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

Pull networking fixes from David Miller:

 1) BPF sample build fixes from Björn Töpel

 2) Fix powerpc bpf tail call implementation, from Eric Dumazet.

 3) DCCP leaks jiffies on the wire, fix also from Eric Dumazet.

 4) Fix crash in ebtables when using dnat target, from Florian Westphal.

 5) Fix port disable handling whne removing bcm_sf2 driver, from Florian
    Fainelli.

 6) Fix kTLS sk_msg trim on fallback to copy mode, from Jakub Kicinski.

 7) Various KCSAN fixes all over the networking, from Eric Dumazet.

 8) Memory leaks in mlx5 driver, from Alex Vesker.

 9) SMC interface refcounting fix, from Ursula Braun.

10) TSO descriptor handling fixes in stmmac driver, from Jose Abreu.

11) Add a TX lock to synchonize the kTLS TX path properly with crypto
    operations. From Jakub Kicinski.

12) Sock refcount during shutdown fix in vsock/virtio code, from Stefano
    Garzarella.

13) Infinite loop in Intel ice driver, from Colin Ian King.

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (108 commits)
  ixgbe: need_wakeup flag might not be set for Tx
  i40e: need_wakeup flag might not be set for Tx
  igb/igc: use ktime accessors for skb->tstamp
  i40e: Fix for ethtool -m issue on X722 NIC
  iavf: initialize ITRN registers with correct values
  ice: fix potential infinite loop because loop counter being too small
  qede: fix NULL pointer deref in __qede_remove()
  net: fix data-race in neigh_event_send()
  vsock/virtio: fix sock refcnt holding during the shutdown
  net: ethernet: octeon_mgmt: Account for second possible VLAN header
  mac80211: fix station inactive_time shortly after boot
  net/fq_impl: Switch to kvmalloc() for memory allocation
  mac80211: fix ieee80211_txq_setup_flows() failure path
  ipv4: Fix table id reference in fib_sync_down_addr
  ipv6: fixes rt6_probe() and fib6_nh->last_probe init
  net: hns: Fix the stray netpoll locks causing deadlock in NAPI path
  net: usb: qmi_wwan: add support for DW5821e with eSIM support
  CDC-NCM: handle incomplete transfer of MTU
  nfc: netlink: fix double device reference drop
  NFC: st21nfca: fix double free
  ...

1 files changed, 85 insertions, 17 deletions

diff --git a/drivers/net/can/rx-offload.c b/drivers/net/can/rx-offload.c
index e6a668ee7730..84cae167e42f 100644
--- a/drivers/net/can/rx-offload.c
+++ b/drivers/net/can/rx-offload.c
@@ -107,37 +107,95 @@ static int can_rx_offload_compare(struct sk_buff *a, struct sk_buff *b)
 	return cb_b->timestamp - cb_a->timestamp;
 }
 
-static struct sk_buff *can_rx_offload_offload_one(struct can_rx_offload *offload, unsigned int n)
+/**
+ * can_rx_offload_offload_one() - Read one CAN frame from HW
+ * @offload: pointer to rx_offload context
+ * @n: number of mailbox to read
+ *
+ * The task of this function is to read a CAN frame from mailbox @n
+ * from the device and return the mailbox's content as a struct
+ * sk_buff.
+ *
+ * If the struct can_rx_offload::skb_queue exceeds the maximal queue
+ * length (struct can_rx_offload::skb_queue_len_max) or no skb can be
+ * allocated, the mailbox contents is discarded by reading it into an
+ * overflow buffer. This way the mailbox is marked as free by the
+ * driver.
+ *
+ * Return: A pointer to skb containing the CAN frame on success.
+ *
+ *         NULL if the mailbox @n is empty.
+ *
+ *         ERR_PTR() in case of an error
+ */
+static struct sk_buff *
+can_rx_offload_offload_one(struct can_rx_offload *offload, unsigned int n)
 {
-	struct sk_buff *skb = NULL;
+	struct sk_buff *skb = NULL, *skb_error = NULL;
 	struct can_rx_offload_cb *cb;
 	struct can_frame *cf;
 	int ret;
 
