Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next

Pull networking updates from David Miller:

 1) New ipset extensions for matching on destination MAC addresses, from
    Stefano Brivio.

 2) Add ipv4 ttl and tos, plus ipv6 flow label and hop limit offloads to
    nfp driver. From Stefano Brivio.

 3) Implement GRO for plain UDP sockets, from Paolo Abeni.

 4) Lots of work from Michał Mirosław to eliminate the VLAN_TAG_PRESENT
    bit so that we could support the entire vlan_tci value.

 5) Rework the IPSEC policy lookups to better optimize more usecases,
    from Florian Westphal.

 6) Infrastructure changes eliminating direct manipulation of SKB lists
    wherever possible, and to always use the appropriate SKB list
    helpers. This work is still ongoing...

 7) Lots of PHY driver and state machine improvements and
    simplifications, from Heiner Kallweit.

 8) Various TSO deferral refinements, from Eric Dumazet.

 9) Add ntuple filter support to aquantia driver, from Dmitry Bogdanov.

10) Batch dropping of XDP packets in tuntap, from Jason Wang.

11) Lots of cleanups and improvements to the r8169 driver from Heiner
    Kallweit, including support for ->xmit_more. This driver has been
    getting some much needed love since he started working on it.

12) Lots of new forwarding selftests from Petr Machata.

13) Enable VXLAN learning in mlxsw driver, from Ido Schimmel.

14) Packed ring support for virtio, from Tiwei Bie.

15) Add new Aquantia AQtion USB driver, from Dmitry Bezrukov.

16) Add XDP support to dpaa2-eth driver, from Ioana Ciocoi Radulescu.

17) Implement coalescing on TCP backlog queue, from Eric Dumazet.

18) Implement carrier change in tun driver, from Nicolas Dichtel.

19) Support msg_zerocopy in UDP, from Willem de Bruijn.

20) Significantly improve garbage collection of neighbor objects when
    the table has many PERMANENT entries, from David Ahern.

21) Remove egdev usage from nfp and mlx5, and remove the facility
    completely from the tree as it no longer has any users. From Oz
    Shlomo and others.

22) Add a NETDEV_PRE_CHANGEADDR so that drivers can veto the change and
    therefore abort the operation before the commit phase (which is the
    NETDEV_CHANGEADDR event). From Petr Machata.

23) Add indirect call wrappers to avoid retpoline overhead, and use them
    in the GRO code paths. From Paolo Abeni.

24) Add support for netlink FDB get operations, from Roopa Prabhu.

25) Support bloom filter in mlxsw driver, from Nir Dotan.

26) Add SKB extension infrastructure. This consolidates the handling of
    the auxiliary SKB data used by IPSEC and bridge netfilter, and is
    designed to support the needs to MPTCP which could be integrated in
    the future.

27) Lots of XDP TX optimizations in mlx5 from Tariq Toukan.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1845 commits)
  net: dccp: fix kernel crash on module load
  drivers/net: appletalk/cops: remove redundant if statement and mask
  bnx2x: Fix NULL pointer dereference in bnx2x_del_all_vlans() on some hw
  net/net_namespace: Check the return value of register_pernet_subsys()
  net/netlink_compat: Fix a missing check of nla_parse_nested
  ieee802154: lowpan_header_create check must check daddr
  net/mlx4_core: drop useless LIST_HEAD
  mlxsw: spectrum: drop useless LIST_HEAD
  net/mlx5e: drop useless LIST_HEAD
  iptunnel: Set tun_flags in the iptunnel_metadata_reply from src
  net/mlx5e: fix semicolon.cocci warnings
  staging: octeon: fix build failure with XFRM enabled
  net: Revert recent Spectre-v1 patches.
  can: af_can: Fix Spectre v1 vulnerability
  packet: validate address length if non-zero
  nfc: af_nfc: Fix Spectre v1 vulnerability
  phonet: af_phonet: Fix Spectre v1 vulnerability
  net: core: Fix Spectre v1 vulnerability
  net: minor cleanup in skb_ext_add()
  net: drop the unused helper skb_ext_get()
  ...

