diff options
| author | Eric Dumazet <edumazet@google.com> | 2013-01-09 20:59:09 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2013-01-10 14:09:57 -0800 |
| commit | f26845b43c75d3f32f98d194c1327b5b1e6b3fb0 (patch) | |
| tree | 8110b37fa3ee70bec5b48db227aa73b55c2e51b8 /net | |
| parent | ff905b1e4aad8ccbbb0d42f7137f19482742ff07 (diff) | |
| download | lwn-f26845b43c75d3f32f98d194c1327b5b1e6b3fb0.tar.gz lwn-f26845b43c75d3f32f98d194c1327b5b1e6b3fb0.zip | |
tcp: fix splice() and tcp collapsing interaction
Under unusual circumstances, TCP collapse can split a big GRO TCP packet
while its being used in a splice(socket->pipe) operation.
skb_splice_bits() releases the socket lock before calling
splice_to_pipe().
[ 1081.353685] WARNING: at net/ipv4/tcp.c:1330 tcp_cleanup_rbuf+0x4d/0xfc()
[ 1081.371956] Hardware name: System x3690 X5 -[7148Z68]-
[ 1081.391820] cleanup rbuf bug: copied AD3BCF1 seq AD370AF rcvnxt AD3CF13
To fix this problem, we must eat skbs in tcp_recv_skb().
Remove the inline keyword from tcp_recv_skb() definition since
it has three call sites.
Reported-by: Christian Becker <c.becker@traviangames.com>
Cc: Willy Tarreau <w@1wt.eu>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Tested-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/ipv4/tcp.c | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 5f173dccd1e9..2aa69c8ae60c 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -1428,12 +1428,12 @@ static void tcp_service_net_dma(struct sock *sk, bool wait) } #endif -static inline struct sk_buff *tcp_recv_skb(struct sock *sk, u32 seq, u32 *off) +static struct sk_buff *tcp_recv_skb(struct sock *sk, u32 seq, u32 *off) { struct sk_buff *skb; u32 offset; - skb_queue_walk(&sk->sk_receive_queue, skb) { + while ((skb = skb_peek(&sk->sk_receive_queue)) != NULL) { offset = seq - TCP_SKB_CB(skb)->seq; if (tcp_hdr(skb)->syn) offset--; @@ -1441,6 +1441,11 @@ static inline struct sk_buff *tcp_recv_skb(struct sock *sk, u32 seq, u32 *off) *off = offset; return skb; } + /* This looks weird, but this can happen if TCP collapsing + * splitted a fat GRO packet, while we released socket lock + * in skb_splice_bits() + */ + sk_eat_skb(sk, skb, false); } return NULL; } @@ -1520,8 +1525,10 @@ int tcp_read_sock(struct sock *sk, read_descriptor_t *desc, tcp_rcv_space_adjust(sk); /* Clean up data we have read: This will do ACK frames. */ - if (copied > 0) + if (copied > 0) { + tcp_recv_skb(sk, seq, &offset); tcp_cleanup_rbuf(sk, copied); + } return copied; } EXPORT_SYMBOL(tcp_read_sock); |