sctp: update the netstamp_needed counter when copying sockets

commit 01ce63c90170283a9855d1db4fe81934dddce648 upstream.

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.

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>

diff --git a/include/net/sock.h b/include/net/sock.h
index 9c24377a7bc9ba00f00e89b9ae7fadf2ae80c35f..d4a6b45f337ff7f0df72e356ece0b035478d2684 100644 (file)
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -702,6 +702,8 @@ 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;

diff --git a/net/core/sock.c b/net/core/sock.c
index 9956e854d0e6e4b39e4529477572b2eb4952f7f3..ac9aa2878d996b3f69a9e1d61a104b65a2996af5 100644 (file)
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -422,8 +422,6 @@ static void sock_warn_obsolete_bsdism(const char *name)
        }
 }
 
-#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) {

diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index a8fd2f57af97f6624d1feea30ea7ee6892c08bcf..e58140abe17e52ceef9e4137371cf800825c85ab 100644 (file)
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -6999,6 +6999,9 @@ void sctp_copy_sock(struct sock *newsk, struct sock *sk,
        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,