From 1f1b431a4fcd96a6be85ab5a61bd874960d182cf Mon Sep 17 00:00:00 2001 From: Paolo Abeni Date: Tue, 11 May 2021 10:35:21 +0200 Subject: [PATCH] net: really orphan skbs tied to closing sk [ Upstream commit 098116e7e640ba677d9e345cbee83d253c13d556 ] 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: 9adc89af724f ("net: let skb_orphan_partial wake-up waiters.") Signed-off-by: Paolo Abeni Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- include/net/sock.h | 4 +++- net/core/sock.c | 8 ++++---- 2 files changed, 7 insertions(+), 5 deletions(-) diff --git a/include/net/sock.h b/include/net/sock.h index 2611955..f68184b 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -2197,13 +2197,15 @@ 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, diff --git a/net/core/sock.c b/net/core/sock.c index c75c1e7..dee29f4 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -2099,10 +2099,10 @@ 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); -- 2.7.4