Commit f883def5 authored Apr 14, 2022 by Hangbin Liu Committed by Greg Kroah-Hartman Apr 27, 2022

net/packet: fix packet_sock xmit return value checking



[ Upstream commit 29e8e659f984be00d75ec5fef4e37c88def72712 ]

packet_sock xmit could be dev_queue_xmit, which also returns negative
errors. So only checking positive errors is not enough, or userspace
sendmsg may return success while packet is not send out.

Move the net_xmit_errno() assignment in the braces as checkpatch.pl said
do not use assignment in if condition.

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Reported-by: Flavio Leitner <fbl@redhat.com>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>

parent e1bc684c

net/packet/af_packet.c

+9 −4

Original line number	Diff line number	Diff line
		@@ -2791,7 +2791,8 @@ static int tpacket_snd(struct packet_sock po, struct msghdr msg)

		status = TP_STATUS_SEND_REQUEST;
		err = po->xmit(skb);
		if (unlikely(err > 0)) {
		if (unlikely(err != 0)) {
		if (err > 0)
		err = net_xmit_errno(err);
		if (err && __packet_get_status(po, ph) ==
		TP_STATUS_AVAILABLE) {
		@@ -2993,8 +2994,12 @@ static int packet_snd(struct socket sock, struct msghdr msg, size_t len)
		skb->no_fcs = 1;

		err = po->xmit(skb);
		if (err > 0 && (err = net_xmit_errno(err)) != 0)
		if (unlikely(err != 0)) {
		if (err > 0)
		err = net_xmit_errno(err);
		if (err)
		goto out_unlock;
		}

		dev_put(dev);