From: asmadeus@codewreck•org
To: Vlastimil Babka <vbabka@suse•cz>
Cc: syzbot <syzbot+5e28cdb7ebd0f2389ca4@syzkaller•appspotmail.com>,
akpm@linux-foundation•org, davem@davemloft•net,
edumazet@google•com, elver@google•com, ericvh@gmail•com,
hdanton@sina•com, k.kahurani@gmail•com, kuba@kernel•org,
linux-kernel@vger•kernel.org, linux_oss@crudebyte•com,
lucho@ionkov•net, netdev@vger•kernel.org, pabeni@redhat•com,
rientjes@google•com, syzkaller-bugs@googlegroups•com,
torvalds@linux-foundation•org,
v9fs-developer@lists•sourceforge.net
Subject: Re: [syzbot] WARNING in p9_client_destroy
Date: Mon, 25 Jul 2022 20:50:38 +0900 [thread overview]
Message-ID: <Yt6DjrMdIhpQmm7V@codewreck.org> (raw)
In-Reply-To: <fb9febe5-00a6-61e9-a2d0-40982f9721a3@suse.cz>
Vlastimil Babka wrote on Mon, Jul 25, 2022 at 12:15:24PM +0200:
> On 7/24/22 15:17, syzbot wrote:
> > syzbot has bisected this issue to:
> >
> > commit 7302e91f39a81a9c2efcf4bc5749d18128366945
> > Author: Marco Elver <elver@google•com>
> > Date: Fri Jan 14 22:03:58 2022 +0000
> >
> > mm/slab_common: use WARN() if cache still has objects on destroy
>
> Just to state the obvious, bisection pointed to a commit that added the
> warning, but the reason for the warning would be that p9 is destroying a
> kmem_cache without freeing all the objects there first, and that would be
> true even before the commit.
Probably true from the moment that cache/idr was introduced... I've got
a couple of fixes in next but given syzcaller claims that's the tree it
was produced on I guess there can be more such leaks.
(well, the lines it sent in the backtrace yesterday don't match next,
but I wouldn't count on it)
If someone wants to have a look please feel free, I would bet the
problem is just that p9_fd_close() doesn't call or does something
equivalent to p9_conn_cancel() and there just are some requests that
haven't been sent yet when the mount is closed..
But I don't have/can/want to take the time to check right now as I
consider such a leak harmless enough, someone has to be root or
equivalent to do 9p mounts in most cases.
--
Dominique
next prev parent reply other threads:[~2022-07-25 11:51 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
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 [this message]
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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