From: Daniel Borkmann <daniel@iogearbox.net>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>,
"David S. Miller" <davem@davemloft.net>,
Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>,
James Morris <jmorris@namei.org>,
Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>,
Patrick McHardy <kaber@trash.net>,
netdev <netdev@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
Vlad Yasevich <vyasevich@gmail.com>,
Neil Horman <nhorman@tuxdriver.com>,
linux-sctp@vger.kernel.org,
syzkaller <syzkaller@googlegroups.com>,
Kostya Serebryany <kcc@google.com>,
Alexander Potapenko <glider@google.com>,
Sasha Levin <sasha.levin@oracle.com>,
Eric Dumazet <edumazet@google.com>
Subject: Re: memory leak in do_ipv6_setsockopt
Date: Tue, 01 Dec 2015 14:49:07 +0000 [thread overview]
Message-ID: <565DB363.6030702@iogearbox.net> (raw)
In-Reply-To: <1448980723.25582.24.camel@edumazet-glaptop2.roam.corp.google.com>
On 12/01/2015 03:38 PM, Eric Dumazet wrote:
> On Tue, 2015-12-01 at 15:24 +0100, Daniel Borkmann wrote:
>> On 12/01/2015 03:16 PM, Eric Dumazet wrote:
>>> On Tue, 2015-12-01 at 15:07 +0100, Daniel Borkmann wrote:
>>>
>>>> Yeah, we miss inet6_destroy_sock() in SCTP. :-(
>>>>
>>>> Looks good to me.
>>>
>>> OK, I will send a formal (and tested ;) ) patch.
>>
>> I was shortly wondering whether there could be a use-after-free by
>> doing this after sctp_destroy_sock() due to the sctp_endpoint_destroy()
>> that would eventually drop a ref on the socket, but the endpoint holds
>> a separate ref, so we should be good.
>
> More generically ->destroy() caller must keep a reference on the socket.
>
> inet_csk_destroy_sock() for example uses sk after
>
> sk->sk_prot->destroy(sk);
Right, and later on, we might call into ->sk_destruct() when there are no
more refs (in SCTP case: sctp_destruct_sock()).
Thanks,
Daniel
WARNING: multiple messages have this Message-ID (diff)
From: Daniel Borkmann <daniel@iogearbox.net>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>,
"David S. Miller" <davem@davemloft.net>,
Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>,
James Morris <jmorris@namei.org>,
Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>,
Patrick McHardy <kaber@trash.net>,
netdev <netdev@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
Vlad Yasevich <vyasevich@gmail.com>,
Neil Horman <nhorman@tuxdriver.com>,
linux-sctp@vger.kernel.org,
syzkaller <syzkaller@googlegroups.com>,
Kostya Serebryany <kcc@google.com>,
Alexander Potapenko <glider@google.com>,
Sasha Levin <sasha.levin@oracle.com>,
Eric Dumazet <edumazet@google.com>
Subject: Re: memory leak in do_ipv6_setsockopt
Date: Tue, 01 Dec 2015 15:49:07 +0100 [thread overview]
Message-ID: <565DB363.6030702@iogearbox.net> (raw)
In-Reply-To: <1448980723.25582.24.camel@edumazet-glaptop2.roam.corp.google.com>
On 12/01/2015 03:38 PM, Eric Dumazet wrote:
> On Tue, 2015-12-01 at 15:24 +0100, Daniel Borkmann wrote:
>> On 12/01/2015 03:16 PM, Eric Dumazet wrote:
>>> On Tue, 2015-12-01 at 15:07 +0100, Daniel Borkmann wrote:
>>>
>>>> Yeah, we miss inet6_destroy_sock() in SCTP. :-(
>>>>
>>>> Looks good to me.
>>>
>>> OK, I will send a formal (and tested ;) ) patch.
>>
>> I was shortly wondering whether there could be a use-after-free by
>> doing this after sctp_destroy_sock() due to the sctp_endpoint_destroy()
>> that would eventually drop a ref on the socket, but the endpoint holds
>> a separate ref, so we should be good.
>
> More generically ->destroy() caller must keep a reference on the socket.
>
> inet_csk_destroy_sock() for example uses sk after
>
> sk->sk_prot->destroy(sk);
Right, and later on, we might call into ->sk_destruct() when there are no
more refs (in SCTP case: sctp_destruct_sock()).
Thanks,
Daniel
next prev parent reply other threads:[~2015-12-01 14:49 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-12-01 12:27 memory leak in do_ipv6_setsockopt Dmitry Vyukov
2015-12-01 12:27 ` Dmitry Vyukov
2015-12-01 13:36 ` Eric Dumazet
2015-12-01 13:36 ` Eric Dumazet
2015-12-01 14:07 ` Daniel Borkmann
2015-12-01 14:07 ` Daniel Borkmann
2015-12-01 14:16 ` Eric Dumazet
2015-12-01 14:16 ` Eric Dumazet
2015-12-01 14:24 ` Daniel Borkmann
2015-12-01 14:24 ` Daniel Borkmann
2015-12-01 14:38 ` Eric Dumazet
2015-12-01 14:38 ` Eric Dumazet
2015-12-01 14:49 ` Daniel Borkmann [this message]
2015-12-01 14:49 ` Daniel Borkmann
2015-12-01 15:20 ` [PATCH net] ipv6: sctp: implement sctp_v6_destroy_sock() Eric Dumazet
2015-12-01 15:20 ` Eric Dumazet
2015-12-01 15:55 ` Daniel Borkmann
2015-12-01 15:55 ` Daniel Borkmann
2015-12-03 17:06 ` David Miller
2015-12-03 17:06 ` David Miller
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