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From:   Ma Ke <make_ruc2021@163.com>
To:     jmaloy@redhat.com, ying.xue@windriver.com, davem@davemloft.net,
        edumazet@google.com, kuba@kernel.org, pabeni@redhat.com
Cc:     netdev@vger.kernel.org, tipc-discussion@lists.sourceforge.net,
        linux-kernel@vger.kernel.org, Ma Ke <make_ruc2021@163.com>
Subject: [PATCH] tipc: Fix uninit-value access in tipc_nl_node_get_link()
Date:   Fri, 13 Oct 2023 15:04:08 +0800
Message-Id: <20231013070408.1979343-1-make_ruc2021@163.com>
MIME-Version: 1.0
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Names must be null-terminated strings. If a name which is not 
null-terminated is passed through netlink, strstr() and similar 
functions can cause buffer overrun. This patch fixes this issue 
by returning -EINVAL if a non-null-terminated name is passed.

Signed-off-by: Ma Ke <make_ruc2021@163.com>
---
 net/tipc/node.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/net/tipc/node.c b/net/tipc/node.c
index 3105abe97bb9..a02bcd7e07d3 100644
--- a/net/tipc/node.c
+++ b/net/tipc/node.c
@@ -2519,6 +2519,9 @@ int tipc_nl_node_get_link(struct sk_buff *skb, struct genl_info *info)
 		return -EINVAL;
 
 	name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
+	if (name[strnlen(name,
+			 nla_len(attrs[TIPC_NLA_LINK_NAME]))] != '\0')
+		return -EINVAL;
 
 	msg.skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
 	if (!msg.skb)
-- 
2.37.2