From: Yiqi Sun <sunyiqixm@gmail.com>
Date: Tue, 11 Nov 2025 07:05:39 +0000 (+0800)
Subject: smb: fix invalid username check in smb3_fs_context_parse_param()
X-Git-Tag: v6.12.62~25
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ef9b1e6b8f90282b098a29442639b7759be1374b;p=thirdparty%2Fkernel%2Fstable.git

smb: fix invalid username check in smb3_fs_context_parse_param()

[ Upstream commit ed6612165b74f09db00ef0abaf9831895ab28b7f ]

Since the maximum return value of strnlen(..., CIFS_MAX_USERNAME_LEN)
is CIFS_MAX_USERNAME_LEN, length check in smb3_fs_context_parse_param()
is always FALSE and invalid.

Fix the comparison in if statement.

Signed-off-by: Yiqi Sun <sunyiqixm@gmail.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/fs/smb/client/fs_context.c b/fs/smb/client/fs_context.c
index 9a4492106c25..17133adfe798 100644
--- a/fs/smb/client/fs_context.c
+++ b/fs/smb/client/fs_context.c
@@ -1415,7 +1415,7 @@ static int smb3_fs_context_parse_param(struct fs_context *fc,
 			break;
 		}
 
-		if (strnlen(param->string, CIFS_MAX_USERNAME_LEN) >
+		if (strnlen(param->string, CIFS_MAX_USERNAME_LEN) ==
 		    CIFS_MAX_USERNAME_LEN) {
 			pr_warn("username too long\n");
 			goto cifs_parse_mount_err;