From:   Jiasheng Jiang <jiasheng@iscas.ac.cn>
To:     sam@mendozajonas.com, davem@davemloft.net, kuba@kernel.org
Cc:     netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        Jiasheng Jiang <jiasheng@iscas.ac.cn>
Subject: [PATCH] net/ncsi: check for error return from call to nla_put_u32
Date:   Wed, 29 Dec 2021 11:21:18 +0800
Message-Id: <20211229032118.1706294-1-jiasheng@iscas.ac.cn>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

As we can see from the comment of the nla_put() that it could return
-EMSGSIZE if the tailroom of the skb is insufficient.
Therefore, it should be better to check the return value of the
nla_put_u32 and return the error code if error accurs.
Also, there are many other functions have the same problem, and if this
patch is correct, I will commit a new version to fix all.

Fixes: 955dc68cb9b2 ("net/ncsi: Add generic netlink family")
Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
---
 net/ncsi/ncsi-netlink.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/net/ncsi/ncsi-netlink.c b/net/ncsi/ncsi-netlink.c
index bb5f1650f11c..c189b4c8a182 100644
--- a/net/ncsi/ncsi-netlink.c
+++ b/net/ncsi/ncsi-netlink.c
@@ -112,7 +112,11 @@ static int ncsi_write_package_info(struct sk_buff *skb,
 		pnest = nla_nest_start_noflag(skb, NCSI_PKG_ATTR);
 		if (!pnest)
 			return -ENOMEM;
-		nla_put_u32(skb, NCSI_PKG_ATTR_ID, np->id);
+		rc = nla_put_u32(skb, NCSI_PKG_ATTR_ID, np->id);
+		if (rc) {
+			nla_nest_cancel(skb, pnest);
+			return rc;
+		}
 		if ((0x1 << np->id) == ndp->package_whitelist)
 			nla_put_flag(skb, NCSI_PKG_ATTR_FORCED);
 		cnest = nla_nest_start_noflag(skb, NCSI_PKG_ATTR_CHANNEL_LIST);
-- 
2.25.1