sctp: update the netstamp_needed counter when copying sockets

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>

diff --git a/include/net/sock.h b/include/net/sock.h
index 52d27ee..b1d475b 100644 (file)
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -740,6 +740,8 @@ 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 e31dfce..d01c8f4 100644 (file)
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -433,8 +433,6 @@ static bool sock_needs_netstamp(const struct sock *sk)
        }
 }
 
-#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 03c8256..4c9282b 100644 (file)
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -7199,6 +7199,9 @@ 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,