Merge tag 'net-6.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netHEADtorvalds/mastertorvalds/HEADmaster

Pull networking fixes from Jakub Kicinski:
  Previous releases - regressions:

   - netlink: avoid infinite retry looping in netlink_unicast()

  Previous releases - always broken:

   - packet: fix a race in packet_set_ring() and packet_notifier()

   - ipv6: reject malicious packets in ipv6_gso_segment()

   - sched: mqprio: fix stack out-of-bounds write in tc entry parsing

   - net: drop UFO packets (injected via virtio) in udp_rcv_segment()

   - eth: mlx5: correctly set gso_segs when LRO is used, avoid false
     positive checksum validation errors

   - netpoll: prevent hanging NAPI when netcons gets enabled

   - phy: mscc: fix parsing of unicast frames for PTP timestamping

   - a number of device tree / OF reference leak fixes"

* tag 'net-6.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (44 commits)
  pptp: fix pptp_xmit() error path
  net: ti: icssg-prueth: Fix skb handling for XDP_PASS
  net: Update threaded state in napi config in netif_set_threaded
  selftests: netdevsim: Xfail nexthop test on slow machines
  eth: fbnic: Lock the tx_dropped update
  eth: fbnic: Fix tx_dropped reporting
  eth: fbnic: remove the debugging trick of super high page bias
  net: ftgmac100: fix potential NULL pointer access in ftgmac100_phy_disconnect
  dt-bindings: net: Replace bouncing Alexandru Tachici emails
  dpll: zl3073x: ZL3073X_I2C and ZL3073X_SPI should depend on NET
  net/sched: mqprio: fix stack out-of-bounds write in tc entry parsing
  Revert "net: mdio_bus: Use devm for getting reset GPIO"
  selftests: net: packetdrill: xfail all problems on slow machines
  net/packet: fix a race in packet_set_ring() and packet_notifier()
  benet: fix BUG when creating VFs
  net: airoha: npu: Add missing MODULE_FIRMWARE macros
  net: devmem: fix DMA direction on unmapping
  ipa: fix compile-testing with qcom-mdt=m
  eth: fbnic: unlink NAPIs from queues on error to open
  net: Add locking to protect skb->dev access in ip_output
  ...

1 files changed, 11 insertions, 7 deletions

diff --git a/drivers/net/ppp/pptp.c b/drivers/net/ppp/pptp.c
index 5feaa70b5f47..90737cb71892 100644
--- a/drivers/net/ppp/pptp.c
+++ b/drivers/net/ppp/pptp.c
@@ -159,19 +159,17 @@ static int pptp_xmit(struct ppp_channel *chan, struct sk_buff *skb)
 	int len;
 	unsigned char *data;
 	__u32 seq_recv;
-
-
 	struct rtable *rt;
 	struct net_device *tdev;
 	struct iphdr  *iph;
 	int    max_headroom;
 
 	if (sk_pppox(po)->sk_state & PPPOX_DEAD)
-		goto tx_error;
+		goto tx_drop;
 
 	rt = pptp_route_output(po, &fl4);
 	if (IS_ERR(rt))
-		goto tx_error;
+		goto tx_drop;
 
 	tdev = rt->dst.dev;
 
@@ -179,16 +177,20 @@ static int pptp_xmit(struct ppp_channel *chan, struct sk_buff *skb)
 
 	if (skb_headroom(skb) < max_headroom || skb_cloned(skb) || skb_shared(skb)) {
 		struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
-		if (!new_skb) {
-			ip_rt_put(rt);
+
+		if (!new_skb)
 			goto tx_error;
-		}
+
 		if (skb->sk)
 			skb_set_owner_w(new_skb, skb->sk);
 		consume_skb(skb);
 		skb = new_skb;
 	}
 
+	/* Ensure we can safely access protocol field and LCP code */
+	if (!pskb_may_pull(skb, 3))
+		goto tx_error;
+
 	data = skb->data;
 	islcp = ((data[0] << 8) + data[1]) == PPP_LCP && 1 <= data[2] && data[2] <= 7;
 
@@ -262,6 +264,8 @@ static int pptp_xmit(struct ppp_channel *chan, struct sk_buff *skb)
 	return 1;
 
 tx_error:
+	ip_rt_put(rt);
+tx_drop:
 	kfree_skb(skb);
 	return 1;
 }