4 files changed, 66 insertions, 24 deletions

diff --git a/drivers/net/ppp/ppp_async.c b/drivers/net/ppp/ppp_async.c
index bdc4d23627c5..b287bb811875 100644
--- a/drivers/net/ppp/ppp_async.c
+++ b/drivers/net/ppp/ppp_async.c
@@ -70,7 +70,7 @@ struct asyncppp {
 	struct tasklet_struct tsk;
 
 	refcount_t	refcnt;
-	struct semaphore dead_sem;
+	struct completion dead;
 	struct ppp_channel chan;	/* interface to generic ppp layer */
 	unsigned char	obuf[OBUFSIZE];
 };
@@ -148,7 +148,7 @@ static struct asyncppp *ap_get(struct tty_struct *tty)
 static void ap_put(struct asyncppp *ap)
 {
 	if (refcount_dec_and_test(&ap->refcnt))
-		up(&ap->dead_sem);
+		complete(&ap->dead);
 }
 
 /*
@@ -186,7 +186,7 @@ ppp_asynctty_open(struct tty_struct *tty)
 	tasklet_init(&ap->tsk, ppp_async_process, (unsigned long) ap);
 
 	refcount_set(&ap->refcnt, 1);
-	sema_init(&ap->dead_sem, 0);
+	init_completion(&ap->dead);
 
 	ap->chan.private = ap;
 	ap->chan.ops = &async_ops;
@@ -235,7 +235,7 @@ ppp_asynctty_close(struct tty_struct *tty)
 	 * by the time it returns.
 	 */
 	if (!refcount_dec_and_test(&ap->refcnt))
-		down(&ap->dead_sem);
+		wait_for_completion(&ap->dead);
 	tasklet_kill(&ap->tsk);
 
 	ppp_unregister_channel(&ap->chan);
@@ -770,7 +770,7 @@ process_input_packet(struct asyncppp *ap)
 {
 	struct sk_buff *skb;
 	unsigned char *p;
-	unsigned int len, fcs, proto;
+	unsigned int len, fcs;
 
 	skb = ap->rpkt;
 	if (ap->state & (SC_TOSS | SC_ESCAPE))
@@ -799,14 +799,14 @@ process_input_packet(struct asyncppp *ap)
 			goto err;
 		p = skb_pull(skb, 2);
 	}
-	proto = p[0];
-	if (proto & 1) {
-		/* protocol is compressed */
-		*(u8 *)skb_push(skb, 1) = 0;
-	} else {
+
+	/* If protocol field is not compressed, it can be LCP packet */
+	if (!(p[0] & 0x01)) {
+		unsigned int proto;
+
 		if (skb->len < 2)
 			goto err;
-		proto = (proto << 8) + p[1];
+		proto = (p[0] << 8) + p[1];
 		if (proto == PPP_LCP)
 			async_lcp_peek(ap, p, skb->len, 1);
 	}
diff --git a/drivers/net/ppp/ppp_generic.c b/drivers/net/ppp/ppp_generic.c
index 500bc0027c1b..c708400fff4a 100644
--- a/drivers/net/ppp/ppp_generic.c
+++ b/drivers/net/ppp/ppp_generic.c
@@ -1965,6 +1965,46 @@ ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
 	ppp_recv_unlock(ppp);
 }
 
+/**
+ * __ppp_decompress_proto - Decompress protocol field, slim version.
+ * @skb: Socket buffer where protocol field should be decompressed. It must have
+ *	 at least 1 byte of head room and 1 byte of linear data. First byte of
+ *	 data must be a protocol field byte.
+ *
+ * Decompress protocol field in PPP header if it's compressed, e.g. when
+ * Protocol-Field-Compression (PFC) was negotiated. No checks w.r.t. skb data
+ * length are done in this function.
+ */
+static void __ppp_decompress_proto(struct sk_buff *skb)
+{
+	if (skb->data[0] & 0x01)
+		*(u8 *)skb_push(skb, 1) = 0x00;
+}
+
+/**
+ * ppp_decompress_proto - Check skb data room and decompress protocol field.
+ * @skb: Socket buffer where protocol field should be decompressed. First byte
+ *	 of data must be a protocol field byte.
+ *
+ * Decompress protocol field in PPP header if it's compressed, e.g. when
+ * Protocol-Field-Compression (PFC) was negotiated. This function also makes
+ * sure that skb data room is sufficient for Protocol field, before and after
+ * decompression.
+ *
+ * Return: true - decompressed successfully, false - not enough room in skb.
+ */
+static bool ppp_decompress_proto(struct sk_buff *skb)
+{
+	/* At least one byte should be present (if protocol is compressed) */
+	if (!pskb_may_pull(skb, 1))
+		return false;
+
+	__ppp_decompress_proto(skb);
+
+	/* Protocol field should occupy 2 bytes when not compressed */
+	return pskb_may_pull(skb, 2);
+}
+
 void
 ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
 {
@@ -1977,7 +2017,7 @@ ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
 	}
 
