net: really orphan skbs tied to closing sk

If the owing socket is shutting down - e.g. the sock reference
count already dropped to 0 and only sk_wmem_alloc is keeping
the sock alive, skb_orphan_partial() becomes a no-op.

When forwarding packets over veth with GRO enabled, the above
causes refcount errors.

This change addresses the issue with a plain skb_orphan() call
in the critical scenario.

Fixes: 9adc89af72 ("net: let skb_orphan_partial wake-up waiters.")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Paolo Abeni 2021-05-11 10:35:21 +02:00 committed by David S. Miller
parent 440c3247cb
commit 098116e7e6
2 changed files with 7 additions and 5 deletions

View File

@ -2231,13 +2231,15 @@ static inline void skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
sk_mem_charge(sk, skb->truesize);
}
static inline void skb_set_owner_sk_safe(struct sk_buff *skb, struct sock *sk)
static inline __must_check bool skb_set_owner_sk_safe(struct sk_buff *skb, struct sock *sk)
{
if (sk && refcount_inc_not_zero(&sk->sk_refcnt)) {
skb_orphan(skb);
skb->destructor = sock_efree;
skb->sk = sk;
return true;
}
return false;
}
void sk_reset_timer(struct sock *sk, struct timer_list *timer,

View File

@ -2132,10 +2132,10 @@ void skb_orphan_partial(struct sk_buff *skb)
if (skb_is_tcp_pure_ack(skb))
return;
if (can_skb_orphan_partial(skb))
skb_set_owner_sk_safe(skb, skb->sk);
else
skb_orphan(skb);
if (can_skb_orphan_partial(skb) && skb_set_owner_sk_safe(skb, skb->sk))
return;
skb_orphan(skb);
}
EXPORT_SYMBOL(skb_orphan_partial);