ion: Fix use after free during ION_IOC_ALLOC
If a user happens to call ION_IOC_FREE during an ION_IOC_ALLOC
on the just allocated id, and the copy_to_user fails, the cleanup
code will attempt to free an already freed handle.
This adds a wrapper for ion_alloc that adds an ion_handle_get to
avoid this.
Signed-off-by: Daniel Rosenberg <drosen@google.com>
Signed-off-by: Dennis Cagle <d-cagle@codeaurora.org>
Signed-off-by: Patrick Daly <pdaly@codeaurora.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/staging/android/ion/ion-ioctl.c b/drivers/staging/android/ion/ion-ioctl.c
index e359685..f260e0e 100644
--- a/drivers/staging/android/ion/ion-ioctl.c
+++ b/drivers/staging/android/ion/ion-ioctl.c
@@ -96,10 +96,10 @@
{
struct ion_handle *handle;
- handle = ion_alloc(client, data.allocation.len,
- data.allocation.align,
- data.allocation.heap_id_mask,
- data.allocation.flags);
+ handle = __ion_alloc(client, data.allocation.len,
+ data.allocation.align,
+ data.allocation.heap_id_mask,
+ data.allocation.flags, true);
if (IS_ERR(handle))
return PTR_ERR(handle);
@@ -174,10 +174,14 @@
if (dir & _IOC_READ) {
if (copy_to_user((void __user *)arg, &data, _IOC_SIZE(cmd))) {
- if (cleanup_handle)
+ if (cleanup_handle) {
ion_free(client, cleanup_handle);
+ ion_handle_put(cleanup_handle);
+ }
return -EFAULT;
}
}
+ if (cleanup_handle)
+ ion_handle_put(cleanup_handle);
return ret;
}
diff --git a/drivers/staging/android/ion/ion.c b/drivers/staging/android/ion/ion.c
index aac9b38..4f76921 100644
--- a/drivers/staging/android/ion/ion.c
+++ b/drivers/staging/android/ion/ion.c
@@ -401,9 +401,9 @@
return 0;
}
-struct ion_handle *ion_alloc(struct ion_client *client, size_t len,
- size_t align, unsigned int heap_id_mask,
- unsigned int flags)
+struct ion_handle *__ion_alloc(struct ion_client *client, size_t len,
+ size_t align, unsigned int heap_id_mask,
+ unsigned int flags, bool grab_handle)
{
struct ion_handle *handle;
struct ion_device *dev = client->dev;
@@ -453,6 +453,8 @@
return handle;
mutex_lock(&client->lock);
+ if (grab_handle)
+ ion_handle_get(handle);
ret = ion_handle_add(client, handle);
mutex_unlock(&client->lock);
if (ret) {
@@ -462,6 +464,13 @@
return handle;
}
+
+struct ion_handle *ion_alloc(struct ion_client *client, size_t len,
+ size_t align, unsigned int heap_id_mask,
+ unsigned int flags)
+{
+ return __ion_alloc(client, len, align, heap_id_mask, flags, false);
+}
EXPORT_SYMBOL(ion_alloc);
void ion_free_nolock(struct ion_client *client,
diff --git a/drivers/staging/android/ion/ion.h b/drivers/staging/android/ion/ion.h
index 93dafb4..cfa50df 100644
--- a/drivers/staging/android/ion/ion.h
+++ b/drivers/staging/android/ion/ion.h
@@ -109,6 +109,10 @@
size_t align, unsigned int heap_id_mask,
unsigned int flags);
+struct ion_handle *__ion_alloc(struct ion_client *client, size_t len,
+ size_t align, unsigned int heap_id_mask,
+ unsigned int flags, bool grab_handle);
+
/**
* ion_free - free a handle
* @client: the client