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

Pull networking fixes from David Miller:

 1) Account for extra headroom in ath9k driver, from Felix Fietkau.

 2) Fix OOPS in pppoe driver due to incorrect socket state transition,
    from Guillaume Nault.

 3) Kill memory leak in amd-xgbe debugfx, from Geliang Tang.

 4) Power management fixes for iwlwifi, from Johannes Berg.

 5) Fix races in reqsk_queue_unlink(), from Eric Dumazet.

 6) Fix dst_entry usage in ARP replies, from Jiri Benc.

 7) Cure OOPSes with SO_GET_FILTER, from Daniel Borkmann.

 8) Missing allocation failure check in amd-xgbe, from Tom Lendacky.

 9) Various resource allocation/freeing cures in DSA< from Neil
    Armstrong.

10) A series of bug fixes in the openvswitch conntrack support, from
    Joe Stringer.

11) Fix two cases (BPF and act_mirred) where we have to clean the sender
    cpu stored in the SKB before transmitting.  From WANG Cong and
    Alexei Starovoitov.

12) Disable VLAN filtering in promiscuous mode in mlx5 driver, from
    Achiad Shochat.

13) Older bnx2x chips cannot do 4-tuple UDP hashing, so prevent this
    configuration via ethtool.  From Yuval Mintz.

14) Don't call rt6_uncached_list_flush_dev() from rt6_ifdown() when
    'dev' is NULL, from Eric Biederman.

15) Prevent stalled link synchronization in tipc, from Jon Paul Maloy.

16) kcalloc() gstrings ethtool buffer before having driver fill it in,
    in order to prevent kernel memory leaking.  From Joe Perches.

17) Fix mixxing rt6_info initialization for blackhole routes, from
    Martin KaFai Lau.

18) Kill VLAN regression in via-rhine, from Andrej Ota.

19) Missing pfmemalloc check in sk_add_backlog(), from Eric Dumazet.

20) Fix spurious MSG_TRUNC signalling in netlink dumps, from Ronen Arad.

21) Scrube SKBs when pushing them between namespaces in openvswitch,
    from Joe Stringer.

22) bcmgenet enables link interrupts too early, fix from Florian
    Fainelli.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (92 commits)
  net: bcmgenet: Fix early link interrupt enabling
  tunnels: Don't require remote endpoint or ID during creation.
  openvswitch: Scrub skb between namespaces
  xen-netback: correctly check failed allocation
  net: asix: add support for the Billionton GUSB2AM-1G-B USB adapter
  netlink: Trim skb to alloc size to avoid MSG_TRUNC
  net: add pfmemalloc check in sk_add_backlog()
  via-rhine: fix VLAN receive handling regression.
  ipv6: Initialize rt6_info properly in ip6_blackhole_route()
  ipv6: Move common init code for rt6_info to a new function rt6_info_init()
  Bluetooth: Fix initializing conn_params in scan phase
  Bluetooth: Fix conn_params list update in hci_connect_le_scan_cleanup
  Bluetooth: Fix remove_device behavior for explicit connects
  Bluetooth: Fix LE reconnection logic
  Bluetooth: Fix reference counting for LE-scan based connections
  Bluetooth: Fix double scan updates
  mlxsw: core: Fix race condition in __mlxsw_emad_transmit
  tipc: move fragment importance field to new header position
  ethtool: Use kcalloc instead of kmalloc for ethtool_get_strings
  tipc: eliminate risk of stalled link synchronization
  ...

1 files changed, 22 insertions, 12 deletions

diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index 8f060d7f9a0e..0a49a8c7c564 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -2785,6 +2785,7 @@ static int netlink_dump(struct sock *sk)
 	struct sk_buff *skb = NULL;
 	struct nlmsghdr *nlh;
 	int len, err = -ENOBUFS;
+	int alloc_min_size;
 	int alloc_size;
 
 	mutex_lock(nlk->cb_mutex);
@@ -2793,9 +2794,6 @@ static int netlink_dump(struct sock *sk)
 		goto errout_skb;
 	}
 
-	cb = &nlk->cb;
-	alloc_size = max_t(int, cb->min_dump_alloc, NLMSG_GOODSIZE);
-
 	if (!netlink_rx_is_mmaped(sk) &&
 	    atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
 		goto errout_skb;
@@ -2805,23 +2803,35 @@ static int netlink_dump(struct sock *sk)
 	 * to reduce number of system calls on dump operations, if user
 	 * ever provided a big enough buffer.
 	 */
-	if (alloc_size < nlk->max_recvmsg_len) {
-		skb = netlink_alloc_skb(sk,
-					nlk->max_recvmsg_len,
-					nlk->portid,
+	cb = &nlk->cb;
+	alloc_min_size = max_t(int, cb->min_dump_alloc, NLMSG_GOODSIZE);
+
+	if (alloc_min_size < nlk->max_recvmsg_len) {
+		alloc_size = nlk->max_recvmsg_len;
+		skb = netlink_alloc_skb(sk, alloc_size, nlk->portid,
 					GFP_KERNEL |
 					__GFP_NOWARN |
 					__GFP_NORETRY);
-		/* available room should be exact amount to avoid MSG_TRUNC */
-		if (skb)
-			skb_reserve(skb, skb_tailroom(skb) -
-					 nlk->max_recvmsg_len);
 	}
-	if (!skb)
+	if (!skb) {
+		alloc_size = alloc_min_size;
 		skb = netlink_alloc_skb(sk, alloc_size, nlk->portid,
 					GFP_KERNEL);
+	}
 	if (!skb)
 		goto errout_skb;
+
+	/* Trim skb to allocated size. User is expected to provide buffer as
+	 * large as max(min_dump_alloc, 16KiB (mac_recvmsg_len capped at
+	 * netlink_recvmsg())). dump will pack as many smaller messages as
+	 * could fit within the allocated skb. skb is typically allocated
+	 * with larger space than required (could be as much as near 2x the
+	 * requested size with align to next power of 2 approach). Allowing
+	 * dump to use the excess space makes it difficult for a user to have a
+	 * reasonable static buffer based on the expected largest dump of a
+	 * single netdev. The outcome is MSG_TRUNC error.
+	 */
+	skb_reserve(skb, skb_tailroom(skb) - alloc_size);
 	netlink_skb_set_owner_r(skb, sk);
 
 	len = cb->dump(skb, cb);