Received-SPF: pass (google.com: domain of linux-nfs+bounces-2516-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.199.223 as permitted sender) client-ip=147.75.199.223;
From: Joel Granados via B4 Relay <devnull+j.granados.samsung.com@kernel.org>
Date: Thu, 28 Mar 2024 16:40:05 +0100
Subject: [PATCH v2 4/4] ax.25: Remove the now superfluous sentinel elements
 from ctl_table array
Precedence: bulk
MIME-Version: 1.0
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: 7bit
Message-Id: <20240328-jag-sysctl_remset_net-v2-4-52c9fad9a1af@samsung.com>
References: <20240328-jag-sysctl_remset_net-v2-0-52c9fad9a1af@samsung.com>
In-Reply-To: <20240328-jag-sysctl_remset_net-v2-0-52c9fad9a1af@samsung.com>
To: "David S. Miller" <davem@davemloft.net>, 
 Eric Dumazet <edumazet@google.com>, Jakub Kicinski <kuba@kernel.org>, 
 Paolo Abeni <pabeni@redhat.com>, Alexander Aring <alex.aring@gmail.com>, 
 Stefan Schmidt <stefan@datenfreihafen.org>, 
 Miquel Raynal <miquel.raynal@bootlin.com>, David Ahern <dsahern@kernel.org>, 
 Steffen Klassert <steffen.klassert@secunet.com>, 
 Herbert Xu <herbert@gondor.apana.org.au>, 
 Matthieu Baerts <matttbe@kernel.org>, Mat Martineau <martineau@kernel.org>, 
 Geliang Tang <geliang@kernel.org>, Ralf Baechle <ralf@linux-mips.org>, 
 Remi Denis-Courmont <courmisch@gmail.com>, 
 Allison Henderson <allison.henderson@oracle.com>, 
 David Howells <dhowells@redhat.com>, Marc Dionne <marc.dionne@auristor.com>, 
 Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>, 
 Xin Long <lucien.xin@gmail.com>, Wenjia Zhang <wenjia@linux.ibm.com>, 
 Jan Karcher <jaka@linux.ibm.com>, "D. Wythe" <alibuda@linux.alibaba.com>, 
 Tony Lu <tonylu@linux.alibaba.com>, Wen Gu <guwen@linux.alibaba.com>, 
 Trond Myklebust <trond.myklebust@hammerspace.com>, 
 Anna Schumaker <anna@kernel.org>, Chuck Lever <chuck.lever@oracle.com>, 
 Jeff Layton <jlayton@kernel.org>, Neil Brown <neilb@suse.de>, 
 Olga Kornievskaia <kolga@netapp.com>, Dai Ngo <Dai.Ngo@oracle.com>, 
 Tom Talpey <tom@talpey.com>, Jon Maloy <jmaloy@redhat.com>, 
 Ying Xue <ying.xue@windriver.com>, Martin Schiller <ms@dev.tdt.de>, 
 Pablo Neira Ayuso <pablo@netfilter.org>, 
 Jozsef Kadlecsik <kadlec@netfilter.org>, Florian Westphal <fw@strlen.de>, 
 Roopa Prabhu <roopa@nvidia.com>, Nikolay Aleksandrov <razor@blackwall.org>, 
 Simon Horman <horms@verge.net.au>, Julian Anastasov <ja@ssi.bg>, 
 Joerg Reuter <jreuter@yaina.de>, Luis Chamberlain <mcgrof@kernel.org>, 
 Kees Cook <keescook@chromium.org>
Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, 
 dccp@vger.kernel.org, linux-wpan@vger.kernel.org, mptcp@lists.linux.dev, 
 linux-hams@vger.kernel.org, linux-rdma@vger.kernel.org, 
 rds-devel@oss.oracle.com, linux-afs@lists.infradead.org, 
 linux-sctp@vger.kernel.org, linux-s390@vger.kernel.org, 
 linux-nfs@vger.kernel.org, tipc-discussion@lists.sourceforge.net, 
 linux-x25@vger.kernel.org, netfilter-devel@vger.kernel.org, 
 coreteam@netfilter.org, bridge@lists.linux.dev, lvs-devel@vger.kernel.org, 
 Joel Granados <j.granados@samsung.com>
Reply-To: j.granados@samsung.com

From: Joel Granados <j.granados@samsung.com>

This commit comes at the tail end of a greater effort to remove the
empty elements at the end of the ctl_table arrays (sentinels) which will
reduce the overall build time size of the kernel and run time memory
bloat by ~64 bytes per sentinel (further information Link :
https://lore.kernel.org/all/ZO5Yx5JFogGi%2FcBo@bombadil.infradead.org/)

When we remove the sentinel from ax25_param_table a buffer overflow
shows its ugly head. The sentinel's data element used to be changed when
CONFIG_AX25_DAMA_SLAVE was not defined. This did not have any adverse
effects as we still stopped on the sentinel because of its null
procname. But now that we do not have the sentinel element, we are
careful to check ax25_param_table's size.

Signed-off-by: Joel Granados <j.granados@samsung.com>
---
 net/ax25/sysctl_net_ax25.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/net/ax25/sysctl_net_ax25.c b/net/ax25/sysctl_net_ax25.c
index db66e11e7fe8..e55be8817a1e 100644
--- a/net/ax25/sysctl_net_ax25.c
+++ b/net/ax25/sysctl_net_ax25.c
@@ -141,8 +141,6 @@ static const struct ctl_table ax25_param_table[] = {
 		.extra2		= &max_ds_timeout
 	},
 #endif
-
-	{ }	/* that's all, folks! */
 };
 
 int ax25_register_dev_sysctl(ax25_dev *ax25_dev)
@@ -155,7 +153,7 @@ int ax25_register_dev_sysctl(ax25_dev *ax25_dev)
 	if (!table)
 		return -ENOMEM;
 
-	for (k = 0; k < AX25_MAX_VALUES; k++)
+	for (k = 0; k < AX25_MAX_VALUES && k < ARRAY_SIZE(ax25_param_table); k++)
 		table[k].data = &ax25_dev->values[k];
 
 	snprintf(path, sizeof(path), "net/ax25/%s", ax25_dev->dev->name);

-- 
2.43.0