Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Wed, 9 Nov 2022 22:05:07 -0800
From:   Luis Chamberlain <mcgrof@kernel.org>
To:     Miaoqian Lin <linmq006@gmail.com>
Cc:     Dmitry Torokhov <dmitry.torokhov@gmail.com>,
        linux-modules@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] module: Fix NULL vs IS_ERR checking for
 module_get_next_page
Message-ID: <Y2yUkxeBEF40olMD@bombadil.infradead.org>
References: <20221110025834.1624394-1-linmq006@gmail.com>
 <Y2x5a1YVbvmqrK9O@bombadil.infradead.org>
 <ffda7120-c2aa-d093-a2a5-f5d169c7651e@gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <ffda7120-c2aa-d093-a2a5-f5d169c7651e@gmail.com>
Sender: Luis Chamberlain <mcgrof@infradead.org>
Precedence: bulk

On Thu, Nov 10, 2022 at 12:18:50PM +0800, Miaoqian Lin wrote:
> Hi,
> 
> On 2022/11/10 12:09, Luis Chamberlain wrote:
> > On Thu, Nov 10, 2022 at 06:58:34AM +0400, Miaoqian Lin wrote:
> >> The module_get_next_page() function return error pointers on error
> >> instead of NULL.
> >> Use IS_ERR() to check the return value to fix this.
> >>
> >> Fixes: b1ae6dc41eaa ("module: add in-kernel support for decompressing")
> >> Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
> >> ---
> > Thanks queued up. How did you find out? Just code inspection? I see
> > chances are low of this triggering, but just curious how you found it.
> I found this by static analysis, specifically, I obtained functions that return error pointers and
> inspected whether their callers followed the correct specification.

Which one did you use?

  Luis