From: David Miller <davem@redhat.com>
To: eric.dumazet@gmail.com
Cc: mleitner@redhat.com, edumazet@google.com, netdev@vger.kernel.org,
ycheng@google.com, mattmathis@google.com, cgallek@google.com,
kafai@fb.com
Subject: Re: [PATCH net-next] tcp: fix a potential deadlock in tcp_get_info()
Date: Fri, 22 May 2015 13:50:42 -0400 (EDT) [thread overview]
Message-ID: <20150522.135042.1383929510137041615.davem@redhat.com> (raw)
In-Reply-To: <1432270279.4060.128.camel@edumazet-glaptop2.roam.corp.google.com>
From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Thu, 21 May 2015 21:51:19 -0700
> From: Eric Dumazet <edumazet@google.com>
>
> Taking socket spinlock in tcp_get_info() can deadlock, as
> inet_diag_dump_icsk() holds the &hashinfo->ehash_locks[i],
> while packet processing can use the reverse locking order.
>
> We could avoid this locking for TCP_LISTEN states, but lockdep would
> certainly get confused as all TCP sockets share same lockdep classes.
...
> Lets use u64_sync infrastructure instead. As a bonus, 64bit
> arches get optimized, as these are nop for them.
>
> Fixes: 0df48c26d841 ("tcp: add tcpi_bytes_acked to tcp_info")
> Signed-off-by: Eric Dumazet <edumazet@google.com>
This bug exists in 'net' so I've applied it there.
Thanks Eric.
next prev parent reply other threads:[~2015-05-22 17:50 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-04-28 22:28 [PATCH v2 net-next 0/2] tcp: tcp_info extensions Eric Dumazet
2015-04-28 22:28 ` [PATCH v2 net-next 1/2] tcp: add tcpi_bytes_acked to tcp_info Eric Dumazet
2015-04-29 22:12 ` David Miller
2015-04-28 22:28 ` [PATCH v2 net-next 2/2] tcp: add tcpi_bytes_received " Eric Dumazet
2015-04-28 22:56 ` Yuchung Cheng
2015-04-28 23:07 ` Eric Dumazet
2015-04-29 22:12 ` David Miller
2015-05-12 13:08 ` [PATCH v2 net-next 0/2] tcp: tcp_info extensions Marcelo Ricardo Leitner
2015-05-12 20:31 ` Eric Dumazet
2015-05-12 22:21 ` Marcelo Ricardo Leitner
2015-05-20 23:35 ` [PATCH net-next] tcp: add tcpi_segs_in and tcpi_segs_out to tcp_info Eric Dumazet
2015-05-21 0:06 ` Rick Jones
2015-05-21 0:37 ` Eric Dumazet
2015-05-21 0:48 ` Rick Jones
2015-05-21 0:52 ` Eric Dumazet
2015-05-21 12:38 ` Marcelo Ricardo Leitner
2015-05-21 19:41 ` Yuchung Cheng
2015-05-21 20:06 ` Eric Dumazet
2015-05-21 21:53 ` Marcelo Ricardo Leitner
2015-05-22 3:25 ` David Miller
2015-05-22 3:43 ` Eric Dumazet
2015-05-22 4:51 ` [PATCH net-next] tcp: fix a potential deadlock in tcp_get_info() Eric Dumazet
2015-05-22 17:50 ` David Miller [this message]
2015-05-22 17:56 ` Eric Dumazet
2015-05-22 18:03 ` Eric Dumazet
2015-05-22 18:08 ` Eric Dumazet
2015-05-22 18:21 ` David Miller
2015-05-22 18:12 ` David Miller
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