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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, "Paulo Alcantara (SUSE)" <pc@cjr.nz>,
        Enzo Matsumiya <ematsumiya@suse.de>,
        Steve French <stfrench@microsoft.com>
Subject: [PATCH 5.18 030/879] cifs: dont call cifs_dfs_query_info_nonascii_quirk() if nodfs was set
Date:   Tue,  7 Jun 2022 18:52:28 +0200
Message-Id: <20220607165003.550879611@linuxfoundation.org>
In-Reply-To: <20220607165002.659942637@linuxfoundation.org>
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From: Enzo Matsumiya <ematsumiya@suse.de>

commit 421ef3d56513b2ff02e563623688cb6ab4977c4f upstream.

Also return EOPNOTSUPP if path is remote but nodfs was set.

Fixes: a2809d0e1696 ("cifs: quirk for STATUS_OBJECT_NAME_INVALID returned for non-ASCII dfs refs")
Cc: stable@vger.kernel.org
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Enzo Matsumiya <ematsumiya@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 fs/cifs/connect.c |   16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -3432,6 +3432,7 @@ static int is_path_remote(struct mount_c
 	struct cifs_tcon *tcon = mnt_ctx->tcon;
 	struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
 	char *full_path;
+	bool nodfs = cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_DFS;
 
 	if (!server->ops->is_path_accessible)
 		return -EOPNOTSUPP;
@@ -3449,14 +3450,20 @@ static int is_path_remote(struct mount_c
 	rc = server->ops->is_path_accessible(xid, tcon, cifs_sb,
 					     full_path);
 #ifdef CONFIG_CIFS_DFS_UPCALL
+	if (nodfs) {
+		if (rc == -EREMOTE)
+			rc = -EOPNOTSUPP;
+		goto out;
+	}
+
+	/* path *might* exist with non-ASCII characters in DFS root
+	 * try again with full path (only if nodfs is not set) */
 	if (rc == -ENOENT && is_tcon_dfs(tcon))
 		rc = cifs_dfs_query_info_nonascii_quirk(xid, tcon, cifs_sb,
 							full_path);
 #endif
-	if (rc != 0 && rc != -EREMOTE) {
-		kfree(full_path);
-		return rc;
-	}
+	if (rc != 0 && rc != -EREMOTE)
+		goto out;
 
 	if (rc != -EREMOTE) {
 		rc = cifs_are_all_path_components_accessible(server, xid, tcon,
@@ -3468,6 +3475,7 @@ static int is_path_remote(struct mount_c
 		}
 	}
 
+out:
 	kfree(full_path);
 	return rc;
 }