From: Ming Lei <ming.lei@redhat.com>
To: Luis Chamberlain <mcgrof@kernel.org>
Cc: axboe@kernel.dk, viro@zeniv.linux.org.uk,
gregkh@linuxfoundation.org, rostedt@goodmis.org,
mingo@redhat.com, jack@suse.cz, nstange@suse.de, mhocko@suse.com,
linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org,
linux-kernel@vger.kernel.org, yukuai3@huawei.com
Subject: Re: [RFC 0/3] block: address blktrace use-after-free
Date: Fri, 3 Apr 2020 16:19:29 +0800 [thread overview]
Message-ID: <20200403081929.GC6887@ming.t460p> (raw)
In-Reply-To: <20200402000002.7442-1-mcgrof@kernel.org>
On Wed, Apr 01, 2020 at 11:59:59PM +0000, Luis Chamberlain wrote:
> Upstream kernel.org korg#205713 contends that there is a UAF in
> the core debugfs debugfs_remove() function, and has gone through
> pushing for a CVE for this, CVE-2019-19770.
>
> If correct then parent dentries are not positive, and this would
> have implications far beyond this bug report. Thankfully, upon review
> with Nicolai, he wasn't buying it. His suspicions that this was just
> a blktrace issue were spot on, and this patch series demonstrates
> that, provides a reproducer, and provides a solution to the issue.
>
> We there would like to contend CVE-2019-19770 as invalid. The
> implications suggested are not correct, and this issue is only
> triggerable with root, by shooting yourself on the foot by misuing
> blktrace.
>
> If you want this on a git tree, you can get it from linux-next
> 20200401-blktrace-fix-uaf branch [2].
>
> Wider review, testing, and rants are appreciated.
>
> [0] https://bugzilla.kernel.org/show_bug.cgi?id=205713
> [1] https://nvd.nist.gov/vuln/detail/CVE-2019-19770
> [2] https://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux-next.git/log/?h=20200401-blktrace-fix-uaf
>
> Luis Chamberlain (3):
> block: move main block debugfs initialization to its own file
> blktrace: fix debugfs use after free
> block: avoid deferral of blk_release_queue() work
>
> block/Makefile | 1 +
> block/blk-core.c | 9 +--------
> block/blk-debugfs.c | 27 +++++++++++++++++++++++++++
> block/blk-mq-debugfs.c | 5 -----
> block/blk-sysfs.c | 21 ++++++++-------------
> block/blk.h | 17 +++++++++++++++++
> include/linux/blktrace_api.h | 1 -
> kernel/trace/blktrace.c | 19 ++++++++-----------
> 8 files changed, 62 insertions(+), 38 deletions(-)
> create mode 100644 block/blk-debugfs.c
BTW, Yu Kuai posted one patch for this issue, looks that approach
is simpler:
https://lore.kernel.org/linux-block/20200324132315.22133-1-yukuai3@huawei.com/
Thanks,
Ming
next prev parent reply other threads:[~2020-04-03 8:19 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-01 23:59 [RFC 0/3] block: address blktrace use-after-free Luis Chamberlain
2020-04-02 0:00 ` [RFC 1/3] block: move main block debugfs initialization to its own file Luis Chamberlain
2020-04-05 3:12 ` Bart Van Assche
2020-04-06 14:23 ` Luis Chamberlain
2020-04-02 0:00 ` [RFC 2/3] blktrace: fix debugfs use after free Luis Chamberlain
2020-04-02 1:57 ` Eric Sandeen
2020-04-02 16:14 ` Luis Chamberlain
2020-04-05 3:39 ` Bart Van Assche
2020-04-06 1:27 ` Eric Sandeen
2020-04-06 4:25 ` Bart Van Assche
2020-04-06 9:18 ` Nicolai Stange
2020-04-06 15:19 ` Luis Chamberlain
2020-04-07 8:15 ` Luis Chamberlain
2020-04-06 14:29 ` Eric Sandeen
2020-04-07 8:09 ` Luis Chamberlain
2020-04-06 15:14 ` Luis Chamberlain
2020-04-02 0:00 ` [RFC 3/3] block: avoid deferral of blk_release_queue() work Luis Chamberlain
2020-04-02 3:39 ` Bart Van Assche
2020-04-02 14:49 ` Nicolai Stange
2020-04-06 9:11 ` Nicolai Stange
2020-04-09 18:11 ` Luis Chamberlain
2020-04-02 7:44 ` [RFC 0/3] block: address blktrace use-after-free Greg KH
2020-04-03 8:19 ` Ming Lei [this message]
2020-04-03 14:06 ` Luis Chamberlain
2020-04-03 14:13 ` Bart Van Assche
2020-04-03 19:49 ` Luis Chamberlain
2020-04-07 2:47 ` yukuai (C)
2020-04-07 19:00 ` Luis Chamberlain
2020-04-09 20:59 ` Luis Chamberlain
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200403081929.GC6887@ming.t460p \
--to=ming.lei@redhat.com \
--cc=axboe@kernel.dk \
--cc=gregkh@linuxfoundation.org \
--cc=jack@suse.cz \
--cc=linux-block@vger.kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mcgrof@kernel.org \
--cc=mhocko@suse.com \
--cc=mingo@redhat.com \
--cc=nstange@suse.de \
--cc=rostedt@goodmis.org \
--cc=viro@zeniv.linux.org.uk \
--cc=yukuai3@huawei.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).