Re: [PATCH v2 2/2] fs: avoid fdput() after failed fdget() in kernel_read_file_from_fd()

From: Scott Branden <scott.branden@broadcom.com>
To: Luis Chamberlain <mcgrof@kernel.org>,
	Al Viro <viro@zeniv.linux.org.uk>,
	Kees Cook <keescook@chromium.org>,
	Mimi Zohar <zohar@linux.vnet.ibm.com>,
	linux-security-module <linux-security-module@vger.kernel.org>,
	James Morris <jmorris@namei.org>,
	"Serge E. Hallyn" <serge@hallyn.com>,
	Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Martin KaFai Lau <kafai@fb.com>, Song Liu <songliubraving@fb.com>,
	Yonghong Song <yhs@fb.com>, Andrii Nakryiko <andriin@fb.com>,
	John Fastabend <john.fastabend@gmail.com>,
	KP Singh <kpsingh@chromium.org>
Cc: Shuah Khan <skhan@linuxfoundation.org>,
	Jens Axboe <axboe@kernel.dk>,
	Linux FS Devel <linux-fsdevel@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2 2/2] fs: avoid fdput() after failed fdget() in kernel_read_file_from_fd()
Date: Fri, 22 May 2020 14:59:57 -0700	[thread overview]
Message-ID: <2d298b41-ab6f-5834-19d2-7d3739470b5f@broadcom.com> (raw)
In-Reply-To: <CAB=NE6WdYcURTxNLngMk3+JQfNHG2MX1oE_Mv08G5zcw=mPOyw@mail.gmail.com>

Hi Luis,

On 2020-05-13 7:19 a.m., Luis Chamberlain wrote:
> On Wed, May 13, 2020 at 7:13 AM Luis Chamberlain <mcgrof@kernel.org> wrote:
>> On Wed, May 13, 2020 at 06:49:50AM +0100, Al Viro wrote:
>>> On Tue, May 12, 2020 at 01:43:05PM -0600, Shuah Khan wrote:
>>>> diff --git a/fs/exec.c b/fs/exec.c
>>>> index 06b4c550af5d..ea24bdce939d 100644
>>>> --- a/fs/exec.c
>>>> +++ b/fs/exec.c
>>>> @@ -1021,8 +1021,8 @@ int kernel_read_file_from_fd(int fd, void **buf, loff_t *size, loff_t max_size,
>>>>              goto out;
>>>>
>>>>      ret = kernel_read_file(f.file, buf, size, max_size, id);
>>>> -out:
>>>>      fdput(f);
>>>> +out:
>>>>      return ret;
>>> Incidentally, why is that thing exported?
>> Both kernel_read_file_from_fd() and kernel_read_file() are exported
>> because they have users, however kernel_read_file() only has security
>> stuff as a user. Do we want to get rid of the lsm hook for it?
> Alright, yeah just the export needs to be removed. I have a patch
> series dealing with these callers so will add it to my queue.
When will these changes make it into linux-next?
It is difficult for me to complete my patch series without these other 
misc. changes in place.
>
>    Luis
Regards,
  Scott