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>

1 files changed, 22 insertions, 24 deletions

diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 4819f3711973..c2e43ebb1b68 100644
--- 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;
 }