-	/* If queue is full or skb not available, read to discard mailbox */
-	if (likely(skb_queue_len(&offload->skb_queue) <=
-		   offload->skb_queue_len_max))
+	if (likely(skb_queue_len(&offload->skb_queue) <
+		   offload->skb_queue_len_max)) {
 		skb = alloc_can_skb(offload->dev, &cf);
+		if (unlikely(!skb))
+			skb_error = ERR_PTR(-ENOMEM);	/* skb alloc failed */
+	} else {
+		skb_error = ERR_PTR(-ENOBUFS);		/* skb_queue is full */
+	}
 
-	if (!skb) {
+	/* If queue is full or skb not available, drop by reading into
+	 * overflow buffer.
+	 */
+	if (unlikely(skb_error)) {
 		struct can_frame cf_overflow;
 		u32 timestamp;
 
 		ret = offload->mailbox_read(offload, &cf_overflow,
 					    &timestamp, n);
-		if (ret)
-			offload->dev->stats.rx_dropped++;
 
-		return NULL;
+		/* Mailbox was empty. */
+		if (unlikely(!ret))
+			return NULL;
+
+		/* Mailbox has been read and we're dropping it or
+		 * there was a problem reading the mailbox.
+		 *
+		 * Increment error counters in any case.
+		 */
+		offload->dev->stats.rx_dropped++;
+		offload->dev->stats.rx_fifo_errors++;
+
+		/* There was a problem reading the mailbox, propagate
+		 * error value.
+		 */
+		if (unlikely(ret < 0))
+			return ERR_PTR(ret);
+
+		return skb_error;
 	}
 
 	cb = can_rx_offload_get_cb(skb);
 	ret = offload->mailbox_read(offload, cf, &cb->timestamp, n);
-	if (!ret) {
+
+	/* Mailbox was empty. */
+	if (unlikely(!ret)) {
 		kfree_skb(skb);
 		return NULL;
 	}
 
+	/* There was a problem reading the mailbox, propagate error value. */
+	if (unlikely(ret < 0)) {
+		kfree_skb(skb);
+
+		offload->dev->stats.rx_dropped++;
+		offload->dev->stats.rx_fifo_errors++;
+
+		return ERR_PTR(ret);
+	}
+
+	/* Mailbox was read. */
 	return skb;
 }
 
@@ -157,8 +215,8 @@ int can_rx_offload_irq_offload_timestamp(struct can_rx_offload *offload, u64 pen
 			continue;
 
 		skb = can_rx_offload_offload_one(offload, i);
-		if (!skb)
-			break;
+		if (IS_ERR_OR_NULL(skb))
+			continue;
 
 		__skb_queue_add_sort(&skb_queue, skb, can_rx_offload_compare);
 	}
@@ -188,7 +246,13 @@ int can_rx_offload_irq_offload_fifo(struct can_rx_offload *offload)
 	struct sk_buff *skb;
 	int received = 0;
 
-	while ((skb = can_rx_offload_offload_one(offload, 0))) {
+	while (1) {
+		skb = can_rx_offload_offload_one(offload, 0);
+		if (IS_ERR(skb))
+			continue;
+		if (!skb)
+			break;
+
 		skb_queue_tail(&offload->skb_queue, skb);
 		received++;
 	}
@@ -207,8 +271,10 @@ int can_rx_offload_queue_sorted(struct can_rx_offload *offload,
 	unsigned long flags;
 
 	if (skb_queue_len(&offload->skb_queue) >
-	    offload->skb_queue_len_max)
-		return -ENOMEM;
+	    offload->skb_queue_len_max) {
+		kfree_skb(skb);
+		return -ENOBUFS;
+	}
 
 	cb = can_rx_offload_get_cb(skb);
 	cb->timestamp = timestamp;
@@ -250,8 +316,10 @@ int can_rx_offload_queue_tail(struct can_rx_offload *offload,
 			      struct sk_buff *skb)
 {
 	if (skb_queue_len(&offload->skb_queue) >
-	    offload->skb_queue_len_max)
-		return -ENOMEM;
+	    offload->skb_queue_len_max) {
+		kfree_skb(skb);
+		return -ENOBUFS;
+	}
 
 	skb_queue_tail(&offload->skb_queue, skb);
 	can_rx_offload_schedule(offload);