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-rw-r--r--include/linux/skbuff.h10
-rw-r--r--net/ipv4/tcp_output.c9
2 files changed, 16 insertions, 3 deletions
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index dc4d49a0c07d..daabf24655af 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -760,6 +760,16 @@ static inline int skb_cloned(const struct sk_buff *skb)
(atomic_read(&skb_shinfo(skb)->dataref) & SKB_DATAREF_MASK) != 1;
}
+static inline int skb_unclone(struct sk_buff *skb, gfp_t pri)
+{
+ might_sleep_if(pri & __GFP_WAIT);
+
+ if (skb_cloned(skb))
+ return pskb_expand_head(skb, 0, 0, pri);
+
+ return 0;
+}
+
/**
* skb_header_cloned - is the header a clone
* @skb: buffer to check
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 12999a3aaf95..987f5cc706b4 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -933,6 +933,9 @@ static void tcp_queue_skb(struct sock *sk, struct sk_buff *skb)
static void tcp_set_skb_tso_segs(const struct sock *sk, struct sk_buff *skb,
unsigned int mss_now)
{
+ /* Make sure we own this skb before messing gso_size/gso_segs */
+ WARN_ON_ONCE(skb_cloned(skb));
+
if (skb->len <= mss_now || !sk_can_gso(sk) ||
skb->ip_summed == CHECKSUM_NONE) {
/* Avoid the costly divide in the normal
@@ -1014,9 +1017,7 @@ int tcp_fragment(struct sock *sk, struct sk_buff *skb, u32 len,
if (nsize < 0)
nsize = 0;
- if (skb_cloned(skb) &&
- skb_is_nonlinear(skb) &&
- pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
+ if (skb_unclone(skb, GFP_ATOMIC))
return -ENOMEM;
/* Get a new skb... force flag on. */
@@ -2129,6 +2130,8 @@ int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb)
int oldpcount = tcp_skb_pcount(skb);
if (unlikely(oldpcount > 1)) {
+ if (skb_unclone(skb, GFP_ATOMIC))
+ return -ENOMEM;
tcp_init_tso_segs(sk, skb, cur_mss);
tcp_adjust_pcount(sk, skb, oldpcount - tcp_skb_pcount(skb));
}