From: Felipe Balbi <balbi@kernel.org>
To: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Alan Stern <stern@rowland.harvard.edu>,
Jens Axboe <axboe@kernel.dk>,
Felix Kuehling <Felix.Kuehling@amd.com>,
Andrew Morton <akpm@linux-foundation.org>,
"Gustavo A. R. Silva" <gustavoars@kernel.org>,
Masahiro Yamada <masahiroy@kernel.org>,
Zhang Qilong <zhangqilong3@huawei.com>,
linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
kernel-janitors@vger.kernel.org
Subject: Re: [PATCH] usb: gadget: prevent a ternary sign expansion bug
Date: Thu, 22 Apr 2021 14:03:49 +0300 [thread overview]
Message-ID: <87im4emvhm.fsf@kernel.org> (raw)
In-Reply-To: <YIE7RrBPLWc3XtMg@mwanda>
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Dan Carpenter <dan.carpenter@oracle.com> writes:
> The problem is that "req->actual" is a u32, "req->status" is an int, and
> iocb->ki_complete() takes a long. We would expect that a negative error
> code in "req->status" would translate to a negative long value.
>
> But what actually happens is that because "req->actual" is a u32, the
> error codes is type promoted to a high positive value and then remains
> a positive value when it is cast to long. (No sign expansion).
>
> We can fix this by casting "req->status" to long.
>
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
I'm just going to assume your type promotion rank is correct :-)
Acked-by: Felipe Balbi <balbi@kernel.org>
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balbi
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prev parent reply other threads:[~2021-04-22 11:04 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-22 9:00 [PATCH] usb: gadget: prevent a ternary sign expansion bug Dan Carpenter
2021-04-22 11:03 ` Felipe Balbi [this message]
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