 	read_lock_bh(&pch->upl);
-	if (!pskb_may_pull(skb, 2)) {
+	if (!ppp_decompress_proto(skb)) {
 		kfree_skb(skb);
 		if (pch->ppp) {
 			++pch->ppp->dev->stats.rx_length_errors;
@@ -2074,6 +2114,9 @@ ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
 	if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR)
 		goto err;
 
+	/* At this point the "Protocol" field MUST be decompressed, either in
+	 * ppp_input(), ppp_decompress_frame() or in ppp_receive_mp_frame().
+	 */
 	proto = PPP_PROTO(skb);
 	switch (proto) {
 	case PPP_VJC_COMP:
@@ -2245,6 +2288,9 @@ ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
 		skb_put(skb, len);
 		skb_pull(skb, 2);	/* pull off the A/C bytes */
 
+		/* Don't call __ppp_decompress_proto() here, but instead rely on
+		 * corresponding algo (mppe/bsd/deflate) to decompress it.
+		 */
 	} else {
 		/* Uncompressed frame - pass to decompressor so it
 		   can update its dictionary if necessary. */
@@ -2290,9 +2336,11 @@ ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
 
 	/*
 	 * Do protocol ID decompression on the first fragment of each packet.
+	 * We have to do that here, because ppp_receive_nonmp_frame() expects
+	 * decompressed protocol field.
 	 */
-	if ((PPP_MP_CB(skb)->BEbits & B) && (skb->data[0] & 1))
-		*(u8 *)skb_push(skb, 1) = 0;
+	if (PPP_MP_CB(skb)->BEbits & B)
+		__ppp_decompress_proto(skb);
 
 	/*
 	 * Expand sequence number to 32 bits, making it as close
diff --git a/drivers/net/ppp/ppp_synctty.c b/drivers/net/ppp/ppp_synctty.c
index 047f6c68a441..d02ba2494d93 100644
--- a/drivers/net/ppp/ppp_synctty.c
+++ b/drivers/net/ppp/ppp_synctty.c
@@ -709,11 +709,10 @@ ppp_sync_input(struct syncppp *ap, const unsigned char *buf,
 		p = skb_pull(skb, 2);
 	}
 
-	/* decompress protocol field if compressed */
-	if (p[0] & 1) {
-		/* protocol is compressed */
-		*(u8 *)skb_push(skb, 1) = 0;
-	} else if (skb->len < 2)
+	/* PPP packet length should be >= 2 bytes when protocol field is not
+	 * compressed.
+	 */
+	if (!(p[0] & 0x01) && skb->len < 2)
 		goto err;
 
 	/* queue the frame to be processed */
diff --git a/drivers/net/ppp/pptp.c b/drivers/net/ppp/pptp.c
index 67ffe74747a1..8f09edd811e9 100644
--- a/drivers/net/ppp/pptp.c
+++ b/drivers/net/ppp/pptp.c
@@ -325,11 +325,6 @@ allow_packet:
 			skb_pull(skb, 2);
 		}
 
-		if ((*skb->data) & 1) {
-			/* protocol is compressed */
-			*(u8 *)skb_push(skb, 1) = 0;
-		}
-
 		skb->ip_summed = CHECKSUM_NONE;
 		skb_set_network_header(skb, skb->head-skb->data);
 		ppp_input(&po->chan, skb);