patch 'net/null: fix packet copy' has been queued to stable release 24.11.3

[Kevin Traynor]

Hi,

FYI, your patch has been queued to stable release 24.11.3

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 07/23/25. So please
shout if anyone has objections.

Also note that after the patch there's a diff of the upstream commit vs the
patch applied to the branch. This will indicate if there was any rebasing
needed to apply to the stable branch. If there were code changes for rebasing
(ie: not only metadata diffs), please double check that the rebase was
correctly done.

Queued patches are on a temporary branch at:
https://github.com/kevintraynor/dpdk-stable

This queued commit can be viewed at:
https://github.com/kevintraynor/dpdk-stable/commit/37a49c7d679abb72f5d9b705b3a6325962818df1

Thanks.

Kevin

---
>From 37a49c7d679abb72f5d9b705b3a6325962818df1 Mon Sep 17 00:00:00 2001
From: Stephen Hemminger <stephen at networkplumber.org>
Date: Tue, 1 Apr 2025 16:47:26 -0700
Subject: [PATCH] net/null: fix packet copy

[ upstream commit 0ffd3bc09be5f77b26c16e501e4b4465b1bcb8da ]

If doing copy on transmit, can potentially copy paste the data
in the mbuf. Change to only copy data from that segment.

Fixes: c743e50c475f ("null: new poll mode driver")

Signed-off-by: Stephen Hemminger <stephen at networkplumber.org>
---
 drivers/net/null/rte_eth_null.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/net/null/rte_eth_null.c b/drivers/net/null/rte_eth_null.c
index 6764cf2ec1..966748689f 100644
--- a/drivers/net/null/rte_eth_null.c
+++ b/drivers/net/null/rte_eth_null.c
@@ -36,5 +36,5 @@ struct null_queue {
 
 	struct rte_mempool *mb_pool;
-	struct rte_mbuf *dummy_packet;
+	void *dummy_packet;
 
 	RTE_ATOMIC(uint64_t) rx_pkts;
@@ -164,15 +164,15 @@ static uint16_t
 eth_null_copy_tx(void *q, struct rte_mbuf **bufs, uint16_t nb_bufs)
 {
-	int i;
 	struct null_queue *h = q;
-	unsigned int packet_size;
+	unsigned int i;
 
 	if ((q == NULL) || (bufs == NULL))
 		return 0;
 
-	packet_size = h->internals->packet_size;
 	for (i = 0; i < nb_bufs; i++) {
-		rte_memcpy(h->dummy_packet, rte_pktmbuf_mtod(bufs[i], void *),
-					packet_size);
+		struct rte_mbuf *m = bufs[i];
+		size_t len = RTE_MIN(h->internals->packet_size, m->data_len);
+
+		rte_memcpy(h->dummy_packet, rte_pktmbuf_mtod(m, void *), len);
 		rte_pktmbuf_free(bufs[i]);
 	}
-- 
2.50.0

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2025-07-18 20:29:12.928882707 +0100
+++ 0053-net-null-fix-packet-copy.patch	2025-07-18 20:29:10.933907340 +0100
@@ -1 +1 @@
-From 0ffd3bc09be5f77b26c16e501e4b4465b1bcb8da Mon Sep 17 00:00:00 2001
+From 37a49c7d679abb72f5d9b705b3a6325962818df1 Mon Sep 17 00:00:00 2001
@@ -5,0 +6,2 @@
+[ upstream commit 0ffd3bc09be5f77b26c16e501e4b4465b1bcb8da ]
+
@@ -10 +11,0 @@
-Cc: stable at dpdk.org