Patch "sctp: update the netstamp_needed counter when copying sockets" has been added to the 4.3-stable tree

This is a note to let you know that I've just added the patch titled

sctp: update the netstamp_needed counter when copying sockets

to the 4.3-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
sctp-update-the-netstamp_needed-counter-when-copying-sockets.patch
and it can be found in the queue-4.3 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Marcelo Ricardo Leitner <[email protected]>
Date: Fri, 4 Dec 2015 15:14:04 -0200
Subject: sctp: update the netstamp_needed counter when copying sockets

From: Marcelo Ricardo Leitner <[email protected]>

[ Upstream commit 01ce63c90170283a9855d1db4fe81934dddce648 ]

Dmitry Vyukov reported that SCTP was triggering a WARN on socket destroy related to disabling sock timestamp.

When SCTP accepts an association or peel one off, it copies sock flags but forgot to call net_enable_timestamp() if a packet timestamping flag was copied, leading to extra calls to net_disable_timestamp() whenever such clones were closed.

The fix is to call net_enable_timestamp() whenever we copy a sock with that flag on, like tcp does.

---
 include/net/sock.h |    2 ++
 net/core/sock.c    |    2 --
 net/sctp/socket.c  |    3 +++
 3 files changed, 5 insertions(+), 2 deletions(-)

@@ -724,6 +724,8 @@ enum sock_flags {
 	SOCK_SELECT_ERR_QUEUE, /* Wake select on error queue */
 };
 
+#define SK_FLAGS_TIMESTAMP ((1UL << SOCK_TIMESTAMP) | (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE))
+
 static inline void sock_copy_flags(struct sock *nsk, struct sock *osk)
 {
 	nsk->sk_flags = osk->sk_flags;

@@ -422,8 +422,6 @@ static void sock_warn_obsolete_bsdism(co
 	}
 }
 
-#define SK_FLAGS_TIMESTAMP ((1UL << SOCK_TIMESTAMP) | (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE))
-
 static void sock_disable_timestamp(struct sock *sk, unsigned long flags)
 {
 	if (sk->sk_flags & flags) {

@@ -7195,6 +7195,9 @@ void sctp_copy_sock(struct sock *newsk,
 	newinet->mc_ttl = 1;
 	newinet->mc_index = 0;
 	newinet->mc_list = NULL;
+
+	if (newsk->sk_flags & SK_FLAGS_TIMESTAMP)
+		net_enable_timestamp();
 }
 
 static inline void sctp_copy_descendant(struct sock *sk_to,

Patches currently in stable-queue which might be from [email protected] are

queue-4.3/sctp-update-the-netstamp_needed-counter-when-copying-sockets.patch queue-4.3/sctp-also-copy-sk_tsflags-when-copying-the-socket.patch queue-4.3/sctp-use-the-same-clock-as-if-sock-source-timestamps-were-on.patch