All of lore.kernel.org
 help / color / mirror / Atom feed
From: Johannes Berg <johannes@sipsolutions.net>
To: syzbot <syzbot+9817a610349542589c42@syzkaller.appspotmail.com>,
	davem@davemloft.net, edumazet@google.com, kuba@kernel.org,
	linux-kernel@vger.kernel.org, linux-wireless@vger.kernel.org,
	netdev@vger.kernel.org, pabeni@redhat.com,
	syzkaller-bugs@googlegroups.com
Subject: Re: [syzbot] [wireless?] WARNING in ieee80211_link_release_channel
Date: Mon, 04 Sep 2023 08:57:11 +0200	[thread overview]
Message-ID: <cf6ab60c42705625a7b1d71e53db0edb78fe6e2d.camel@sipsolutions.net> (raw)
In-Reply-To: <000000000000bcd80b06046a98ac@google.com>

On Sat, 2023-09-02 at 18:48 -0700, syzbot wrote:
> 
> WARNING: CPU: 0 PID: 7597 at net/mac80211/chan.c:2021 ieee80211_link_release_channel+0x19f/0x200 net/mac80211/chan.c:2021
> 

That's a lockdep warning, so it's kind of a known issue. I don't know if
I've yet encountered this specific way to get the locking checks
screaming, but generally we knew for a while that the locking was a bit
messy and possibly to some extent broken (*).

Anyway, point is - this is basically the reason I did this series:
https://lore.kernel.org/linux-wireless/20230828115927.116700-41-johannes@sipsolutions.net/

so this should go away - though sadly only in -next. Per the footnote, I
believe that the issue in the current kernel is mostly not an issue, and
it should only happen with multi-link in the first place. There may be
an issue in what syzbot found, processing a multi-link response or
something though.

johannes

(*) in many cases it's not _actually_ broken because we hold some common
outer lock anyway, so no data races are possible

  reply	other threads:[~2023-09-04  6:57 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-09-03  1:48 [syzbot] [wireless?] WARNING in ieee80211_link_release_channel syzbot
2023-09-04  6:57 ` Johannes Berg [this message]
2023-11-07  8:25 ` syzbot
2023-12-03 17:12 ` 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=cf6ab60c42705625a7b1d71e53db0edb78fe6e2d.camel@sipsolutions.net \
    --to=johannes@sipsolutions.net \
    --cc=davem@davemloft.net \
    --cc=edumazet@google.com \
    --cc=kuba@kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-wireless@vger.kernel.org \
    --cc=netdev@vger.kernel.org \
    --cc=pabeni@redhat.com \
    --cc=syzbot+9817a610349542589c42@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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.