[3.16.y-ckt stable] Patch "hyperv: Fix the error processing in netvsc_send()" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    hyperv: Fix the error processing in netvsc_send()

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt7.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 390d17c7d3026d913ccf86455df5e1a3aea2a1d5 Mon Sep 17 00:00:00 2001
From: Haiyang Zhang <haiyangz at microsoft.com>
Date: Thu, 29 Jan 2015 12:34:49 -0800
Subject: hyperv: Fix the error processing in netvsc_send()

commit d953ca4ddf71aa91a4596b2ff7ff1598f6ad4708 upstream.

The existing code frees the skb in EAGAIN case, in which the skb will be
retried from upper layer and used again.
Also, the existing code doesn't free send buffer slot in error case, because
there is no completion message for unsent packets.
This patch fixes these problems.

(Please also include this patch for stable trees. Thanks!)

Signed-off-by: Haiyang Zhang <haiyangz at microsoft.com>
Reviewed-by: K. Y. Srinivasan <kys at microsoft.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/net/hyperv/netvsc.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c
index 7edf976ecfa0..349fb3d73f30 100644
--- a/drivers/net/hyperv/netvsc.c
+++ b/drivers/net/hyperv/netvsc.c
@@ -707,7 +707,7 @@ int netvsc_send(struct hv_device *device,
 	u64 req_id;
 	unsigned int section_index = NETVSC_INVALID_INDEX;
 	u32 msg_size = 0;
-	struct sk_buff *skb;
+	struct sk_buff *skb = NULL;
 	u16 q_idx = packet->q_idx;


@@ -734,8 +734,6 @@ int netvsc_send(struct hv_device *device,
 							   packet);
 			skb = (struct sk_buff *)
 			      (unsigned long)packet->send_completion_tid;
-			if (skb)
-				dev_kfree_skb_any(skb);
 			packet->page_buf_cnt = 0;
 		}
 	}
@@ -798,6 +796,13 @@ int netvsc_send(struct hv_device *device,
 			   packet, ret);
 	}

+	if (ret != 0) {
+		if (section_index != NETVSC_INVALID_INDEX)
+			netvsc_free_send_slot(net_device, section_index);
+	} else if (skb) {
+		dev_kfree_skb_any(skb);
+	}
+
 	return ret;
 }

--
2.1.4