diff options
| author | Florian Westphal <fw@strlen.de> | 2020-08-14 15:56:34 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2020-08-14 14:11:37 -0700 |
| commit | 35759383133f64d90eba120a0d3efe8f71241650 (patch) | |
| tree | 08b0435c11e611b15290e3afdedbd9182d8b41ed /net | |
| parent | 068885434ccb20542e0d759aebbefe7a6724d85f (diff) | |
mptcp: sendmsg: reset iter on error
Once we've copied data from the iterator we need to revert in case we
end up not sending any data.
This bug doesn't trigger with normal 'poll' based tests, because
we only feed a small chunk of data to kernel after poll indicated
POLLOUT. With blocking IO and large writes this triggers. Receiver
ends up with less data than it should get.
Fixes: 72511aab95c94d ("mptcp: avoid blocking in tcp_sendpages")
Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/mptcp/protocol.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 8c1d1a595701..c84b4051c2a4 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -725,8 +725,10 @@ static int mptcp_sendmsg_frag(struct sock *sk, struct sock *ssk, if (!psize) return -EINVAL; - if (!sk_wmem_schedule(sk, psize + dfrag->overhead)) + if (!sk_wmem_schedule(sk, psize + dfrag->overhead)) { + iov_iter_revert(&msg->msg_iter, psize); return -ENOMEM; + } } else { offset = dfrag->offset; psize = min_t(size_t, dfrag->data_len, avail_size); @@ -737,8 +739,10 @@ static int mptcp_sendmsg_frag(struct sock *sk, struct sock *ssk, */ ret = do_tcp_sendpages(ssk, page, offset, psize, msg->msg_flags | MSG_SENDPAGE_NOTLAST | MSG_DONTWAIT); - if (ret <= 0) + if (ret <= 0) { + iov_iter_revert(&msg->msg_iter, psize); return ret; + } frag_truesize += ret; if (!retransmission) { |