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Date: Sat, 16 Mar 2024 07:11:20 -0600
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Subject: Re: [PATCH] io_uring: fix uninit-value in io_sendrecv_fail
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To: Edward Adam Davis <eadavis@qq.com>,
 syzbot+f8e9a371388aa62ecab4@syzkaller.appspotmail.com
Cc: asml.silence@gmail.com, io-uring@vger.kernel.org,
 linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com
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 <tencent_6C22CC2079326CC82FB96CD89458E9F6EF0A@qq.com>
From: Jens Axboe <axboe@kernel.dk>
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On 3/16/24 6:42 AM, Edward Adam Davis wrote:
> diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
> index cd9a137ad6ce..3db59fd6f676 100644
> --- a/io_uring/io_uring.c
> +++ b/io_uring/io_uring.c
> @@ -1066,6 +1066,7 @@ static void io_preinit_req(struct io_kiocb *req, struct io_ring_ctx *ctx)
>  	/* not necessary, but safer to zero */
>  	memset(&req->cqe, 0, sizeof(req->cqe));
>  	memset(&req->big_cqe, 0, sizeof(req->big_cqe));
> +	memset(&req->cmd, 0, sizeof(req->cmd));
>  }
>  
>  static void io_flush_cached_locked_reqs(struct io_ring_ctx *ctx,

This will just silence the syzbot report, as the memory is initialized
upfront. But it's not the real fix, as ->done_io could still be recycled
from a previous issue.

-- 
Jens Axboe