From 9bb320c5cea50e7fa82a477743a6a0546eaa37b3 Mon Sep 17 00:00:00 2001 From: Christophe JAILLET Date: Sun, 18 Feb 2024 22:16:53 +0100 Subject: [PATCH] NFS: Fix an off by one in root_nfs_cat() [ 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 Reviewed-by: Benjamin Coddington Signed-off-by: Trond Myklebust Signed-off-by: Sasha Levin --- 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 effaa4247b91..c0f2e1751c33 100644 --- a/fs/nfs/nfsroot.c +++ b/fs/nfs/nfsroot.c @@ -169,10 +169,10 @@ 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; }