From f7c51d906832809b390024655eff783ad8a53ad1 Mon Sep 17 00:00:00 2001 From: Hangbin Liu Date: Thu, 14 Apr 2022 16:49:25 +0800 Subject: [PATCH] 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: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: Flavio Leitner Signed-off-by: Hangbin Liu Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/packet/af_packet.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index e79d6881a97e..2ae2801dd7be 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -2808,8 +2808,9 @@ tpacket_error: status = TP_STATUS_SEND_REQUEST; err = po->xmit(skb); - if (unlikely(err > 0)) { - err = net_xmit_errno(err); + if (unlikely(err != 0)) { + if (err > 0) + err = net_xmit_errno(err); if (err && __packet_get_status(po, ph) == TP_STATUS_AVAILABLE) { /* skb was destructed already */ @@ -3009,8 +3010,12 @@ 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) - goto out_unlock; + if (unlikely(err != 0)) { + if (err > 0) + err = net_xmit_errno(err); + if (err) + goto out_unlock; + } dev_put(dev);