From: stranche@codeaurora•org
To: Eric Dumazet <eric.dumazet@gmail•com>
Cc: netdev@vger•kernel.org, steffen.klassert@secunet•com
Subject: Re: [PATCH net] af_key: free SKBs under RCU protection
Date: Mon, 24 Sep 2018 12:46:07 -0600 [thread overview]
Message-ID: <c30e965c4290b3a4a7ec8f91fa587598@codeaurora.org> (raw)
In-Reply-To: <9a3d8036-9f8c-6e8b-f16c-7c278c448db3@gmail.com>
On 2018-09-23 11:15, Eric Dumazet wrote:
> On 09/20/2018 12:25 PM, stranche@codeaurora•org wrote:
>
>> Perhaps a cleaner solution here is to always clone the SKB in
>> pfkey_broadcast_one(). That will ensure that the two kfree_skb() calls
>> in pfkey_broadcast() will never be passed an SKB with sock_rfree() as
>> its destructor, and we can avoid this race condition.
>
> Yes, this whole idea of avoiding the cloning is brain dead.
>
> Better play safe and having a straightforward implementation.
>
> I suggest something like this (I could not reproduce the bug with the
> syzkaller repro)
>
> Note that I removed the sock_hold(sk)/sock_put(sk) pair as this is
> useless.
> The only time GFP_KERNEL might be used is when the sk is already owned
> by the caller.
>
>
> net/key/af_key.c | 40 +++++++++++++++-------------------------
> 1 file changed, 15 insertions(+), 25 deletions(-)
Hi Eric,
That patch works like a charm. Could you upload that as a formal patch?
Thanks for all your help with this.
prev parent reply other threads:[~2018-09-25 0:49 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-20 0:18 [PATCH net] af_key: free SKBs under RCU protection Sean Tranchetti
2018-09-20 13:29 ` Eric Dumazet
2018-09-20 19:25 ` stranche
2018-09-20 22:10 ` Eric Dumazet
2018-09-20 22:29 ` Eric Dumazet
2018-09-21 17:09 ` stranche
2018-09-21 17:40 ` Eric Dumazet
2018-09-21 18:44 ` stranche
2018-09-23 17:15 ` Eric Dumazet
2018-09-24 18:46 ` stranche [this message]
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