       struct timespec ts, *p = NULL;
        long timeout;
        int ret;
 
-       ret = audit_mq_timedsend(mqdes, msg_len, msg_prio, u_abs_timeout);
-       if (ret != 0)
-               return ret;
+       if (u_abs_timeout) {
+               if (copy_from_user(&ts, u_abs_timeout, 
+                                       sizeof(struct timespec)))
+                       return -EFAULT;
+               p = &ts;
+       }
 
        if (unlikely(msg_prio >= (unsigned long) MQ_PRIO_MAX))
                return -EINVAL;
 
-       timeout = prepare_timeout(u_abs_timeout);
+       audit_mq_sendrecv(mqdes, msg_len, msg_prio, p);
+       timeout = prepare_timeout(p);
 
        ret = -EBADF;
        filp = fget(mqdes);
@@ -918,12 +919,17 @@ asmlinkage ssize_t sys_mq_timedreceive(mqd_t mqdes, char __user *u_msg_ptr,
        struct inode *inode;
        struct mqueue_inode_info *info;
        struct ext_wait_queue wait;
+       struct timespec ts, *p = NULL;
 
-       ret = audit_mq_timedreceive(mqdes, msg_len, u_msg_prio, u_abs_timeout);
-       if (ret != 0)
-               return ret;
+       if (u_abs_timeout) {
+               if (copy_from_user(&ts, u_abs_timeout, 
+                                       sizeof(struct timespec)))
+                       return -EFAULT;
+               p = &ts;
+       }
 
-       timeout = prepare_timeout(u_abs_timeout);
+       audit_mq_sendrecv(mqdes, msg_len, 0, p);
+       timeout = prepare_timeout(p);
 
        ret = -EBADF;
        filp = fget(mqdes);

diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 3ece960..140c474 100644 (file)
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -131,14 +131,6 @@ struct audit_aux_data_mq_open {
        struct mq_attr          attr;
 };
 
-struct audit_aux_data_mq_sendrecv {
-       struct audit_aux_data   d;
-       mqd_t                   mqdes;
-       size_t                  msg_len;
-       unsigned int            msg_prio;
-       struct timespec         abs_timeout;
-};
-
 struct audit_aux_data_execve {
        struct audit_aux_data   d;
        int argc;
@@ -244,6 +236,12 @@ struct audit_context {
                        mqd_t                   mqdes;
                        int                     sigev_signo;
                } mq_notify;
+               struct {
+                       mqd_t                   mqdes;
+                       size_t                  msg_len;
+                       unsigned int            msg_prio;
+                       struct timespec         abs_timeout;
+               } mq_sendrecv;
        };
 
 #if AUDIT_DEBUG
@@ -1265,6 +1263,16 @@ static void show_special(struct audit_context *context, int *call_panic)
                                return;
                }
                break; }
+       case AUDIT_MQ_SENDRECV: {
+               audit_log_format(ab,
+                       "mqdes=%d msg_len=%zd msg_prio=%u "
+                       "abs_timeout_sec=%ld abs_timeout_nsec=%ld",
+                       context->mq_sendrecv.mqdes,
+                       context->mq_sendrecv.msg_len,
+                       context->mq_sendrecv.msg_prio,
+                       context->mq_sendrecv.abs_timeout.tv_sec,
+                       context->mq_sendrecv.abs_timeout.tv_nsec);
+               break; }
        case AUDIT_MQ_NOTIFY: {
                audit_log_format(ab, "mqdes=%d sigev_signo=%d",
                                context->mq_notify.mqdes,
@@ -1370,15 +1378,6 @@ static void audit_log_exit(struct audit_context *context, struct task_struct *ts
                                axi->attr.mq_curmsgs);
                        break; }
 
-               case AUDIT_MQ_SENDRECV: {
-                       struct audit_aux_data_mq_sendrecv *axi = (void *)aux;
-                       audit_log_format(ab,
-                               "mqdes=%d msg_len=%zd msg_prio=%u "
-                               "abs_timeout_sec=%ld abs_timeout_nsec=%ld",
-                               axi->mqdes, axi->msg_len, axi->msg_prio,
-                               axi->abs_timeout.tv_sec, axi->abs_timeout.tv_nsec);
-                       break; }
-
                case AUDIT_EXECVE: {
                        struct audit_aux_data_execve *axi = (void *)aux;
                        audit_log_execve_info(context, &ab, axi);
@@ -2171,97 +2170,29 @@ int __audit_mq_open(int oflag, mode_t mode, struct mq_attr __user *u_attr)
 }
 
