From: Joe Damato <jdamato@fastly.com>
To: Stanislav Fomichev <stfomichev@gmail.com>
Cc: Jakub Kicinski <kuba@kernel.org>,
syzbot <syzbot+846bb38dc67fe62cc733@syzkaller.appspotmail.com>,
davem@davemloft.net, edumazet@google.com, horms@kernel.org,
linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
pabeni@redhat.com, syzkaller-bugs@googlegroups.com
Subject: Re: [syzbot] [net?] possible deadlock in rtnl_newlink
Date: Thu, 29 May 2025 16:54:12 -0700 [thread overview]
Message-ID: <aDjzpDHwcFuGhAqp@LQ3V64L9R2> (raw)
In-Reply-To: <aDiPFiLrhUI0M2MI@mini-arch>
On Thu, May 29, 2025 at 09:45:10AM -0700, Stanislav Fomichev wrote:
> On 05/29, Jakub Kicinski wrote:
> > On Thu, 29 May 2025 08:59:43 -0700 Stanislav Fomichev wrote:
> > > So this is internal WQ entry lock that is being reordered with rtnl
> > > lock. But looking at process_one_work, I don't see actual locks, mostly
> > > lock_map_acquire/lock_map_release calls to enforce some internal WQ
> > > invariants. Not sure what to do with it, will try to read more.
> >
> > Basically a flush_work() happens while holding rtnl_lock,
> > but the work itself takes that lock. It's a driver bug.
>
> e400c7444d84 ("e1000: Hold RTNL when e1000_down can be called") ?
> I think similar things (but wrt netdev instance lock) are happening
> with iavf: iavf_remove calls cancel_work_sync while holding the
> instance lock and the work callbacks grab the instance lock as well :-/
I think this is probably the same thread as:
https://lore.kernel.org/netdev/CAP=Rh=OEsn4y_2LvkO3UtDWurKcGPnZ_NPSXK=FbgygNXL37Sw@mail.gmail.com/
I posted a response there about how to possibly avoid the problem
(based on my rough reading of the driver code), but am still
thinking more on this.
next prev parent reply other threads:[~2025-05-29 23:54 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-05-29 10:32 [syzbot] [net?] possible deadlock in rtnl_newlink syzbot
2025-05-29 15:59 ` Stanislav Fomichev
2025-05-29 16:10 ` Jakub Kicinski
2025-05-29 16:45 ` Stanislav Fomichev
2025-05-29 23:54 ` Joe Damato [this message]
[not found] <20250531011248.2445-1-hdanton@sina.com>
2025-05-31 1:33 ` syzbot
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=aDjzpDHwcFuGhAqp@LQ3V64L9R2 \
--to=jdamato@fastly.com \
--cc=davem@davemloft.net \
--cc=edumazet@google.com \
--cc=horms@kernel.org \
--cc=kuba@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=netdev@vger.kernel.org \
--cc=pabeni@redhat.com \
--cc=stfomichev@gmail.com \
--cc=syzbot+846bb38dc67fe62cc733@syzkaller.appspotmail.com \
--cc=syzkaller-bugs@googlegroups.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).