From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Jiasheng Jiang <jiasheng@iscas.ac.cn>,
        Jakub Kicinski <kuba@kernel.org>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.15 48/73] net/ncsi: check for error return from call to nla_put_u32
Date:   Mon,  3 Jan 2022 15:24:09 +0100
Message-Id: <20220103142058.461511222@linuxfoundation.org>
In-Reply-To: <20220103142056.911344037@linuxfoundation.org>
References: <20220103142056.911344037@linuxfoundation.org>
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From: Jiasheng Jiang <jiasheng@iscas.ac.cn>

[ Upstream commit 92a34ab169f9eefe29cd420ce96b0a0a2a1da853 ]

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>
Link: https://lore.kernel.org/r/20211229032118.1706294-1-jiasheng@iscas.ac.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 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 bb5f1650f11cb..c189b4c8a1823 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);
-- 
2.34.1