patch 'net/tap: avoid memcpy with null argument' has been queued to stable release 22.11.7

[luca.boccassi at gmail.com]

Hi,

FYI, your patch has been queued to stable release 22.11.7

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 10/25/24. 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/bluca/dpdk-stable

This queued commit can be viewed at:
https://github.com/bluca/dpdk-stable/commit/8b8b03abd8b14c9b3d42d2808a02a6161a36ef8b

Thanks.

Luca Boccassi

---
>From 8b8b03abd8b14c9b3d42d2808a02a6161a36ef8b Mon Sep 17 00:00:00 2001
From: Stephen Hemminger <stephen at networkplumber.org>
Date: Tue, 13 Aug 2024 19:34:16 -0700
Subject: [PATCH] net/tap: avoid memcpy with null argument

[ upstream commit 3975d85fb8606308ccdb6439b35f70e8733a78e8 ]

Calling memcpy with a null pointer even if zero length is
undefined, so check if data_length is zero.
Problem reported by Gcc analyzer.

Fixes: 7c25284e30c2 ("net/tap: add netlink back-end for flow API")

Signed-off-by: Stephen Hemminger <stephen at networkplumber.org>
Acked-by: Ferruh Yigit <ferruh.yigit at amd.com>
---
 drivers/net/tap/tap_netlink.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/tap/tap_netlink.c b/drivers/net/tap/tap_netlink.c
index d9c260127d..35c491ac37 100644
--- a/drivers/net/tap/tap_netlink.c
+++ b/drivers/net/tap/tap_netlink.c
@@ -302,7 +302,8 @@ tap_nlattr_add(struct nlmsghdr *nh, unsigned short type,
 	rta = (struct rtattr *)NLMSG_TAIL(nh);
 	rta->rta_len = RTA_LENGTH(data_len);
 	rta->rta_type = type;
-	memcpy(RTA_DATA(rta), data, data_len);
+	if (data_len > 0)
+		memcpy(RTA_DATA(rta), data, data_len);
 	nh->nlmsg_len = NLMSG_ALIGN(nh->nlmsg_len) + RTA_ALIGN(rta->rta_len);
 }
 
-- 
2.45.2

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2024-10-23 22:16:42.331354752 +0100
+++ 0048-net-tap-avoid-memcpy-with-null-argument.patch	2024-10-23 22:16:40.499942740 +0100
@@ -1 +1 @@
-From 3975d85fb8606308ccdb6439b35f70e8733a78e8 Mon Sep 17 00:00:00 2001
+From 8b8b03abd8b14c9b3d42d2808a02a6161a36ef8b Mon Sep 17 00:00:00 2001
@@ -5,0 +6,2 @@
+[ upstream commit 3975d85fb8606308ccdb6439b35f70e8733a78e8 ]
+
@@ -11 +12,0 @@
-Cc: stable at dpdk.org