diff options
| author | Eric Dumazet <edumazet@google.com> | 2019-08-06 17:09:14 +0200 |
|---|---|---|
| committer | Jason Liu <jason.hui.liu@nxp.com> | 2019-09-06 15:49:42 +0800 |
| commit | a5982ca5602bdc57db4214971b55e01e6d2ea353 (patch) | |
| tree | e24d41b80bc11f164dd3db9a1a924a3d87a98c71 /include | |
| parent | b69ce5a2cfca586f9c3e7d784bfc2ba402a0515b (diff) | |
tcp: be more careful in tcp_fragment()
commit b617158dc096709d8600c53b6052144d12b89fab upstream.
Some applications set tiny SO_SNDBUF values and expect
TCP to just work. Recent patches to address CVE-2019-11478
broke them in case of losses, since retransmits might
be prevented.
We should allow these flows to make progress.
This patch allows the first and last skb in retransmit queue
to be split even if memory limits are hit.
It also adds the some room due to the fact that tcp_sendmsg()
and tcp_sendpage() might overshoot sk_wmem_queued by about one full
TSO skb (64KB size). Note this allowance was already present
in stable backports for kernels < 4.15
Note for < 4.15 backports :
tcp_rtx_queue_tail() will probably look like :
static inline struct sk_buff *tcp_rtx_queue_tail(const struct sock *sk)
{
struct sk_buff *skb = tcp_send_head(sk);
return skb ? tcp_write_queue_prev(sk, skb) : tcp_write_queue_tail(sk);
}
Fixes: f070ef2ac667 ("tcp: tcp_fragment() should apply sane memory limits")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Andrew Prout <aprout@ll.mit.edu>
Tested-by: Andrew Prout <aprout@ll.mit.edu>
Tested-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Tested-by: Michal Kubecek <mkubecek@suse.cz>
Acked-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Christoph Paasch <cpaasch@apple.com>
Cc: Jonathan Looney <jtl@netflix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
(cherry picked from commit 8c3088f895a0cfdf630973a9cd32f5e085eb973c)
Diffstat (limited to 'include')
| -rw-r--r-- | include/net/tcp.h | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/include/net/tcp.h b/include/net/tcp.h index 0b477a1e1177..7994e569644e 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -1688,6 +1688,23 @@ static inline void tcp_check_send_head(struct sock *sk, struct sk_buff *skb_unli tcp_sk(sk)->highest_sack = NULL; } +static inline struct sk_buff *tcp_rtx_queue_head(const struct sock *sk) +{ + struct sk_buff *skb = tcp_write_queue_head(sk); + + if (skb == tcp_send_head(sk)) + skb = NULL; + + return skb; +} + +static inline struct sk_buff *tcp_rtx_queue_tail(const struct sock *sk) +{ + struct sk_buff *skb = tcp_send_head(sk); + + return skb ? tcp_write_queue_prev(sk, skb) : tcp_write_queue_tail(sk); +} + static inline void __tcp_add_write_queue_tail(struct sock *sk, struct sk_buff *skb) { __skb_queue_tail(&sk->sk_write_queue, skb); |