diff options
| -rw-r--r-- | drivers/staging/android/ion/ion.c | 17 |
1 files changed, 14 insertions, 3 deletions
diff --git a/drivers/staging/android/ion/ion.c b/drivers/staging/android/ion/ion.c index 403df8bf4b48..806e9b30b9dc 100644 --- a/drivers/staging/android/ion/ion.c +++ b/drivers/staging/android/ion/ion.c @@ -15,6 +15,7 @@ * */ +#include <linux/atomic.h> #include <linux/device.h> #include <linux/err.h> #include <linux/file.h> @@ -305,6 +306,16 @@ static void ion_handle_get(struct ion_handle *handle) kref_get(&handle->ref); } +/* Must hold the client lock */ +static struct ion_handle *ion_handle_get_check_overflow( + struct ion_handle *handle) +{ + if (atomic_read(&handle->ref.refcount) + 1 == 0) + return ERR_PTR(-EOVERFLOW); + ion_handle_get(handle); + return handle; +} + int ion_handle_put_nolock(struct ion_handle *handle) { return kref_put(&handle->ref, ion_handle_destroy); @@ -347,9 +358,9 @@ struct ion_handle *ion_handle_get_by_id_nolock(struct ion_client *client, handle = idr_find(&client->idr, id); if (handle) - ion_handle_get(handle); + return ion_handle_get_check_overflow(handle); - return handle ? handle : ERR_PTR(-EINVAL); + return ERR_PTR(-EINVAL); } static bool ion_handle_validate(struct ion_client *client, @@ -1110,7 +1121,7 @@ struct ion_handle *ion_import_dma_buf(struct ion_client *client, /* if a handle exists for this buffer just take a reference to it */ handle = ion_handle_lookup(client, buffer); if (!IS_ERR(handle)) { - ion_handle_get(handle); + handle = ion_handle_get_check_overflow(handle); mutex_unlock(&client->lock); goto end; } |