diff options
| author | Eric Dumazet <edumazet@google.com> | 2017-05-11 15:24:41 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-06-07 12:05:59 +0200 |
| commit | 605b6b2b4d8a8abdafb675abda2e43c11d1b3921 (patch) | |
| tree | 57cb55fbbf7486c6526a81ea118f3d35812d584c /net/core | |
| parent | 338f665acb4ba0b2c7656cc2487326497220168f (diff) | |
netem: fix skb_orphan_partial()
commit f6ba8d33cfbb46df569972e64dbb5bb7e929bfd9 upstream.
I should have known that lowering skb->truesize was dangerous :/
In case packets are not leaving the host via a standard Ethernet device,
but looped back to local sockets, bad things can happen, as reported
by Michael Madsen ( https://bugzilla.kernel.org/show_bug.cgi?id=195713 )
So instead of tweaking skb->truesize, lets change skb->destructor
and keep a reference on the owner socket via its sk_refcnt.
Fixes: f2f872f9272a ("netem: Introduce skb_orphan_partial() helper")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Michael Madsen <mkm@nabto.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net/core')
| -rw-r--r-- | net/core/sock.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/net/core/sock.c b/net/core/sock.c index 9c708a5fb751..bd2fad27891e 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -1690,17 +1690,17 @@ EXPORT_SYMBOL(skb_set_owner_w); void skb_orphan_partial(struct sk_buff *skb) { - /* TCP stack sets skb->ooo_okay based on sk_wmem_alloc, - * so we do not completely orphan skb, but transfert all - * accounted bytes but one, to avoid unexpected reorders. - */ if (skb->destructor == sock_wfree #ifdef CONFIG_INET || skb->destructor == tcp_wfree #endif ) { - atomic_sub(skb->truesize - 1, &skb->sk->sk_wmem_alloc); - skb->truesize = 1; + struct sock *sk = skb->sk; + + if (atomic_inc_not_zero(&sk->sk_refcnt)) { + atomic_sub(skb->truesize, &sk->sk_wmem_alloc); + skb->destructor = sock_efree; + } } else { skb_orphan(skb); } |