Messages in this thread Patch in this message | | | From | Nixiaoming <> | Subject | Re:Re: [PATCH] net/packet: fix race condition between fanout_add and __unregister_prot_hook | Date | Tue, 19 Sep 2017 07:50:55 +0000 |
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On Fri, Sep 15, 2017 at 10:46 AM, Willem de Bruijn <willemdebruijn.kernel@gmail.com> wrote: > > In case of failure we also need to unlink and free match. I > sent the following: > > http://patchwork.ozlabs.org/patch/813945/
+ spin_lock(&po->bind_lock); + if (po->running && + match->type == type && match->prot_hook.type == po->prot_hook.type && match->prot_hook.dev == po->prot_hook.dev) { err = -ENOSPC; @@ -1761,6 +1760,13 @@ static int fanout_add(struct sock *sk, u16 id, u16 type_flags) err = 0; } } + spin_unlock(&po->bind_lock); + + if (err && !refcount_read(&match->sk_ref)) { + list_del(&match->list); + kfree(match); + }
In the function fanout_add add spin_lock to protect po-> running and po-> fanout, then whether it should be in the function fanout_release also add spin_lock protection ?
static struct packet_fanout *fanout_release(struct sock *sk) .... mutex_lock(&fanout_mutex); f = po->fanout; if (f) { po->fanout = NULL;
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