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-rw-r--r--net/ipv4/tcp_input.c26
1 files changed, 20 insertions, 6 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 38dfc308c0fb..d95ee40df6c2 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -1302,7 +1302,7 @@ static bool tcp_shifted_skb(struct sock *sk, struct sk_buff *prev,
TCP_SKB_CB(skb)->seq += shifted;
tcp_skb_pcount_add(prev, pcount);
- BUG_ON(tcp_skb_pcount(skb) < pcount);
+ WARN_ON_ONCE(tcp_skb_pcount(skb) < pcount);
tcp_skb_pcount_add(skb, -pcount);
/* When we're adding to gso_segs == 1, gso_size will be zero,
@@ -1368,6 +1368,21 @@ static int skb_can_shift(const struct sk_buff *skb)
return !skb_headlen(skb) && skb_is_nonlinear(skb);
}
+int tcp_skb_shift(struct sk_buff *to, struct sk_buff *from,
+ int pcount, int shiftlen)
+{
+ /* TCP min gso_size is 8 bytes (TCP_MIN_GSO_SIZE)
+ * Since TCP_SKB_CB(skb)->tcp_gso_segs is 16 bits, we need
+ * to make sure not storing more than 65535 * 8 bytes per skb,
+ * even if current MSS is bigger.
+ */
+ if (unlikely(to->len + shiftlen >= 65535 * TCP_MIN_GSO_SIZE))
+ return 0;
+ if (unlikely(tcp_skb_pcount(to) + pcount > 65535))
+ return 0;
+ return skb_shift(to, from, shiftlen);
+}
+
/* Try collapsing SACK blocks spanning across multiple skbs to a single
* skb.
*/
@@ -1473,7 +1488,7 @@ static struct sk_buff *tcp_shift_skb_data(struct sock *sk, struct sk_buff *skb,
if (!after(TCP_SKB_CB(skb)->seq + len, tp->snd_una))
goto fallback;
- if (!skb_shift(prev, skb, len))
+ if (!tcp_skb_shift(prev, skb, pcount, len))
goto fallback;
if (!tcp_shifted_skb(sk, prev, skb, state, pcount, len, mss, dup_sack))
goto out;
@@ -1491,11 +1506,10 @@ static struct sk_buff *tcp_shift_skb_data(struct sock *sk, struct sk_buff *skb,
goto out;
len = skb->len;
- if (skb_shift(prev, skb, len)) {
- pcount += tcp_skb_pcount(skb);
- tcp_shifted_skb(sk, prev, skb, state, tcp_skb_pcount(skb),
+ pcount = tcp_skb_pcount(skb);
+ if (tcp_skb_shift(prev, skb, pcount, len))
+ tcp_shifted_skb(sk, prev, skb, state, pcount,
len, mss, 0);
- }
out:
return prev;