 /**
- * __audit_mq_timedsend - record audit data for a POSIX MQ timed send
+ * __audit_mq_sendrecv - record audit data for a POSIX MQ timed send/receive
  * @mqdes: MQ descriptor
  * @msg_len: Message length
  * @msg_prio: Message priority
- * @u_abs_timeout: Message timeout in absolute time
- *
- * Returns 0 for success or NULL context or < 0 on error.
- */
-int __audit_mq_timedsend(mqd_t mqdes, size_t msg_len, unsigned int msg_prio,
-                       const struct timespec __user *u_abs_timeout)
-{
-       struct audit_aux_data_mq_sendrecv *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_abs_timeout != NULL) {
-               if (copy_from_user(&ax->abs_timeout, u_abs_timeout, sizeof(ax->abs_timeout))) {
-                       kfree(ax);
-                       return -EFAULT;
-               }
-       } else
-               memset(&ax->abs_timeout, 0, sizeof(ax->abs_timeout));
-
-       ax->mqdes = mqdes;
-       ax->msg_len = msg_len;
-       ax->msg_prio = msg_prio;
-
-       ax->d.type = AUDIT_MQ_SENDRECV;
-       ax->d.next = context->aux;
-       context->aux = (void *)ax;
-       return 0;
-}
-
-/**
- * __audit_mq_timedreceive - record audit data for a POSIX MQ timed receive
- * @mqdes: MQ descriptor
- * @msg_len: Message length
- * @u_msg_prio: Message priority
- * @u_abs_timeout: Message timeout in absolute time
+ * @abs_timeout: Message timeout in absolute time
  *
- * Returns 0 for success or NULL context or < 0 on error.
  */
-int __audit_mq_timedreceive(mqd_t mqdes, size_t msg_len,
-                               unsigned int __user *u_msg_prio,
-                               const struct timespec __user *u_abs_timeout)
+void __audit_mq_sendrecv(mqd_t mqdes, size_t msg_len, unsigned int msg_prio,
+                       const struct timespec *abs_timeout)
 {
-       struct audit_aux_data_mq_sendrecv *ax;
        struct audit_context *context = current->audit_context;
+       struct timespec *p = &context->mq_sendrecv.abs_timeout;
 
-       if (!audit_enabled)
-               return 0;
-
-       if (likely(!context))
-               return 0;
-
-       ax = kmalloc(sizeof(*ax), GFP_ATOMIC);
-       if (!ax)
-               return -ENOMEM;
-
-       if (u_msg_prio != NULL) {
-               if (get_user(ax->msg_prio, u_msg_prio)) {
-                       kfree(ax);
-                       return -EFAULT;
-               }
-       } else
-               ax->msg_prio = 0;
-
-       if (u_abs_timeout != NULL) {
-               if (copy_from_user(&ax->abs_timeout, u_abs_timeout, sizeof(ax->abs_timeout))) {
-                       kfree(ax);
-                       return -EFAULT;
-               }
-       } else
-               memset(&ax->abs_timeout, 0, sizeof(ax->abs_timeout));
+       if (abs_timeout)
+               memcpy(p, abs_timeout, sizeof(struct timespec));
+       else
+               memset(p, 0, sizeof(struct timespec));
 
-       ax->mqdes = mqdes;
-       ax->msg_len = msg_len;
+       context->mq_sendrecv.mqdes = mqdes;
+       context->mq_sendrecv.msg_len = msg_len;
+       context->mq_sendrecv.msg_prio = msg_prio;
 
-       ax->d.type = AUDIT_MQ_SENDRECV;
-       ax->d.next = context->aux;
-       context->aux = (void *)ax;
-       return 0;
+       context->type = AUDIT_MQ_SENDRECV;
 }
 
 /**