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;
Message-ID: <0857ddf2-89a9-231b-89da-57cacc7342d5@kernel.dk>
Date:   Mon, 16 Jan 2023 08:50:20 -0700
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux aarch64; rv:102.0) Gecko/20100101
 Thunderbird/102.6.0
Subject: =?UTF-8?Q?Re=3a_=5bregression=5d_Bug=c2=a0216932_-_io=5furing_with_?=
 =?UTF-8?Q?libvirt_cause_kernel_NULL_pointer_dereference_since_6=2e1=2e5?=
Content-Language: en-US
From:   Jens Axboe <axboe@kernel.dk>
To:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc:     Linux regressions mailing list <regressions@lists.linux.dev>,
        "stable@vger.kernel.org" <stable@vger.kernel.org>,
        io-uring@vger.kernel.org, LKML <linux-kernel@vger.kernel.org>,
        "Sergey V." <truesmb@gmail.com>
References: <74347fe1-ac68-2661-500d-b87fab6994f7@leemhuis.info>
 <c5632908-1b0f-af1f-4754-bf1d0027a6dc@kernel.dk>
 <a862915b-66f3-9ad8-77d4-4b9ce7044037@kernel.dk> <Y8VkB6Q2xqeut5N8@kroah.com>
 <e921f92d-52ac-1dc7-7720-c270910c2a2d@kernel.dk>
In-Reply-To: <e921f92d-52ac-1dc7-7720-c270910c2a2d@kernel.dk>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Precedence: bulk

On 1/16/23 8:44 AM, Jens Axboe wrote:
> On 1/16/23 7:49 AM, Greg Kroah-Hartman wrote:
>> On Mon, Jan 16, 2023 at 07:13:40AM -0700, Jens Axboe wrote:
>>> On 1/16/23 6:42 AM, Jens Axboe wrote:
>>>> On 1/16/23 6:17?AM, Linux kernel regression tracking (Thorsten Leemhuis) wrote:
>>>>> Hi, this is your Linux kernel regression tracker.
>>>>>
>>>>> I noticed a regression report in bugzilla.kernel.org. As many (most?)
>>>>> kernel developer don't keep an eye on it, I decided to forward it by
>>>>> mail. Quoting from https://bugzilla.kernel.org/show_bug.cgi?id=216932 :
>>>>
>>>> Looks like:
>>>>
>>>> commit 6d47e0f6a535701134d950db65eb8fe1edf0b575
>>>> Author: Jens Axboe <axboe@kernel.dk>
>>>> Date:   Wed Jan 4 08:52:06 2023 -0700
>>>>
>>>>     block: don't allow splitting of a REQ_NOWAIT bio
>>>>
>>>> got picked up by stable, but not the required prep patch:
>>>>
>>>>
>>>> commit 613b14884b8595e20b9fac4126bf627313827fbe
>>>> Author: Jens Axboe <axboe@kernel.dk>
>>>> Date:   Wed Jan 4 08:51:19 2023 -0700
>>>>
>>>>     block: handle bio_split_to_limits() NULL return
>>>>
>>>> Greg/team, can you pick the latter too? It'll pick cleanly for
>>>> 6.1-stable, not sure how far back the other patch has gone yet.
>>>
>>> Looked back, and 5.15 has it too, but the cherry-pick won't work
>>> on that kernel.
>>>
>>> Here's one for 5.15-stable that I verified crashes before this one,
>>> and works with it. Haven't done an allmodconfig yet...
>>
>> All now queued up, thanks!
> 
> Thanks Greg! This one was my fault, as it was a set of 2 patches and
> I only marked 2/2 for stable. But how is that best handled? 1/2 could've
> been marked stable as well, but I don't think that would have prevented
> 2/2 applying fine and 1/2 failing and hence not getting queued up until
> I would've done a backport.
> 
> What's the recommended way to describe the dependency that you only
> want 2/2 applied when 1/2 is in as well?

What I'm asking is if we have something like Depends-on or similar
that would explain this dependency. Then patch 2/2 could have:

Depends-on: 613b14884b85 ("block: handle bio_split_to_limits() NULL return")

and then it'd be clear that either both get added, or none of them.

-- 
Jens Axboe