Merge tag 'net-6.1-rc3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Pull networking fixes from Jakub Kicinski:
 "Including fixes from bpf.

  The net-memcg fix stands out, the rest is very run-off-the-mill. Maybe
  I'm biased.

  Current release - regressions:

   - eth: fman: re-expose location of the MAC address to userspace,
     apparently some udev scripts depended on the exact value

  Current release - new code bugs:

   - bpf:
       - wait for busy refill_work when destroying bpf memory allocator
       - allow bpf_user_ringbuf_drain() callbacks to return 1
       - fix dispatcher patchable function entry to 5 bytes nop

  Previous releases - regressions:

   - net-memcg: avoid stalls when under memory pressure

   - tcp: fix indefinite deferral of RTO with SACK reneging

   - tipc: fix a null-ptr-deref in tipc_topsrv_accept

   - eth: macb: specify PHY PM management done by MAC

   - tcp: fix a signed-integer-overflow bug in tcp_add_backlog()

  Previous releases - always broken:

   - eth: amd-xgbe: SFP fixes and compatibility improvements

  Misc:

   - docs: netdev: offer performance feedback to contributors"

* tag 'net-6.1-rc3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (37 commits)
  net-memcg: avoid stalls when under memory pressure
  tcp: fix indefinite deferral of RTO with SACK reneging
  tcp: fix a signed-integer-overflow bug in tcp_add_backlog()
  net: lantiq_etop: don't free skb when returning NETDEV_TX_BUSY
  net: fix UAF issue in nfqnl_nf_hook_drop() when ops_init() failed
  docs: netdev: offer performance feedback to contributors
  kcm: annotate data-races around kcm->rx_wait
  kcm: annotate data-races around kcm->rx_psock
  net: fman: Use physical address for userspace interfaces
  net/mlx5e: Cleanup MACsec uninitialization routine
  atlantic: fix deadlock at aq_nic_stop
  nfp: only clean `sp_indiff` when application firmware is unloaded
  amd-xgbe: add the bit rate quirk for Molex cables
  amd-xgbe: fix the SFP compliance codes check for DAC cables
  amd-xgbe: enable PLL_CTL for fixed PHY modes only
  amd-xgbe: use enums for mailbox cmd and sub_cmds
  amd-xgbe: Yellow carp devices do not need rrc
  bpf: Use __llist_del_all() whenever possbile during memory draining
  bpf: Wait for busy refill_work when destroying bpf memory allocator
  MAINTAINERS: add keyword match on PTP
  ...

1 files changed, 15 insertions, 8 deletions

diff --git a/net/kcm/kcmsock.c b/net/kcm/kcmsock.c
index 27725464ec08..63e32f181f43 100644
--- a/net/kcm/kcmsock.c
+++ b/net/kcm/kcmsock.c
@@ -162,7 +162,8 @@ static void kcm_rcv_ready(struct kcm_sock *kcm)
 	/* Buffer limit is okay now, add to ready list */
 	list_add_tail(&kcm->wait_rx_list,
 		      &kcm->mux->kcm_rx_waiters);
-	kcm->rx_wait = true;
+	/* paired with lockless reads in kcm_rfree() */
+	WRITE_ONCE(kcm->rx_wait, true);
 }
 
 static void kcm_rfree(struct sk_buff *skb)
@@ -178,7 +179,7 @@ static void kcm_rfree(struct sk_buff *skb)
 	/* For reading rx_wait and rx_psock without holding lock */
 	smp_mb__after_atomic();
 
-	if (!kcm->rx_wait && !kcm->rx_psock &&
+	if (!READ_ONCE(kcm->rx_wait) && !READ_ONCE(kcm->rx_psock) &&
 	    sk_rmem_alloc_get(sk) < sk->sk_rcvlowat) {
 		spin_lock_bh(&mux->rx_lock);
 		kcm_rcv_ready(kcm);
@@ -237,7 +238,8 @@ try_again:
 		if (kcm_queue_rcv_skb(&kcm->sk, skb)) {
 			/* Should mean socket buffer full */
 			list_del(&kcm->wait_rx_list);
-			kcm->rx_wait = false;
+			/* paired with lockless reads in kcm_rfree() */
+			WRITE_ONCE(kcm->rx_wait, false);
 
 			/* Commit rx_wait to read in kcm_free */
 			smp_wmb();
@@ -280,10 +282,12 @@ static struct kcm_sock *reserve_rx_kcm(struct kcm_psock *psock,
 	kcm = list_first_entry(&mux->kcm_rx_waiters,
 			       struct kcm_sock, wait_rx_list);
 	list_del(&kcm->wait_rx_list);
-	kcm->rx_wait = false;
+	/* paired with lockless reads in kcm_rfree() */
+	WRITE_ONCE(kcm->rx_wait, false);
 
 	psock->rx_kcm = kcm;
-	kcm->rx_psock = psock;
+	/* paired with lockless reads in kcm_rfree() */
+	WRITE_ONCE(kcm->rx_psock, psock);
 
 	spin_unlock_bh(&mux->rx_lock);
 
@@ -310,7 +314,8 @@ static void unreserve_rx_kcm(struct kcm_psock *psock,
 	spin_lock_bh(&mux->rx_lock);
 
 	psock->rx_kcm = NULL;
-	kcm->rx_psock = NULL;
+	/* paired with lockless reads in kcm_rfree() */
+	WRITE_ONCE(kcm->rx_psock, NULL);
 
 	/* Commit kcm->rx_psock before sk_rmem_alloc_get to sync with
 	 * kcm_rfree
@@ -1240,7 +1245,8 @@ static void kcm_recv_disable(struct kcm_sock *kcm)
 	if (!kcm->rx_psock) {
 		if (kcm->rx_wait) {
 			list_del(&kcm->wait_rx_list);
-			kcm->rx_wait = false;
+			/* paired with lockless reads in kcm_rfree() */
+			WRITE_ONCE(kcm->rx_wait, false);
 		}
 
 		requeue_rx_msgs(mux, &kcm->sk.sk_receive_queue);
@@ -1793,7 +1799,8 @@ static void kcm_done(struct kcm_sock *kcm)
 
 	if (kcm->rx_wait) {
 		list_del(&kcm->wait_rx_list);
-		kcm->rx_wait = false;
+		/* paired with lockless reads in kcm_rfree() */
+		WRITE_ONCE(kcm->rx_wait, false);
 	}
 	/* Move any pending receive messages to other kcm sockets */
 	requeue_rx_msgs(mux, &sk->sk_receive_queue);