From: asmadeus@codewreck.org
To: syzbot <syzbot+5e28cdb7ebd0f2389ca4@syzkaller.appspotmail.com>
Cc: davem@davemloft.net, ericvh@gmail.com, kuba@kernel.org,
linux-kernel@vger.kernel.org, linux_oss@crudebyte.com,
lucho@ionkov.net, netdev@vger.kernel.org,
syzkaller-bugs@googlegroups.com,
v9fs-developer@lists.sourceforge.net
Subject: Re: [syzbot] WARNING in p9_client_destroy
Date: Mon, 28 Feb 2022 10:38:33 +0900 [thread overview]
Message-ID: <YhwnmR5hbseg0EJd@codewreck.org> (raw)
In-Reply-To: <00000000000011f0c905d9097a62@google.com>
syzbot wrote on Sun, Feb 27, 2022 at 04:53:29PM -0800:
> kmem_cache_destroy 9p-fcall-cache: Slab cache still has objects when
> called from p9_client_destroy+0x213/0x370 net/9p/client.c:1100
hmm, there is no previous "Packet with tag %d has still references"
(sic) message, so this is probably because p9_tag_cleanup only relies on
rcu read lock for consistency, so even if the connection has been closed
above (clnt->trans_mode->close) there could have been a request sent
(= tag added) just before that which isn't visible on the destroying
side?
I guess adding an rcu_barrier() is what makes most sense here to protect
this case?
I'll send a patch in the next few days unless it was a stupid idea.
--
Dominique
next prev parent reply other threads:[~2022-02-28 1:39 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-28 0:53 [syzbot] WARNING in p9_client_destroy syzbot
2022-02-28 1:38 ` asmadeus [this message]
2022-07-24 8:28 ` syzbot
2022-07-24 13:17 ` syzbot
2022-07-25 10:15 ` Vlastimil Babka
2022-07-25 11:50 ` asmadeus
2022-07-25 12:45 ` Dmitry Vyukov
2022-07-26 12:09 ` Christian Schoenebeck
2022-07-29 12:31 ` Dmitry Vyukov
[not found] <CAAZOf26g-L2nSV-Siw6mwWQv1nv6on8c0fWqB4bKmX73QAFzow@mail.gmail.com>
2022-03-26 11:46 ` David Kahurani
2022-03-26 11:48 ` Christian Schoenebeck
2022-03-26 12:24 ` asmadeus
2022-03-26 12:36 ` Christian Schoenebeck
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