From: Omar Sandoval <osandov@xxxxxx>
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 <osandov@xxxxxx>
---
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;
--
2.14.1
