From e5313c141b49c1b1af43d1ca81398185d66ad1a6 Mon Sep 17 00:00:00 2001 From: Omar Sandoval Date: Wed, 20 Sep 2017 14:24:34 -0700 Subject: [PATCH] loop: remove union of use_aio and ref in struct loop_cmd When the request is completed, lo_complete_rq() checks cmd->use_aio. However, if this is in fact an aio request, cmd->use_aio will have already been reused as cmd->ref by lo_rw_aio*. Fix it by not using a union. On x86_64, there's a hole after the union anyways, so this doesn't make struct loop_cmd any bigger. Fixes: 92d773324b7e ("block/loop: fix use after free") Signed-off-by: Omar Sandoval Signed-off-by: Jens Axboe --- drivers/block/loop.h | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/drivers/block/loop.h b/drivers/block/loop.h index f68c1d50802f..1f3956702993 100644 --- a/drivers/block/loop.h +++ b/drivers/block/loop.h @@ -67,10 +67,8 @@ struct loop_device { struct loop_cmd { struct kthread_work work; struct request *rq; - union { - bool use_aio; /* use AIO interface to handle I/O */ - atomic_t ref; /* only for aio */ - }; + bool use_aio; /* use AIO interface to handle I/O */ + atomic_t ref; /* only for aio */ long ret; struct kiocb iocb; struct bio_vec *bvec; -- 2.20.1