[PATCH 6.7 600/713] NFS: Fix an off by one in root_nfs_cat()

Sasha Levin
2024-03-24T22:57:17Z

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 7600100ba26f0..432612d224374 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