[PATCH 5.18 030/879] cifs: dont call cifs_dfs_query_info_nonascii_quirk() if nodfs was set

Greg Kroah-Hartman
2022-06-07T21:54:56Z

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;
}