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mptcp: sendmsg: reset iter on error redux

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This fix wasn't correct: When this function is invoked from the
retransmission worker, the iterator contains garbage and resetting
it causes a crash.

As the work queue should not be performance critical also zero the
msghdr struct.

Fixes: 3575938313 "(mptcp: sendmsg: reset iter on error)"
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Florian Westphal 2020-08-16 23:14:20 +02:00 committed by David S. Miller
parent bd71ea6067
commit b3b2854dcf
1 changed files with 5 additions and 3 deletions
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8
net/mptcp/protocol.c
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@ -740,7 +740,8 @@ 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) {
iov_iter_revert(&msg->msg_iter, psize);
if (!retransmission)
iov_iter_revert(&msg->msg_iter, psize);
return ret;
}
@ -1392,7 +1393,9 @@ static void mptcp_worker(struct work_struct *work)
struct mptcp_data_frag *dfrag;
u64 orig_write_seq;
size_t copied = 0;
struct msghdr msg;
struct msghdr msg = {
.msg_flags = MSG_DONTWAIT,
};
long timeo = 0;
lock_sock(sk);
@ -1425,7 +1428,6 @@ static void mptcp_worker(struct work_struct *work)
lock_sock(ssk);
msg.msg_flags = MSG_DONTWAIT;
orig_len = dfrag->data_len;
orig_offset = dfrag->offset;
orig_write_seq = dfrag->data_seq;