From: Sasha Levin <sashal@kernel.org>
To: Jan Kara <jack@suse.cz>
Cc: stable-commits@vger.kernel.org, stable@vger.kernel.org
Subject: Re: Patch "fanotify: Release SRCU lock when waiting for userspace response" has been added to the 4.9-stable tree
Date: Fri, 12 Apr 2019 10:43:44 -0400 [thread overview]
Message-ID: <20190412144344.GR11568@sasha-vm> (raw)
In-Reply-To: <20190412084412.GB29850@quack2.suse.cz>
On Fri, Apr 12, 2019 at 10:44:12AM +0200, Jan Kara wrote:
>On Thu 11-04-19 11:26:27, Sasha Levin wrote:
>> This is a note to let you know that I've just added the patch titled
>>
>> fanotify: Release SRCU lock when waiting for userspace response
>>
>> to the 4.9-stable tree which can be found at:
>> http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
>>
>> The filename of the patch is:
>> fanotify-release-srcu-lock-when-waiting-for-userspac.patch
>> and it can be found in the queue-4.9 subdirectory.
>>
>> If you, or anyone else, feels it should not be added to the stable tree,
>> please let <stable@vger.kernel.org> know about it.
>
>I'd be careful with this series. You're missing at least the fixup series
>from Miklos culminating in f37650f1c7c7 "fanotify: fix
>fsnotify_prepare_user_wait() failure". And you seem to be missing also
>quite some prerequisites reworking lifetime of fsnotify marks (series
>culminating with f09b04a03e0 "fsnotify: Remove special handling of mark
>destruction on group shutdown"). So you're just introducing subtle
>use-after-free issues to fanotify code. Overall I think the chances for
>regressions here are much bigger than the problem you'll be fixing unless
>you'll go for something like wholesale update of fs/notify/* to state in
>f37650f1c7c7.
I've pulled this series based on the request here:
https://lore.kernel.org/stable/20190411032430.17353-1-matthew.ruffell@canonical.com/
There are a few reasons why I'd prefer to keep it in:
1. It fixes a very real bug which has affected quite a few of our
customers as well, so (at least for me) this is more than a minor
bugfix.
2. It came with a straightforward testcase.
3. Given that Canonical pulled it in as well, it (hopefully) received
more testing than some other random patches.
If there are missing patches here I'd be happy to take them in and
re-test the kernel, but I'd really like to avoid *not* taking these
patches just because we fear a regression but can't show it.
--
Thanks,
Sasha
next parent reply other threads:[~2019-04-12 14:43 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20190411152628.8E2682173C@mail.kernel.org>
[not found] ` <20190412084412.GB29850@quack2.suse.cz>
2019-04-12 14:43 ` Sasha Levin [this message]
2019-04-15 9:08 ` Patch "fanotify: Release SRCU lock when waiting for userspace response" has been added to the 4.9-stable tree Jan Kara
2019-04-15 10:42 ` Greg KH
2019-04-16 5:11 ` Matthew Ruffell
2019-04-16 9:01 ` Greg KH
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