Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.36 as permitted sender) client-ip=23.128.96.36;
Feedback-ID: i31e841b0:Fastmail
From:   Ian Kent <raven@themaw.net>
To:     Al Viro <viro@ZenIV.linux.org.uk>,
        Christian Brauner <brauner@kernel.org>
Cc:     autofs mailing list <autofs@vger.kernel.org>,
        linux-fsdevel <linux-fsdevel@vger.kernel.org>,
        Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Bill O'Donnell <billodo@redhat.com>,
        Miklos Szeredi <miklos@szeredi.hu>,
        David Howells <dhowells@redhat.com>,
        Ian Kent <raven@themaw.net>
Subject: [PATCH 6/8] autofs: validate protocol version
Date:   Fri, 22 Sep 2023 12:12:13 +0800
Message-ID: <20230922041215.13675-7-raven@themaw.net>
In-Reply-To: <20230922041215.13675-1-raven@themaw.net>
References: <20230922041215.13675-1-raven@themaw.net>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

Move the protocol parameter validation into a seperate function.

Signed-off-by: Ian Kent <raven@themaw.net>
---
 fs/autofs/inode.c | 38 +++++++++++++++++++++++---------------
 1 file changed, 23 insertions(+), 15 deletions(-)

diff --git a/fs/autofs/inode.c b/fs/autofs/inode.c
index 5e061ce3ab8d..e2026e063d8c 100644
--- a/fs/autofs/inode.c
+++ b/fs/autofs/inode.c
@@ -287,6 +287,28 @@ static struct autofs_sb_info *autofs_alloc_sbi(void)
 	return sbi;
 }
 
+static int autofs_validate_protocol(struct autofs_sb_info *sbi)
+{
+	/* Test versions first */
+	if (sbi->max_proto < AUTOFS_MIN_PROTO_VERSION ||
+	    sbi->min_proto > AUTOFS_MAX_PROTO_VERSION) {
+		pr_err("kernel does not match daemon version "
+		       "daemon (%d, %d) kernel (%d, %d)\n",
+		       sbi->min_proto, sbi->max_proto,
+		       AUTOFS_MIN_PROTO_VERSION, AUTOFS_MAX_PROTO_VERSION);
+		return -EINVAL;
+	}
+
+	/* Establish highest kernel protocol version */
+	if (sbi->max_proto > AUTOFS_MAX_PROTO_VERSION)
+		sbi->version = AUTOFS_MAX_PROTO_VERSION;
+	else
+		sbi->version = sbi->max_proto;
+	sbi->sub_version = AUTOFS_PROTO_SUBVERSION;
+
+	return 0;
+}
+
 int autofs_fill_super(struct super_block *s, void *data, int silent)
 {
 	struct inode *root_inode;
@@ -335,22 +357,8 @@ int autofs_fill_super(struct super_block *s, void *data, int silent)
 		goto fail_dput;
 	}
 
-	/* Test versions first */
-	if (sbi->max_proto < AUTOFS_MIN_PROTO_VERSION ||
-	    sbi->min_proto > AUTOFS_MAX_PROTO_VERSION) {
-		pr_err("kernel does not match daemon version "
-		       "daemon (%d, %d) kernel (%d, %d)\n",
-		       sbi->min_proto, sbi->max_proto,
-		       AUTOFS_MIN_PROTO_VERSION, AUTOFS_MAX_PROTO_VERSION);
+	if (autofs_validate_protocol(sbi))
 		goto fail_dput;
-	}
-
-	/* Establish highest kernel protocol version */
-	if (sbi->max_proto > AUTOFS_MAX_PROTO_VERSION)
-		sbi->version = AUTOFS_MAX_PROTO_VERSION;
-	else
-		sbi->version = sbi->max_proto;
-	sbi->sub_version = AUTOFS_PROTO_SUBVERSION;
 
 	if (pgrp_set) {
 		sbi->oz_pgrp = find_get_pid(pgrp);
-- 
2.41.0