Merge tag 'net-6.14-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Pull networking fixes from Paolo Abeni:
 "Including fixes from bluetooth and wireless.

  Current release - new code bugs:

   - wifi: nl80211: disable multi-link reconfiguration

  Previous releases - regressions:

   - gso: fix ownership in __udp_gso_segment

   - wifi: iwlwifi:
      - fix A-MSDU TSO preparation
      - free pages allocated when failing to build A-MSDU

   - ipv6: fix dst ref loop in ila lwtunnel

   - mptcp: fix 'scheduling while atomic' in
     mptcp_pm_nl_append_new_local_addr

   - bluetooth: add check for mgmt_alloc_skb() in
     mgmt_device_connected()

   - ethtool: allow NULL nlattrs when getting a phy_device

   - eth: be2net: fix sleeping while atomic bugs in
     be_ndo_bridge_getlink

  Previous releases - always broken:

   - core: support TCP GSO case for a few missing flags

   - wifi: mac80211:
      - fix vendor-specific inheritance
      - cleanup sta TXQs on flush

   - llc: do not use skb_get() before dev_queue_xmit()

   - eth: ipa: nable checksum for IPA_ENDPOINT_AP_MODEM_{RX,TX}
     for v4.7"

* tag 'net-6.14-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (41 commits)
  net: ipv6: fix missing dst ref drop in ila lwtunnel
  net: ipv6: fix dst ref loop in ila lwtunnel
  mctp i3c: handle NULL header address
  net: dsa: mt7530: Fix traffic flooding for MMIO devices
  net-timestamp: support TCP GSO case for a few missing flags
  vlan: enforce underlying device type
  mptcp: fix 'scheduling while atomic' in mptcp_pm_nl_append_new_local_addr
  net: ethtool: netlink: Allow NULL nlattrs when getting a phy_device
  ppp: Fix KMSAN uninit-value warning with bpf
  net: ipa: Enable checksum for IPA_ENDPOINT_AP_MODEM_{RX,TX} for v4.7
  net: ipa: Fix QSB data for v4.7
  net: ipa: Fix v4.7 resource group names
  net: hns3: make sure ptp clock is unregister and freed if hclge_ptp_get_cycle returns an error
  wifi: nl80211: disable multi-link reconfiguration
  net: dsa: rtl8366rb: don't prompt users for LED control
  be2net: fix sleeping while atomic bugs in be_ndo_bridge_getlink
  llc: do not use skb_get() before dev_queue_xmit()
  wifi: cfg80211: regulatory: improve invalid hints checking
  caif_virtio: fix wrong pointer check in cfv_probe()
  net: gso: fix ownership in __udp_gso_segment
  ...

1 files changed, 19 insertions, 9 deletions

diff --git a/drivers/net/ppp/ppp_generic.c b/drivers/net/ppp/ppp_generic.c
index 4583e15ad03a..1420c4efa48e 100644
--- a/drivers/net/ppp/ppp_generic.c
+++ b/drivers/net/ppp/ppp_generic.c
@@ -72,6 +72,17 @@
 #define PPP_PROTO_LEN	2
 #define PPP_LCP_HDRLEN	4
 
+/* The filter instructions generated by libpcap are constructed
+ * assuming a four-byte PPP header on each packet, where the last
+ * 2 bytes are the protocol field defined in the RFC and the first
+ * byte of the first 2 bytes indicates the direction.
+ * The second byte is currently unused, but we still need to initialize
+ * it to prevent crafted BPF programs from reading them which would
+ * cause reading of uninitialized data.
+ */
+#define PPP_FILTER_OUTBOUND_TAG 0x0100
+#define PPP_FILTER_INBOUND_TAG  0x0000
+
 /*
  * An instance of /dev/ppp can be associated with either a ppp
  * interface unit or a ppp channel.  In both cases, file->private_data
@@ -1762,10 +1773,10 @@ ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
 
 	if (proto < 0x8000) {
 #ifdef CONFIG_PPP_FILTER
-		/* check if we should pass this packet */
-		/* the filter instructions are constructed assuming
-		   a four-byte PPP header on each packet */
-		*(u8 *)skb_push(skb, 2) = 1;
+		/* check if the packet passes the pass and active filters.
+		 * See comment for PPP_FILTER_OUTBOUND_TAG above.
+		 */
+		*(__be16 *)skb_push(skb, 2) = htons(PPP_FILTER_OUTBOUND_TAG);
 		if (ppp->pass_filter &&
 		    bpf_prog_run(ppp->pass_filter, skb) == 0) {
 			if (ppp->debug & 1)
@@ -2482,14 +2493,13 @@ ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
 		/* network protocol frame - give it to the kernel */
 
 #ifdef CONFIG_PPP_FILTER
-		/* check if the packet passes the pass and active filters */
-		/* the filter instructions are constructed assuming
-		   a four-byte PPP header on each packet */
 		if (ppp->pass_filter || ppp->active_filter) {
 			if (skb_unclone(skb, GFP_ATOMIC))
 				goto err;
-
-			*(u8 *)skb_push(skb, 2) = 0;
+			/* Check if the packet passes the pass and active filters.
+			 * See comment for PPP_FILTER_INBOUND_TAG above.
+			 */
+			*(__be16 *)skb_push(skb, 2) = htons(PPP_FILTER_INBOUND_TAG);
 			if (ppp->pass_filter &&
 			    bpf_prog_run(ppp->pass_filter, skb) == 0) {
 				if (ppp->debug & 1)