report errors in /proc/*/*map* sanely, CVE-2011-1020

[linux-flexiantxendom0-natty.git] / fs / proc / task_nommu.c

diff --git a/fs/proc/task_nommu.c b/fs/proc/task_nommu.c
index b535d3e..980de54 100644 (file)
--- a/fs/proc/task_nommu.c
+++ b/fs/proc/task_nommu.c
@@ -199,13 +199,13 @@ static void *m_start(struct seq_file *m, loff_t *pos)
        /* pin the task and mm whilst we play with them */
        priv->task = get_pid_task(priv->pid, PIDTYPE_PID);
        if (!priv->task)
-               return NULL;
+               return ERR_PTR(-ESRCH);
 
        mm = mm_for_maps(priv->task);
-       if (!mm) {
+       if (!mm || IS_ERR(mm)) {
                put_task_struct(priv->task);
                priv->task = NULL;
-               return NULL;
+               return mm;
        }
        down_read(&mm->mmap_sem);