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From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org,
	stable@vger.kernel.org
Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr>,
	Benjamin Coddington <bcodding@redhat.com>,
	Trond Myklebust <trond.myklebust@hammerspace.com>,
	Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.15 271/317] NFS: Fix an off by one in root_nfs_cat()
Date: Sun, 24 Mar 2024 19:34:11 -0400
Message-ID: <20240324233458.1352854-272-sashal@kernel.org>
In-Reply-To: <20240324233458.1352854-1-sashal@kernel.org>
References: <20240324233458.1352854-1-sashal@kernel.org>
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From: Christophe JAILLET <christophe.jaillet@wanadoo.fr>

[ Upstream commit 698ad1a538da0b6bf969cfee630b4e3a026afb87 ]

The intent is to check if 'dest' is truncated or not. So, >= should be
used instead of >, because strlcat() returns the length of 'dest' and 'src'
excluding the trailing NULL.

Fixes: 56463e50d1fc ("NFS: Use super.c for NFSROOT mount option parsing")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/nfs/nfsroot.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/nfs/nfsroot.c b/fs/nfs/nfsroot.c
index fa148308822cc..c2cf4ff628811 100644
--- a/fs/nfs/nfsroot.c
+++ b/fs/nfs/nfsroot.c
@@ -175,10 +175,10 @@ static int __init root_nfs_cat(char *dest, const char *src,
 	size_t len = strlen(dest);
 
 	if (len && dest[len - 1] != ',')
-		if (strlcat(dest, ",", destlen) > destlen)
+		if (strlcat(dest, ",", destlen) >= destlen)
 			return -1;
 
-	if (strlcat(dest, src, destlen) > destlen)
+	if (strlcat(dest, src, destlen) >= destlen)
 		return -1;
 	return 0;
 }
-- 
2.43.0