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Date:   Thu, 01 Sep 2022 13:14:02 +0530
From:   Siddh Raman Pant <code@siddh.me>
To:     "Elliott, Robert (Servers)" <elliott@hpe.com>
Cc:     "palmer@rivosinc.com" <palmer@rivosinc.com>,
        "davem@davemloft.net" <davem@davemloft.net>,
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        "kuba@kernel.org" <kuba@kernel.org>,
        "linux-bluetooth@vger.kernel.org" <linux-bluetooth@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "linux@rivosinc.com" <linux@rivosinc.com>,
        "luiz.dentz@gmail.com" <luiz.dentz@gmail.com>,
        "marcel@holtmann.org" <marcel@holtmann.org>,
        "netdev@vger.kernel.org" <netdev@vger.kernel.org>,
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Message-ID: <182f801c979.751199c4530197.7043811006670900472@siddh.me>
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References: <20220812055249.8037-1-palmer@rivosinc.com>
 <20220825110108.157350-1-code@siddh.me> <MW5PR84MB184223FFE931E4B121AF7AC0AB769@MW5PR84MB1842.NAMPRD84.PROD.OUTLOOK.COM>
Subject: RE: [PATCH] Bluetooth: L2CAP: Elide a string overflow warning
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On Tue, 30 Aug 2022 01:21:58 +0530  Elliott, Robert (Servers)  wrote:
> > -----Original Message-----
> > From: Siddh Raman Pant code@siddh.me>
> > Sent: Thursday, August 25, 2022 6:01 AM
> > To: palmer@rivosinc.com
> > Cc: davem@davemloft.net; edumazet@google.com; johan.hedberg@gmail.com;
> > kuba@kernel.org; linux-bluetooth@vger.kernel.org; linux-
> > kernel@vger.kernel.org; linux@rivosinc.com; luiz.dentz@gmail.com;
> > marcel@holtmann.org; netdev@vger.kernel.org; pabeni@redhat.com
> > Subject: Re: [PATCH] Bluetooth: L2CAP: Elide a string overflow warning
> > 
> > On Fri, 12 Aug 2022 11:22:49 +0530  Palmer Dabbelt  wrote:
> > > From: Palmer Dabbelt palmer@rivosinc.com>
> > >
> > > Without this I get a string op warning related to copying from a
> > > possibly NULL pointer.  I think the warning is spurious, but it's
> > > tripping up allmodconfig.
> > 
> > I think it is not spurious, and is due to the following commit:
> > d0be8347c623 ("Bluetooth: L2CAP: Fix use-after-free caused by l2cap_chan_put")
> 
> That commit was OK - it added an "if (!c) continue" to handle if
> the value c is changed to NULL.
>  
> > The following commit fixes a similar problem (added the NULL check on line
> > 1996):
> > 332f1795ca20 ("Bluetooth: L2CAP: Fix l2cap_global_chan_by_psm regression")
> 
> That commit wiped out the "if (!c) continue" path escape clause
> from the previous patch, introducing a path back to code that
> doesn't check for NULL:

You are correct, thanks for clarifying. Sorry for getting it reversed.

So I think this patch can be modified to just introduce back the escape
clause rather than having an extra indentation.

Thanks,
Siddh