tcp: fix crashes in do_tcp_sendpages()
Recent network changes allowed high order pages being used
for skb fragments.
This uncovered a bug in do_tcp_sendpages() which was assuming its caller
provided an array of order-0 page pointers.
We only have to deal with a single page in this function, and its order
is irrelevant.
Reported-by: Willy Tarreau <w@1wt.eu>
Tested-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 083092e..e457c7a 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -830,8 +830,8 @@
return mss_now;
}
-static ssize_t do_tcp_sendpages(struct sock *sk, struct page **pages, int poffset,
- size_t psize, int flags)
+static ssize_t do_tcp_sendpages(struct sock *sk, struct page *page, int offset,
+ size_t size, int flags)
{
struct tcp_sock *tp = tcp_sk(sk);
int mss_now, size_goal;
@@ -858,12 +858,9 @@
if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
goto out_err;
- while (psize > 0) {
+ while (size > 0) {
struct sk_buff *skb = tcp_write_queue_tail(sk);
- struct page *page = pages[poffset / PAGE_SIZE];
int copy, i;
- int offset = poffset % PAGE_SIZE;
- int size = min_t(size_t, psize, PAGE_SIZE - offset);
bool can_coalesce;
if (!tcp_send_head(sk) || (copy = size_goal - skb->len) <= 0) {
@@ -912,8 +909,8 @@
TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_PSH;
copied += copy;
- poffset += copy;
- if (!(psize -= copy))
+ offset += copy;
+ if (!(size -= copy))
goto out;
if (skb->len < size_goal || (flags & MSG_OOB))
@@ -960,7 +957,7 @@
flags);
lock_sock(sk);
- res = do_tcp_sendpages(sk, &page, offset, size, flags);
+ res = do_tcp_sendpages(sk, page, offset, size, flags);
release_sock(sk);
return res;
}