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From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Alan Stern <stern@rowland.harvard.edu>
Cc: Chunfeng Yun <chunfeng.yun@mediatek.com>,
	linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org, linux-usb@vger.kernel.org,
	linux-mediatek@lists.infradead.org
Subject: Re: [PATCH] usb: core: buffer: avoid NULL pointer dereferrence
Date: Tue, 26 Apr 2016 16:11:15 -0700	[thread overview]
Message-ID: <20160426231115.GB23273@kroah.com> (raw)
In-Reply-To: <Pine.LNX.4.44L0.1604081120190.2069-100000@iolanthe.rowland.org>

On Fri, Apr 08, 2016 at 11:21:05AM -0400, Alan Stern wrote:
> On Fri, 8 Apr 2016, Greg Kroah-Hartman wrote:
> 
> > On Fri, Apr 08, 2016 at 05:08:03PM +0800, Chunfeng Yun wrote:
> > > NULL pointer dereferrence will happen when class driver
> > > wants to allocate zero length buffer and pool_max[0]
> > > can't be used, so skip reserved pool in this case.
> > 
> > Why would a driver want to allocate a 0 length buffer?  What driver does
> > this?
> > 
> > Shouldn't we fix that issue instead?
> 
> And even if a driver does want to allocate a 0-length buffer, shouldn't 
> the function simply return early instead of running through all its 
> calculations?

Yes it should, Chunfeng, can you fix this patch to do that please.

thanks,

greg k-h

  reply	other threads:[~2016-04-26 23:11 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-04-08  9:08 [PATCH] usb: core: buffer: avoid NULL pointer dereferrence Chunfeng Yun
     [not found] ` <1460106483-24793-1-git-send-email-chunfeng.yun-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>
2016-04-08 14:07   ` Greg Kroah-Hartman
     [not found]     ` <20160408140701.GA3547-U8xfFu+wG4EAvxtiuMwx3w@public.gmane.org>
2016-04-08 15:21       ` Alan Stern
2016-04-26 23:11         ` Greg Kroah-Hartman [this message]
     [not found]           ` <20160426231115.GB23273-U8xfFu+wG4EAvxtiuMwx3w@public.gmane.org>
2016-04-27  1:32             ` chunfeng yun
2016-04-11  3:01     ` chunfeng yun
2016-04-11  5:07       ` Felipe Balbi
2016-04-11  7:16         ` chunfeng yun
2016-04-11  8:24           ` Felipe Balbi
2016-04-11 14:44           ` Alan Stern

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