Please ignore the previous version, it had an rbtree artifact which made
it to not apply cleanly, here's the corrected version:
--
[PATCH] [TCP] MTUprobe: fix potential sk_send_head corruption
When the abstraction functions got added, conversion here was
made incorrectly. As a result, the skb may end up pointing
to skb which got included to the probe skb and then was freed.
For it to trigger, however, skb_transmit must fail sending as
well.
Signed-off-by: Ilpo Järvinen <[EMAIL PROTECTED]>
---
include/net/tcp.h | 3 +++
net/ipv4/tcp_output.c | 1 -
2 files changed, 3 insertions(+), 1 deletions(-)
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 1bceca8..f0c5e7a 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -1290,6 +1290,9 @@ static inline void tcp_insert_write_queue_before(struct
sk_buff *new,
struct sock *sk)
{
__skb_insert(new, skb->prev, skb, &sk->sk_write_queue);
+
+ if (sk->sk_send_head == skb)
+ sk->sk_send_head = new;
}
static inline void tcp_unlink_write_queue(struct sk_buff *skb, struct sock *sk)
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index b0ece43..30d6737 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -1346,7 +1346,6 @@ static int tcp_mtu_probe(struct sock *sk)
skb = tcp_send_head(sk);
tcp_insert_write_queue_before(nskb, skb, sk);
- tcp_advance_send_head(sk, skb);
TCP_SKB_CB(nskb)->seq = TCP_SKB_CB(skb)->seq;
TCP_SKB_CB(nskb)->end_seq = TCP_SKB_CB(skb)->seq + probe_size;
--
1.5.0.6
