From: Alan Stern <stern@rowland.harvard.edu>
To: Hangyu Hua <hbh25y@gmail.com>
Cc: balbi@kernel.org, gregkh@linuxfoundation.org, axboe@kernel.dk,
jj251510319013@gmail.com, dan.carpenter@oracle.com,
linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3 2/2] usb: gadget: clear related members when goto fail
Date: Fri, 31 Dec 2021 10:57:41 -0500 [thread overview]
Message-ID: <Yc8odYb41iNuQ16J@rowland.harvard.edu> (raw)
In-Reply-To: <CAOo-nLLpNfHzrOyF4P0XvFK1h+J+aZqGL+AqmZP2PG6C=rcFjg@mail.gmail.com>
On Fri, Dec 31, 2021 at 10:31:51AM +0800, Hangyu Hua wrote:
> On 2021/12/31 上午3:46, Alan Stern wrote:
> >> @@ -1892,7 +1895,12 @@ dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
> >> }
> >> return value;
> >>
> >> +fail2:
> >> + dev->dev = NULL;
> >> +fail1:
> >> + dev->hs_config = NULL;
> >
> > It is not necessary to have all these different statement labels. You
> > can simply have "fail:" clear all three pointers.
> I don't think so. It is not necessary to clean all three pointers if
> some of them aren't kbuf. I think it may be better to keep their own
> pointers.
If the pointers aren't set to a region inside kbuf then they are
meaningless. There is no reason to keep the old values. It is better
to avoid multiple unnecessary statement labels.
Alan Stern
next prev parent reply other threads:[~2021-12-31 15:57 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-30 5:11 [PATCH v3 0/2] usb: gadget: use after free in dev_config Hangyu Hua
2021-12-30 5:11 ` [PATCH v3 1/2] usb: gadget: don't release an existing dev->buf Hangyu Hua
2021-12-30 5:11 ` [PATCH v3 2/2] usb: gadget: clear related members when goto fail Hangyu Hua
2021-12-30 19:46 ` Alan Stern
2021-12-30 19:50 ` Alan Stern
2021-12-31 2:31 ` Hangyu Hua
2021-12-31 15:57 ` Alan Stern [this message]
2021-12-31 16:15 ` Hangyu Hua
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