don't reallocate buffer in every audit_sockaddr()

No need to do that more than once per process lifetime; allocating/freeing
on each sendto/accept/etc. is bloody pointless.

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

diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 4819f37..c2e43eb 100644 (file)
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -174,12 +174,6 @@ struct audit_aux_data_socketcall {
        unsigned long           args[0];
 };
 
-struct audit_aux_data_sockaddr {
-       struct audit_aux_data   d;
-       int                     len;
-       char                    a[0];
-};
-
 struct audit_aux_data_fd_pair {
        struct  audit_aux_data d;
        int     fd[2];
@@ -234,7 +228,8 @@ struct audit_context {
        struct audit_context *previous; /* For nested syscalls */
        struct audit_aux_data *aux;
        struct audit_aux_data *aux_pids;
-
+       struct sockaddr_storage *sockaddr;
+       size_t sockaddr_len;
                                /* Save things to print about task_struct */
        pid_t               pid, ppid;
        uid_t               uid, euid, suid, fsuid;
@@ -921,6 +916,7 @@ static inline void audit_free_context(struct audit_context *context)
                free_tree_refs(context);
                audit_free_aux(context);
                kfree(context->filterkey);
+               kfree(context->sockaddr);
                kfree(context);
                context  = previous;
        } while (context);
@@ -1383,13 +1379,6 @@ static void audit_log_exit(struct audit_context *context, struct task_struct *ts
                                audit_log_format(ab, " a%d=%lx", i, axs->args[i]);
                        break; }
 
-               case AUDIT_SOCKADDR: {
-                       struct audit_aux_data_sockaddr *axs = (void *)aux;
-
-                       audit_log_format(ab, "saddr=");
-                       audit_log_n_hex(ab, axs->a, axs->len);
-                       break; }
-
                case AUDIT_FD_PAIR: {
                        struct audit_aux_data_fd_pair *axs = (void *)aux;
                        audit_log_format(ab, "fd0=%d fd1=%d", axs->fd[0], axs->fd[1]);
@@ -1421,6 +1410,16 @@ static void audit_log_exit(struct audit_context *context, struct task_struct *ts
                audit_log_end(ab);
        }
 
+       if (context->sockaddr_len) {
+               ab = audit_log_start(context, GFP_KERNEL, AUDIT_SOCKADDR);
+               if (ab) {
+                       audit_log_format(ab, "saddr=");
+                       audit_log_n_hex(ab, (void *)context->sockaddr,
+                                       context->sockaddr_len);
+                       audit_log_end(ab);
+               }
+       }
+
        for (aux = context->aux_pids; aux; aux = aux->next) {
                struct audit_aux_data_pids *axs = (void *)aux;
 
@@ -1689,6 +1688,7 @@ void audit_syscall_exit(int valid, long return_code)
                context->aux_pids = NULL;
                context->target_pid = 0;
                context->target_sid = 0;
+               context->sockaddr_len = 0;
                kfree(context->filterkey);
                context->filterkey = NULL;
                tsk->audit_context = context;
@@ -2468,22 +2468,20 @@ int __audit_fd_pair(int fd1, int fd2)
  */
 int audit_sockaddr(int len, void *a)
 {
-       struct audit_aux_data_sockaddr *ax;
        struct audit_context *context = current->audit_context;
 
        if (likely(!context || context->dummy))
                return 0;
 
-       ax = kmalloc(sizeof(*ax) + len, GFP_KERNEL);
-       if (!ax)
-               return -ENOMEM;
-
-       ax->len = len;
-       memcpy(ax->a, a, len);
+       if (!context->sockaddr) {
+               void *p = kmalloc(sizeof(struct sockaddr_storage), GFP_KERNEL);
+               if (!p)
+                       return -ENOMEM;
+               context->sockaddr = p;
+       }
 
-       ax->d.type = AUDIT_SOCKADDR;
-       ax->d.next = context->aux;
-       context->aux = (void *)ax;
+       context->sockaddr_len = len;
+       memcpy(context->sockaddr, a, len);
        return 0;
 }