futex: Do not leak robust list to unprivileged process

[linux-flexiantxendom0-3.2.10.git] / kernel / relay.c

diff --git a/kernel/relay.c b/kernel/relay.c
index 4268287..ab56a17 100644 (file)
--- a/kernel/relay.c
+++ b/kernel/relay.c
@@ -15,7 +15,7 @@
 #include <linux/errno.h>
 #include <linux/stddef.h>
 #include <linux/slab.h>
-#include <linux/module.h>
+#include <linux/export.h>
 #include <linux/string.h>
 #include <linux/relay.h>
 #include <linux/vmalloc.h>
@@ -70,17 +70,10 @@ static const struct vm_operations_struct relay_file_mmap_ops = {
  */
 static struct page **relay_alloc_page_array(unsigned int n_pages)
 {
-       struct page **array;
-       size_t pa_size = n_pages * sizeof(struct page *);
-
-       if (pa_size > PAGE_SIZE) {
-               array = vmalloc(pa_size);
-               if (array)
-                       memset(array, 0, pa_size);
-       } else {
-               array = kzalloc(pa_size, GFP_KERNEL);
-       }
-       return array;
+       const size_t pa_size = n_pages * sizeof(struct page *);
+       if (pa_size > PAGE_SIZE)
+               return vzalloc(pa_size);
+       return kzalloc(pa_size, GFP_KERNEL);
 }
 
 /*
@@ -171,10 +164,14 @@ depopulate:
  */
 static struct rchan_buf *relay_create_buf(struct rchan *chan)
 {
-       struct rchan_buf *buf = kzalloc(sizeof(struct rchan_buf), GFP_KERNEL);
-       if (!buf)
+       struct rchan_buf *buf;
+
+       if (chan->n_subbufs > UINT_MAX / sizeof(size_t *))
                return NULL;
 
+       buf = kzalloc(sizeof(struct rchan_buf), GFP_KERNEL);
+       if (!buf)
+               return NULL;
        buf->padding = kmalloc(chan->n_subbufs * sizeof(size_t *), GFP_KERNEL);
        if (!buf->padding)
                goto free_buf;
@@ -309,7 +306,7 @@ static void buf_unmapped_default_callback(struct rchan_buf *buf,
  */
 static struct dentry *create_buf_file_default_callback(const char *filename,
                                                       struct dentry *parent,
-                                                      int mode,
+                                                      umode_t mode,
                                                       struct rchan_buf *buf,
                                                       int *is_global)
 {
@@ -539,7 +536,7 @@ static int __cpuinit relay_hotcpu_callback(struct notifier_block *nb,
                                        "relay_hotcpu_callback: cpu %d buffer "
                                        "creation failed\n", hotcpu);
                                mutex_unlock(&relay_channels_mutex);
-                               return NOTIFY_BAD;
+                               return notifier_from_errno(-ENOMEM);
                        }
                }
                mutex_unlock(&relay_channels_mutex);
@@ -581,6 +578,8 @@ struct rchan *relay_open(const char *base_filename,
 
        if (!(subbuf_size && n_subbufs))
                return NULL;
+       if (subbuf_size > UINT_MAX / n_subbufs)
+               return NULL;
 
        chan = kzalloc(sizeof(struct rchan), GFP_KERNEL);
        if (!chan)