From: Dan Carpenter <dan.carpenter@oracle.com>
To: Jens Axboe <axboe@kernel.dk>
Cc: Pavel Begunkov <asml.silence@gmail.com>,
linux-fsdevel@vger.kernel.org, io-uring@vger.kernel.org,
kernel-janitors@vger.kernel.org
Subject: [PATCH] io_uring: fix a use after free in io_async_task_func()
Date: Wed, 8 Jul 2020 21:47:11 +0300 [thread overview]
Message-ID: <20200708184711.GA31157@mwanda> (raw)
The "apoll" variable is freed and then used on the next line. We need
to move the free down a few lines.
Fixes: 0be0b0e33b0b ("io_uring: simplify io_async_task_func()")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
fs/io_uring.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 70828e2470e2..f2993070a9e8 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -4652,12 +4652,13 @@ static void io_async_task_func(struct callback_head *cb)
/* restore ->work in case we need to retry again */
if (req->flags & REQ_F_WORK_INITIALIZED)
memcpy(&req->work, &apoll->work, sizeof(req->work));
- kfree(apoll);
if (!READ_ONCE(apoll->poll.canceled))
__io_req_task_submit(req);
else
__io_req_task_cancel(req, -ECANCELED);
+
+ kfree(apoll);
}
static int io_async_wake(struct wait_queue_entry *wait, unsigned mode, int sync,
--
2.27.0
next reply other threads:[~2020-07-08 18:49 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-08 18:47 Dan Carpenter [this message]
2020-07-08 19:01 ` [PATCH] io_uring: fix a use after free in io_async_task_func() Pavel Begunkov
2020-07-08 19:14 ` Jens Axboe
2020-07-08 19:15 ` Jens Axboe
2020-07-08 19:28 ` Pavel Begunkov
2020-07-08 19:56 ` Matthew Wilcox
2020-07-09 9:47 ` Pavel Begunkov
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