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authorEric Dumazet2012-12-01 13:07:02 +0000
committerDavid S. Miller2012-12-01 20:39:16 -0500
commit64022d0b4e93ea432e95db55a72b8a1c5775f3c0 (patch)
treeea2ac7d7a7ed903d645c21d99f02ff6fdbb6aa96
parent9f8933e960f98d27742727445061b0ece934e5cf (diff)
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>
-rw-r--r--net/ipv4/tcp.c15
1 files changed, 6 insertions, 9 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 083092e3aed6..e457c7ab2e28 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -830,8 +830,8 @@ static int tcp_send_mss(struct sock *sk, int *size_goal, int flags)
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 @@ static ssize_t do_tcp_sendpages(struct sock *sk, struct page **pages, int poffse
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 @@ new_segment:
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 @@ int tcp_sendpage(struct sock *sk, struct page *page, int offset,
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;
}