If the copy_to_user() fails we should unlock and return directly without updating "cnt". Also the return value should be -EFAULT instead of the number of bytes remaining. Fixes: 02b23803c6af ("staging: android: ion: Add ioctl to query available heaps") Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> --- v2: a more complete fix diff --git a/drivers/staging/android/ion/ion.c b/drivers/staging/android/ion/ion.c index 396ded5..209a8f7 100644 --- a/drivers/staging/android/ion/ion.c +++ b/drivers/staging/android/ion/ion.c @@ -1187,8 +1187,10 @@ int ion_query_heaps(struct ion_client *client, struct ion_heap_query *query) hdata.type = heap->type; hdata.heap_id = heap->id; - ret = copy_to_user(&buffer[cnt], - &hdata, sizeof(hdata)); + if (copy_to_user(&buffer[cnt], &hdata, sizeof(hdata))) { + ret = -EFAULT; + goto out; + } cnt++; if (cnt >= max_cnt) -- To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html