netdev - [PATCH v3] net: tcp: fix rx timestamp behavior for tcp

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20200508142309.11292-1-kelly@onechronos.com>
Date:   Fri,  8 May 2020 14:23:10 +0000
From:   Kelly Littlepage <kelly@...chronos.com>
To:     willemdebruijn.kernel@...il.com
Cc:     davem@...emloft.net, edumazet@...gle.com, iris@...chronos.com,
        kelly@...chronos.com, kuba@...nel.org, kuznet@....inr.ac.ru,
        maloney@...gle.com, netdev@...r.kernel.org, soheil@...gle.com,
        yoshfuji@...ux-ipv6.org
Subject: [PATCH v3] net: tcp: fix rx timestamp behavior for tcp_recvmsg

The stated intent of the original commit is to is to "return the timestamp
corresponding to the highest sequence number data returned." The current
implementation returns the timestamp for the last byte of the last fully
read skb, which is not necessarily the last byte in the recv buffer. This
patch converts behavior to the original definition, and to the behavior of
the previous draft versions of commit 98aaa913b4ed ("tcp: Extend
SOF_TIMESTAMPING_RX_SOFTWARE to TCP recvmsg") which also match this
behavior.

Fixes: 98aaa913b4ed ("tcp: Extend SOF_TIMESTAMPING_RX_SOFTWARE to TCP recvmsg")
Co-developed-by: Iris Liu <iris@...chronos.com>
Signed-off-by: Iris Liu <iris@...chronos.com>
Signed-off-by: Kelly Littlepage <kelly@...chronos.com>
---
Reverted to the original subject line

 net/ipv4/tcp.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 6d87de434377..e72bd651d21a 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2154,13 +2154,15 @@ int tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int nonblock,
 			tp->urg_data = 0;
 			tcp_fast_path_check(sk);
 		}
-		if (used + offset < skb->len)
-			continue;
 
 		if (TCP_SKB_CB(skb)->has_rxtstamp) {
 			tcp_update_recv_tstamps(skb, &tss);
 			cmsg_flags |= 2;
 		}
+
+		if (used + offset < skb->len)
+			continue;
+
 		if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)
 			goto found_fin_ok;
 		if (!(flags & MSG_PEEK))
-- 
2.26.2


-- 
This email and any attachments thereto may contain private, confidential, 
and privileged material for the sole use of the intended recipient. If you 
are not the intended recipient or otherwise believe that you have received 
this message in error, please notify the sender immediately and delete the 
original. Any review, copying, or distribution of this email (or any 
attachments thereto) by others is strictly prohibited. If this message was 
misdirected, OCX Group Inc. does not waive any confidentiality or privilege.